Cultivating Pygmy Drosera

I have been growing Pygmy Drosera for about 4 to 5 years, and have certainly learned a lot about this fascinating group of plants in that time. Not having the luxury of regularly seeing these plants in the wild increases my enthusiasm to grow them and I’m sure this applies to many of you as well.

When I first started growing CP’s I would follow the cultivation directions provided in CP books religiously. If the book said use this exact mix for Nepenthes, I would. As you would expect, many plants died because treating all plants within a single group alike is simply not the answer to successful growing. Some people tend to group plants according to origin, and treat species in that group the same way. While this method yields better results than the previous one, it is not always ideal.

So how does this relate to my experiences of cultivating Pygmy Drosera? It’s a common practice when growing these plants to sow seed or gemmae in a pot full of a standard 1/3 sand, 2/3 peat or perhaps a 50/50 mix. While it is true that there are hardy species which will grow in just about everything, many of the more sought after species don’t. From my experience, treating pygmy Drosera species on an individual basis is the way to good growing. While it is certainly more time consuming than potting up in a standard mix, you are far more likely to be successful. I choose to grow only Australian native CP’s (mainly Pygmies, but Tuberous Drosera as well), so using a different mix for each species is easy for me since my collection is not as large as some. Climate is an important factor, which I would love to be able to change for each species, but that is totally impractical. Perhaps if you have a large sum of money lying around, it might be easy! So as far as climate goes, all of my Pygmies are treated the same.

My plants are grown under a canopy of Solarweave, a woven PVC fabric which allows excellent light transmission, another most important factor when growing Pygmies, as the colour of the plants appears to be directly related to the amount of light they receive.

Now onto the good stuff, the facts that I think you need to know. While there is certainly no right and wrong mix to use, as you would expect, a mix as close to that of the plants natural habitat seems to give the best results. From my visits to Western Australia I have established that many species grow in fine white sand, and for most people this is easy enough to obtain. Species, which in nature grow in pure sand, will most definitely grow in sand of various sizes, but I tend to use a grain size that closely matches that of the natural conditions. This usually means the use of very fine sand. Apart from being more aesthetically pleasing to the eye, finer grained sands are usually more practical, for instance gemmae tends to strike better in a finer grained sand.

Sand is graded commercially by passing it through sieves that are numbered according to the openings per inch, e.g. 30/60 grade sand is the coarsest I use for Pygmy Drosera and the majority is much finer. I don’t normally purchase graded sand, I just select it by recognising that it is a fine grade and the colour I’m interested in obtaining.

Probably one of the hardest soils to find a substitute for, outside Western Australia, is laterite. Drosera barbigera in one species that grows in laterite, and many growers have reported it a difficult plant to keep going. After a couple of attempts at growing this species, I’ve finally had success. The mix I use is mostly red loam, with some fine (powdery yellow) sand and quartz chunks (which were already in the loam when I got it). Obviously it will be difficult for anyone to obtain the exact same sands I have used, so some experimentation will be required.

For more information on laterite see further articles in this section.

The use of small pots is okay for some species, mostly the plants preferring swampy areas, e.g. D. pulchella, D. enodes and some of the D. nitidula sub species and hybrids, which grow where the water level is much closer to the soil surface. For most Pygmies however, a large pot is beneficial. The bigger you can make it the better. I use pots ranging from 19cm to 27cm in height. Pygmies root are usually longer than you think.

Another benefit of big pots is the width of the pots. In most cases the plants growing in the middle of the pots are the largest and healthiest. The soil tends to heat up on the sides making it less than ideal for the plants to grow in. With a larger pot you have a much larger cool area in the middle for the plants to grow. On the down side it certainly makes it difficult to bring my plants along to the ACPS meetings since large pots of sand are very heavy.

Despite what I have said above about the grouping of plants, there are many Pygmies that grow in virtually identical conditions to others. They are listed under various sections because I have either found them in that particular soil type, or have seen photographs of them growing in that soil type, it is not generalization of what each species grows in. I have also tried and tested plants in these soils, with good results.

Plants found in white silica sands of various sizes:-
D. callistos
D. closterostigma – also does well in a very fine yellow sand.
D. eneabba
D. ericksoniae
D. leioblastus
D. leucoblasta
D. nitidula ssp leucostigma
D. nitidula ssp allanostigma x ericksoniae – does better with some peat added.
D. nitidula ssp omissa
D. nitidula ssp omissa x pulchella
D. paleacea ssp paleacea
D. pulchella – does better in peaty sands as it is found in swampy areas.
D. pygmaea – prefers really fine grained sand.
D. scorpioides

Plants found in laterite soils (or my red loam sand mix):-
D. barbigera – red loam with fine sand.
D. lasiantha – red loam with small amounts of coarse white sand
D. sewelliae – red loam with small amounts of coarse white sand
D. silvicola– red loam with small amounts of coarse white sand
D. stelliflora – red loam with small amounts of coarse white sand

Plants found in swampy soils (various mixes of peat and different grades of sands)
D. ssp ‘Carbarup’ – prefers only a small amount of peat, mainly sand mix.
D. dichrosepala
D. enodes – black peaty sand.
D. helodes
D. occidentalis ssp occidentalis
D. occidentalis ssp australis
D. pulchella
D. roseana

There are of course other plants which are found in soil types not listed, such as D. mannii which is found in a clay-ish soil. This is more difficult to substitute since clay soil types are usually more complex, perhaps containing different amounts/types of sand, organic matter etc. Fortunately this species doesn’t mind a standard peat/sand mix. When potting up this year, I ran out of sand for some D. pulchella gemmae, so I put them in pure red loam to see what would happen. To my surprise they are the healthiest looking D. pulchella I have had.

When using sands, there are some things to be aware of. The obvious one is to do your mixing in an open area, and wet the sand, so there is no risk of particles flying around for you to breath in. When planting gemmae on pure sand, the soil surface tends to dry out quickly, so spraying with water every day or so is necessary until the plant sends a root into the soil.

Some sands also tend to produce a small salt build up in the soil surface. If in sufficient quantities it can kill plants. One way I have considered getting around this is to water from the top down, instead of the tray method. I have a few native terrestrial orchids growing in sandy mixes with a layer of old gum leaves on top, both to act as nourishment and to stop the sand going every where when I water them. This is certainly something I plan on trying next year on some Pygmy Drosera species. Obviously it is not suitable for all, but plants such as D. silvicola, D scorpioides and D. stelliflora can all be found growing in leaf litter in their natural habitats.

I have only covered a small amount of what can be done to grow Pygmy Droseramore successfully. I would advise anyone interested in this group of plants to try and do as much research as possible into their natural habitats and growing conditions. If possible, a visit to Western Australia to see plants in their natural environment is a must, and with the current rate of land clearance in Western Australia, some may not be there much longer. As I stated earlier, there is no right or wrong way to grow these plants, but by experimenting to find the best way reproducing their natural conditions you should be able to grow great plants.

Reproduced from the Australian Carnivorous Plants Society Bulletin Volume 18 – 4 With kind permission from the author.

Posted in Cultivation

A Field Trip to Albany

A Field Trip to Albany, and Environs, Western Australia

Robert Gibson

                In mid June 1995 I had the pleasure of visiting Albany, on the south coast of Western Australia and travelled as far west as Walpole and as far east as Esperance. On this trip I saw 26 species of carnivorous plant in the wild. The highlights of the trip were seeing Cephalotus follicularis and flowering plants of Utricularia menziesii in the wild and finding Drosera erythrorhiza ssp collina and D. macrantha ssp macranthaoutside their published ranges.

I had the pleasure of seeing the Western Australian pitcher Plant in the wild just east of Albany. A cluster of plants grew on a small south-facing natural bench on the edge of a swamp in an area supporting dense low woodland. At first the plants were hard to find due to the density of the shrubs and understorey of sedges, and they were identified by their large, glossy clusters of non-carnivorous leaves.

Approximately 20 pitcher plants grew in an area 3m by 1m, many in close proximity suggesting that they may be clones on the same root system. Each plant had a sparse rosette of leaves, to 15 cm diameter, consisting of 1 to 5 non-carnivorous leaves and 1 or 2 pitchers. The non-carnivorous leaves were up to 8cm long (including petiole) and to 4.4 cm wide, and were generally held horizontally. One of the non-carnivorous leaves had a bifurcated tip and all had a few small white scale insects on them. The newly produced pitchers  were between 5 and 30 mm long, many of which had not yet opened. Most pitchers were covered by the non-carnivorous leaves and a few were partially buried in the thin layer of humus above the peaty sand substrate. Due to the generally low light conditions all but one of the pitchers were fully green in colour; the one exception, on the edge of the colony,  had red pigmentation on its unopened lid. The plants had just completed a flush of growth (pitcher formation) and only very immature, indistinguishable new growth was present in the plants growing points.

Dead leaves and pitchers did not persist around the plants and there were no sign of scapes. When Cephalotus is seen growing at  the  base of tall and dense vegetation it is easy to see how the tall scapes produced by this species, with its strongly fragrant flowers and wind dispersed seeds (Erickson, 1968) is advantageous to promoting cross-pollination of flowers and enhancing seed dispersal. The only plant-animal interactions seen at this site were the slightly chewed edges of some non-carnivorous leaves; some scale insects; a spider web across the entrance of one pitcher; and a detached, torn pitcher possibly due to the travels of a kangaroo. Due to the inconspicuous nature of the pitchers, the way they are often covered by the non-carnivorous leaves, or partially buried in the substrate, and the 1 to 2 m tall overstorey of tangled  stems and branches, it appears that the main prey consists of crawling invertebrates. This would change in the first few months after a bush fire has cleared the overstorey when there is much more chance of flying insects also finding their way into the pitchers.                Cephalotus follicularis was found growing in the company of Drosera pulchella, D. erythrorhiza ssp collina, and near plants of D. pallida/ erythrogyna and D. erythrorhiza ssp erythrorhiza. The plants grew in well-drained moist peaty sand slightly higher than the adjacent damp soil of a permanent swamp, in well shaded conditions.

Utricularia menziesii

                Utricularia menziesii was seen near Mt. Manypeaks and at Cape Le Grande National Park growing in small coastal plain swamps and in thin, moss-covered sandy soil on granite outcrops. These gregarious plants were easily seen by their tight cluster of lime-green leaves, to. 1.5 cm diameter. Each plant, or tuber cluster, produced between 2 and approximately 30 leaves. Within populations the size of the leaves often varied between plants; those which produced larger leaves produced fewer than those of other plants of similar tuber cluster size. Between 5 and 10% of plants per colony produced scapes; these were in variable stages of development and varied from those emerging from above the leaves and those with fully opened flowers. Even in the rare case of tuber clusters with more than one scape, these were often in different stages of development. At Cape Le Grande National Park some flower colour intensity was seen. Even though only 2 open flowers were seen here the red pigment intensity of the sepals varied between plants. Most plants had a blood red calyx, held on a green scape, but a small number of plants had a paler red calyx. The open flowers were stunning, and were held on scapes to 3cm tall so that the long spur of the flower was held just above the ground. In the coastal swamp near Mt. Manypeaks one plant was found which had a two flowers on the same scape, although these were several weeks away from opening.

This delightful bladderwort often grew in the company of other carnivorous plants. On granite outcrops it grew with Drosera microphylla, and in the coastal plains it grew with D. tubaestylus, D. menziesii ssp. menziesii and D. pulchella.

Drosera andersoniana

A few plants of the tuberous Drosera andersoniana grew on a low granite outcrop north of Hyden. This undulating outcrop was partially buried by a mantle of thin, seasonally damp to saturated, in which this sundew thrived. The vibrant red rosettes grew to 2.5cm diameter, had distinctive rounded lamina, were exposed to full sun and grew amongst Pincushion Grass (Borya sp) and terrestrial orchids. No plants had yet begun to form a stem and no other carnivorous plants were seen at this site.

Drosera browniana

Red leaved rosettes of the tuberous Drosera browniana grew on, and adjacent to a granite outcrop near Hyden. The leaves grew to 5cm long and were of variable width, 8 to 25 mm maximum width, between plants. Most rosettes were between 4 and 6cm diameter and often grew so thickly that they carpeted the moss and Casuarina leaf covered moist sandy soil in which they grew. Only a few plants had flowered. One plant was found was found with a recently opened the flowers, one of the last of the season, although the white petals were closed when seen. The single pedicelled flowers are pendulous in fruit, then mostly buried by the growing leaves. This species grew near D. macrantha ssp macrantha and D. subhirtella ssp subhirtella.

Drosera bulbosa ssp bulbosa

Golden green rosettes of the tuberous Drosera bulbosa ssp bulbosa were seen at one location, north of Borden, in a shallow gully beside the road on the edge ofMelaleuca woodland. These scattered rosettes were up to 3cm diameter, with up to 10 leaves, each of which had a conspicuously raised midrib. Many plants consisted of 2 to 4 crowded rosettes which had emerged from the same small area and whose leaves and scapes now jostled for space; indicating  that daughter tubers had been produced adjacent to the parent tuber. At least 30% of plants seen at this colony  had flowered, a few plants still had unopened buds. Three to thirty flowers were produced per rosette, each on its own pedicel, and where daughter rosettes were  flowering together these clusters produced up to 70 flowers between them. The only other carnivorous plant species seen at this site was D. subhirtella ssp subhirtella.

Drosera dichrosepala

Roadside colonies of the pygmy sundew, D. dichrosepala were seen within 20 km east and west of Albany, often discernible by the glowing drops of mucilage backlit by the morning sun. The round red leaved rosettes grew to 1.5 cm diameter, on short stems to 1cm tall, which grew in tight spaced colonies. They grew on dry-surfaced sandy clay soil, which had often been exposed for shallow road cuttings. No sign of spent scapes were seen but this species had developing gemmae, in all stages of development, in the centre of the rosettes seen. This species grew with, or near, D. erythrorhiza ssp erythrorhiza, D. pallida and D. pulchella.

Drosera erythrorhiza ssp erythrorhiza

Colonies of the tuberous Drosera erythrorhiza ssp erythrorhiza were seen in a range of habitats in many areas visited. The rosettes were up to 5cm diameter and consisted of between 2 and 5 leaves round leaves which were green to orange in colour. Due to the abundance of daughter tubers produced on stolons by this subspecies (Lowrie, 1987) when found, this subspecies occurred as close-spaced colonies of up to several hundred rosettes covering up to 3 square metres. At most only 1 to 3 plants in any colony had developing scapes. This species grew in well-drained sandy soil at the Stirling Range and east of Albany; in thin sandy soil on granite outcrops around Albany townsite; in raised areas of peaty soil in sedge swamps near Albany, and in dry-surfaced sandy clay soil and laterite derived soil with a surface cover of iron piesoliths (“pea gravel”) east of Albany. This species was found growing with , or near, Cephalotus follicularis, Drosera dichrosepala, D. erythrorhiza ssp collina, D. hugelii, D. paleacea ssppaleacea, D. pallida and D. pulchella.

Drosera eryrthrorhiza ssp collina

Attractive large rosettes of a tuberous taxa tentatively identified as Drosera erythrorhiza ssp collina were found at the Stirling Range and in Jarah woodland east of Albany. The rosettes, to 10 cm diameter, had 6 to 10 ovate leaves, which commonly had a red tinged edge. This subspecies often grew with D. erythrorhiza ssp erythrohiza and occurred as small colonies of relatively widely spaced rosettes; however, some asexual reproduction did occur in which the daughter tuber was produced immediately beside the parent tuber. Only a few plants in a few colonies had developing scapes. This subspecies was found mainly in open woodland, in moist well-drained sandy soil, in the company of Cephalotus follicularis, D. erythrorhiza ssp erythrorhiza, D. hugelii, D. pallida/ D. erythrogyna, and D. pulchella and less commonly, in moist sandy-clay soil in more open conditions, in the company of D. hugelii and D. pulchella.  The occurrence of this form on this field trip is a modest range extension of its published range (Lowrie, 1987).

Drosera glanduligera

Golden green rosettes of the winter-growing annual Drosera glanduligera were found at only one location. Approximately 100 km east of Southern Cross. Plants grew in sodden, to saturated, thin, coarse-grained sandy soil on, and adjacent to, granite outcrops in generally unshaded positions. The rosettes grew to 3cm diameter and had not yet begun to produce scapes. This species grew with D. andersoniana and D. subhirtella ssp moorei.

I was able to see for myself the incredibly rapid speed at which the outer, longest stalked retentive glands are able to move simply by placing my finger on a few leaves. This had been reported to me by I.. Snyder and F. Rivadavia (pers. comm., 1995) and is poorly known characteristic of this delightful species.

Drosera hugelii

Two forms of the erect, bell-shaped leaves of the tuberous Drosera hugeliiwere on my trip. The most widespread form was a robust, generally golden green form which grew to 50 cm tall, and was seen on lower elevations of the Stirling Range and in a sedge swamp near Albany, some if which were in scape. A colony of attractive, strongly red pigmented plants, to 10 cm tall, was seen on the summit plateau of Bluff Knoll in the Stirling Range, growing to within 100m of the summit. This “alpine form” is a good candidate for subspecies status (P. Mann, pers. comm., 1995). This species grew with, or near, D. eryrthrorhiza ssp erythrorhiza, D. pallida/D. erythrorgyna, D. pulchellaand D. roseana. The alpine subspecies grew with D. stolonifera ssp monticola.

Drosera macrantha ssp macrantha

Robust climbing or scrambling plants of the tuberous Drosera macrantha sspmacrantha, to 80 cm tall, were seen in many of the eastern and inland areas visited. The generally golden green plants, with concave lamina held in alternate whorls of three, and with short stalked retentive glands over the upper half of the stem, were seen in a number of habits; in open woodland near a granite outcrop at Hyden; in well-drained sandy soil at the Stirling range; in well-drained laterite-derived soil west of Ravensthorpe; in thin sandy soil on a granite outcrop at Cape Le Grande; and in thin sandy soil around a granite outcrop 150 km north of Kalgoorlie. The latter represents a significant range extension of this species. In most cases the plant were just starting to produce flower buds. This species was found growing with, or near D. erythrorhiza ssperythrorhiza, D. browniana, D. subhirtella ssp subhirtella and D. zonaria.

Drosera microphylla

Vibrant red erect plants of the tuberous Drosera microphylla, to 15 cm tall, were found growing in abundance on the northern flanks of Mt. Cape Le Grande. The plants grew in thin, sopping, moss-covered sandy soil with pincushion plant (Borya sp.) and Utricularia menziesii. Plants had not yet begun to develop scapes but from a previous visit to this site the plants are known to be white petalled (Gibson, 1992).

Drosera menziesii ssp menziesii

Erect, red, non-flowering plants of the tuberous Drosera menziesii sspmenziesii, to 30 cm tall were seen at two locations visited. One was a granite outcrop in Karri forest east of Denmark where the plants grew in abundance in thin, moss-covered soil. The other site was a near Mt. Manypeaks where a single plant grew in moist sandy peat at the edge of a small swamp. At the second site the plant grew near U. menziesii, D. pulchella, D. scorpiodes and D. tubaestylus.

Drosera modesta

A few colonies of golden green tuberous Drosera modesta were found in a range of locations on the south coast. This species often grew in shaded conditions, in well-drained, moist sandy soil on the floor of tall Eucalyptus-dominated woodland. Plants were in many stages of development, from rosettes to 1.5 cm diameter, to scrambling plants to 30 cm tall. The alternate, triangular leaves, with two prominent projections, and common formation of daughter tubers at the end of inclined stolons were key features in identifying this species. This sundew often grew apart from other carnivorous plants but at one location, just east of Albany, it grew near D. pallida.

Drosera neesii ssp neesii

A few scattered plants of Drosera neesii ssp neesii were seen at two sites near Albany in early December. The plants, to 40 cm tall, were just starting to go dormant, but the large, lime green shield shaped leaves and tips of the bright yellow petals on the dead flowers were clearly visible. The plants grew in moist peaty sand in either open  woodland, near the Cephalotus site, or grew in more open low woodland which had been recently burnt. This species grew in marginally more elevated ground then Drosera pulchella at both sites visited. It also grew near Cephalotus and Drosera occidentalis ssp australis at the site.

Drosera occidentalis ssp australis

Only a few plants of this diminutive pygmy sundew, D. occidentalis sspaustralis, were seen on the expedition, and these were at Cape Le Grande. The vibrant red rosettes, to 8 mm diameter, grew in moist peaty soil, with a variable concentration of clay and sand, at the margin of swamps and lakes.

REFERENCES

Erickson, R. 1968. Plants of Prey In Australia. UWAP
Gibson, R. 1992. Carnivorous Plants of the Esperance District, Western Australia. Bulletin of the Australian Carnivorous Plant Society, Inc.
Lowrie, A. 1987. Carnivorous Plants of Australia: Volume 1, UWAP.
Lowrie, A. 1987. Carnivorous Plants of Australia: Volume 2, UWAP.

ACKNOWLEDGEMENTS
I wish to thank Todd, Lynda and Brian for providing access to the Cephalotussite, and Phill Mann for providing details of some excellent plant locations.

Posted in Field Studies

Carnivorous Plants around Harvey, WA

Carnivorous Plants Around Harvey, Western Australia

Robert Gibson

                In September, 1995, I visited Phill Mann and spent an afternoon looking for sundews in the hills east of Harvey. Our brief expedition proved to be very successful as we found 11 species of Drosera, many in the peak of their growth cycle and growing in great abundance. The following is an account of the species seen and their growing conditions.

Drosera erythrorhiza ssp ? collina

Large green to orange robust rosettes of a taxa of Drosera erythrorhiza very similar to ssp collina were seen in a few locations in the Jarrah forest. The first site was a shaded, poorly defined creek bed where the scattered rosettes, to 7cm diameter, grew in peaty, moist soil. The plants grew with D. gigantea and none had flowered.

This taxon grew in greater abundance in an area of lower density trees on an area with orange, rounded gravel piesolite-covered soil. The area was well drained, and the irregular, very coarse soil was uncomfortable to lie on. Here, however, this attractive variant grew in abundance. The fully bedewed rosettes to 10 cm diameter were variably orange pigmented and often grew in small clusters. This taxon, with 4 to 6 ovate leaves, and with rare asexual reproduction appears closest to ssp. collina. More work, however, is warranted on this, and other taxa in the D. erythrorhiza complex.

Drosera gigantea

                Drosera gigantea was seen in two sites, the first was in the bed of poorly formed creek in open Jarrah forest, on soil derived from laterite. The soil was moist, with some accumulation of organic matter on the surface. The plants grew amongst clumps of sedges, in the shadow of a range of shrubs of the Myrtaceae family. Despite the time of year the D. gigantea plants here were still forming the initial branches and were months away from flowering. Many still looked like stalks of asparagus, and they growing the company of variably green to orange rosettes, to 10 cm diameter, of D. erythrorhiza ssp ? collina.

The second site was on a sodden, north facing granite slope which supported few woody plants. An abundance of annual and summer-dormant, often tuberous, herbs grew abundantly in the moss, and Borya-covered thin soil. Here D. gigantea grew in abundance and, in contrast to the previous site, most plants were in flower. The plants were generally golden green, although some plants had red stems, and produced a golden green glow when backlit by light of the setting sun. The plants grew to 70cm tall, and were most abundant towards the top of the granite outcrop, perhaps due to the slightly deeper soil where the slope was not too great. In places the plants grew in such abundance that it was difficult not to damage plants when moving around the site. Despite the abundance of flowers produced by the plants here in most general this species rarely sets seed in the wild. Perhaps the abundance of Drosera gigantea plants at this site reflects prolific asexual reproduction from the production of daughter tubers underground and by the formation of tuber s from the leaves of fallen plants. Perhaps this species needs a fire the summer before to trigger a greater amount of seedset? Thissundew grew with D. stolonifera ssp stolonifera, D. macrantha ssp macrantha and D. glanduligera at this amazing site.

Drosera glanduligera

Drosera glanduligera were seen in the area. The plants had golden green rosettes to 3cm diameter, many of which were just starting to produce scapes. Plants were seen in moist sandy peat soil of a swampy creek bed which slowly cuts its way through the Jarrah forest. Plants were also seen growing in sodden moss, amongst boulders, on a north facing granite outcrop over which fresh water was continually seeping. This annual grew in the company of Drosera pallida, D. gigantea, D.stolonifera ssp stolonifera and D. macrantha ssp. macrantha.

Drosera macrantha ssp macrantha

The first species of sundew found on the trip were climbing plants of Drosera macrantha ssp macrantha which grew in well drained laterite-derived soil on roadside embankments. Many plants grew immediately beside the road. Many plants were in flower, and showed some of the range in petal size and colour which is found in this variable taxa.

Abundant plants were also seen growing in moss, and thin soil on a moist granite outcrop in the company of D. gigantea, D. glanduligera and D. stolonifera sspstolonifera.

Drosera marchantii ssp marchantii

Numerous plants of the erect growing Drosera marchantii ssp marchantiigrew in well-drained laterite-derived soil on roadside hills, and in clearing in the jarrah forest. This attractive species has a swollen base, with many short, bract-like leaves at the base of its golden green stem.  Many plants were in flower at the time of our visit and the sweetly scented, rich pink petalled flowers, to 2cm diameter were a sight to behold. Many plants grew with D. macrantha ssp macrantha.

Drosera neesii ssp neesii

A few erect plants of golden green Drosera neesii ssp neesii were found in damp peaty sandy soil in the swampy creek. The scattered plants often grew in, or adjacent to channels. They were up to 20 cm tall and were at least a month away from flowering, and could have either pink or yellow petals. This species has a preference to growing in damp peaty soil which rarely fully dries out during the summer, and was seen to grow near D. glanduligera and D. pallida.

Drosera pallida

A few slender climbing plants of Drosera pallida scrambled over low woody shrubs on the drier parts of the swamp in the Jarrah forest. This species has a smooth, slender dark green stem with rounded leaves in threes with bright red long stalked retentive glands. In leaf and flower size it is a variable species, which is widespread in south west Western Australia. In this area it grew near D. neesii ssp neesii and D. glanduligera. However, from what I’ve seen elsewhere in the state this species is probably widespread in the Jarrah forest in the area but was not seen.

Drosera pulchella

A few non-flowering rosettes of Drosera pulchella grew beside and in the creek bed of a small ephemeral creek. The rosettes were variably hidden by grasses and sedges, and grew in soil which was likely to remain moist well into the summer. The plants grew downslope of an area cleared for Eucalyptus plantations, which otherwise would have supported a range of other sundew species.

Drosera scorpiodes

Attractive, robust, often long stemmed plants of Drosera scorpiodes grew in an area of open Jarrah forest, on a coarse, well drained surface layer of which is composed of rounded, orange, gravel-sized piesolites. The rosettes were fully bedewed, up to 4cm diameter, on often leaning stems to 10cm long, and had the first scapes of the season just emerging from the centre of the rosette. This species grew with D. erythrorhiza ssp ? collina, and was very attractive when backlit by sunlight.

This population of D. scorpiodes is unusual in two respects. Either it is a very isolated population or it shows that this species is more widespread than has been previously reported. In addition the petal color of these plants is an attractive dark pink. It is a very attractive form of the species.

Drosera stolonifera ssp compacta

A few very red plants of Drosera stolonifera ssp compacta grew on the open floor of Jarrah forest and were readily seen from a moving car. The plants grew upright, with up to 4 stems, and, rarely, the remains of a scape. Unlike Drosera stolonifera sspstolonifera this subspecies grew in scattered colonies, was self-supporting and the above ground growth was immediately above the tuber. The plants grew in moist, but well drained, sandy soil, probably on laterite. The area where the plants had been growing had been burnt the previous summer and the forest floor was still very open. A thin layer of bright green moss grew on the charcoal rich layer on the soil surface. No other sundews were found growing with this species.

Drosera stolonifera ssp stolonifera

Stunning red, multi-branched plants of Drosera stolonifera ssp stoloniferagrew in abundance in damp, shallow soil on a prominent granite outcrop over which water was continually flowing. The stunning red plants stood out from the accompanying grasses and summer dormant herbs and had between 3 to 6 fully bedewed branches, to 15 cm long. Many of the plants had flowered and most flowers had set seed, ripe seed was being shed from the dieing scapes at the time of our visit. This species grew with D. gigantea, D. glanduligera and D. macrantha ssp macranthaon the more exposed part of the granite outcrop, but this species also grew upslope on the same granite outcrop in the Jarrah forest. This very attractive species buries its tuber deeply into crevices in the granite. The above ground growth initially grows horizontally before the leaf rosette, with basal leaves branching stems, and, if large enough, scape is produced.

Only a few plants of the winter-growing annual herbs assist in holding the plant upright. This species looked stunning when the large colonies of it glowed red by the light of the setting sun behind them.

The nine species of tuberous Drosera were found in all three subgenera and it was interesting to see which plants grew together and the environments in which they grew. The two species of pygmy Drosera seem grew in very different environments.

It was excellent to see such a range of native sundews growing in the wild on a short trip. It provides food for through of what could be found in the area by spending more time and travelling further in the region.

Acknowledgments:

I wish to thank Phill Mann  for his company and showing me a few plants in his “backyard”.

Posted in Field Studies

Carnivorous Plants near Mt. Lesueur, WA

Originally appeared in Carnivorous Plant Newsletter, 1998, 27:3, p81-84. ISSN #0190-9215

Carnivorous Plants near Mt. Lesueuer, Western Australia

Robert Gibson

On the weekend of September 16 and 17, 1995, I had the pleasure in participating in a vegetation survey on a farm near Mt. Lesueur, approximately 250 km north of Perth.  During this survey a number of carnivorous plants were found, 13 species of Drosera and Byblis gigantea, which are described below.

Byblis gigantea
Byblis gigantea was found in two sites on the farm, both of which were on hillslopes growing in a soil derived from fine, possibly windblown, quartz  sand and fragments of massive lateritic ironstone. The plants were found on disturbed ground, along firebreaks, and would have undoubtedly have occurred in the adjacent undisturbed low heathy vegetation known as ‘kwongan’.

At least ten mature plants were found at each site, and were in active growth, some of which had commenced flowering. The plants grew to 30cm tall, had one to three stems each, with erect linear leaves to 22cm long. At the lower part of the stem the leavers were close together, with 1 to 3 mm internodes. The more recent growth had internodes 1 to 2 cm apart and single, auxiliary flowers, the latter though were not present in the lowest 2cm of more rapid stem elongation. The pedicels were just shorter than the leaves and held a single, outfacing iridescent purple petalled flowers to 3cm diameter. A single seedling, with leaves to 5cm long and a poorly developed stem was found at one site.

The plants were fully bedewed and had caught a range of flying insects, including aphids, midges and a smaller number of bush flies. Most plants had at least two lime-green Drosera bugs on them which moved readily over the bedewed plants. No insects were seen visiting the open flowers.

These plants are part of the northern population of this species which differs from plants around Perth. These plants are generally smaller; have shorter leaves; grow in well drained soil on hillslopes; produce stems with less branching and fewer  plants from the root-system of established plants and had petals of the same colour throughout. They differ in choice of habitat form the southern population which prefer to grow in deep sand on the edge of swamps, and in the flower colour which includes a flattened, darker purple base on the inside of each petal

Drosera barbigera
Large numbers of the attractive and robust pygmy sundew, Drosera barbigera, were seen on the top and flanks of one of the laterite hills on the property. The plants grew in ironstone soil, with variable amounts of sand, often in colonies of a few tens to hundreds of plants.  The semi-erect rosettes grew to 3cm diameter, on the end of often-prostrate stems to 5cm long.  Many plants were in flower, with one to two scapes each., These grew to 10 cm long and had a tight cluster of flowers with conspicuously hairy sepals. The vibrant orange petalled flowers, to 1cm diameter, were open under sunny conditions, or when in the protection of adjacent low shrubs under cloudy conditions. The petals had a dark red base which was adjacent to the similarly coloured ovary and its three threadlike styles. The anthers produced pale yellow pollen which stood out against this dark coloured zone. A brown beetle was seen visiting one flower and may act as a pollinator.

Drosera enneaba
Large colonies of the pygmy sundew, Drosera enneaba, grew in sandy soil on the flanks of laterite plateaus. The glistening rosettes, to 2cm diameter, were seen in abundance on the fire trails. The orbicular red tentacled lamina occurred on the end of straight-sided petioles and formed a flat rosette. Many plants were in flower and had one, rarely two scapes , to 15 cm tall. The sweetly scented flowers had all white-petals, save for the distinct red dot near the ovary

Drosera erythrorhiza ssp ?magna
Scattered colonies of closely spaced rosettes of a taxon of the tuberous sundew, Drosera erythrorhiza, were seen throughout the farm in areas of deep sand, and on the edge and top of laterite plateaus. The rosettes were generally very red, with up to 8 leaves and were up to 8cm diameter, although most were smaller. Some plants were still bedewed although many were now starting to die down. A few still had the remains of scapes, which had already shed their seed. From the number of leaves and the size of the plants they were tentatively ascribed to subspecies magna, although some colonies could have been subspecies erythrorhiza. The close spaced colonies of these plants indicates either that some asexual reproduction occurs or the seed generally does not travel far from the parent plant. The identity of this taxon could be confirmed by looking at the root system and in checking the timing of flowering with respect to maturation of the rosette. Whatever its identity it is a large and beautiful variant in leaf.

Drosera gigantea
Scattered plants of the erect growing tuberous Drosera giganteawere seen in two locations in the area. One was in a creek bed, in water to 10 cm deep, and adjacent parts of the bank where plants to 40cm tall were seen. These were in bud, with many branches, few of which had mature leaves. The second site was in deep sand several hundred metres from the nearest creek bed. Some of these plants were already in flower although many had started to go dormant with the shrivelled remains of aborted inflorescences. At the second site a few plants had deep red stems.

Drosera glanduligera
Flowering rosettes of the annual Drosera glanduligera were found in the area. They grew  on the south facing slope of a laterite plateau, in sandy soil, in the company of D. marchantii ssp prophylla, and also grew in deep sand, with D. gigantea. The golden green rosettes grew to 3 cm diameter and had up to 3 scapes.

Drosera macrantha ssp macrantha
Scattered plants of the climbing tuberous sundew, Drosera macrantha ssp macrantha ,were found growing  on laterite plateaus and also in deep sand. At the time of the visit the species had finished flowering and was starting to die down. This species was recognised by the relatively thick (2 – 3 mm diameter) stem, generally golden green colour, presence of glandular hairs on the upper part of the stem, including the inflorescence, and pedicels of the leaves, and circular, and down-facing leaves borne in threes, the central one of which had a long pedicel, to ca. 8cm long .

Drosera marchantii ssp prophylla
Scattered plants of the erect growing tuberous sundew, Drosera marchantii ssp. prophylla, were found growing on the flanks of laterite hills growing in a sand and laterite soil. The plants had finished flowering at the time of the visit, a few of which had already shed their seed. The golden green plants grew to ca. 25 cm tall, had a conspicuously inflated base which was covered by a numerous linear scale-like leaves, had few flowered inflorescences with flowers held on relatively long scapes, had leaves held singularly on the stem, and which often grew in small groups of up to 4 plants probably derived from natural division of the tuber.

Drosera menziesii ssp menziesii
A few plants of the slender climbing tuberous sundew, Drosera menziesii ssp. menziesii, were found near the creek on the property, and were also found in greater abundance in deep sand near Moore River. The plants were in flower at the time of the visit and had red, slender glabrous climbing stems to 30 cm tall. The round leaves were borne in threes up the stem and the pedicels were generally less than 2 cm long. The deep pink petalled flowers were fragrant and had hairy sepals.

Drosera menziesii ssp thysanosepala
A large number of the slender climbing tuberous sundew, Drosera menziesii ssp thysanosepala, were found growing in kwongan vegetation on the upper parts of laterite plateaus in sandy soil with ironstone. The plants were very red in colour, lacked hairs, except for the margins of the sepals, and had leaves in threes alternating up the stem. The pale pink flowers were open at the time of our visit, even under overcast conditions, were sweet smelling and almost circular in outline. I observed a hover fly visiting one flower, perhaps feeding on pollen, and which may act as a pollinator.

Drosera miniata
Abundant plants of the pygmy sundew, Drosera miniata, were found on the upper portions of the laterite plateaus. They grew in soil composed on ironstone with a variable content of sand, in the sandier soils they sometimes grew withD. enneaba. The flat rosettes grew to 1.5 cm diameter, which were often hard to see. The most conspicuous feature of this species were the open flowers, to ca. 8mm diameter, which had iridescent orange petals with dark red, almost black veins radiating out from the black ovary, the later was surmounted by three thread-like styles. The dark red coloured stamens were generally not a conspicuous feature of the open flowers.

Drosera miniata often grew with D. barbigera and the two were often flowering together. It was interesting to note that the flowers of both species were very similar in appearance and size – orange with a dark red centre, yet there were no signs of hybrids between these species.

Drosera pallida
A few plants of the climbing tuberous sundew, Drosera pallida, were found growing near the top of a some laterite hills. This species had finished flowering and was starting to die down at the time of out visit but was identified from the other climbing sundews by the following; glabrous stem, usually 2mm diameter, and sepals; general lime green colour of the plants and rounded, down facing lamina, borne in threes with pedicels often 2 to 4 cm long.

Drosera stolonifera ssp humilis
A few plants of the tuberous sundew, Drosera stolonifera ssp. humilis were found at the farm. They grew in sandy soil on the mid slope of a laterite hill and on flat ground near a creek. These many branched plants had stems to ca. 12 cm long and no signs of the remains of inflorescences. The whorled leaves had petioles which were circular in cross section and triangular lamina which the upper corners folded up towards each other. The slender stolon grew across the ground for up to 3cm after it had emerged from above the tuber.

stolonifera ssp porrecta
An abundance of the tuberous sundew, Drosera stolonifera sspporrecta grew on the property on the flanks and upper portions of the laterite hills. The plants emerged vertically above the tuber and immediately formed two rosettes of short petioled leaves. The plants varied in the amount of branching which occurred above the two basal rosettes. Plants produced between one and ca. five stems, which grew erect, up to 20 cm long. The mature leaves were borne in whorls , had a furrowed petiole and were triangular in outline with the upper corners folded back so that they were almost in contact and which resulted in an almost circular outline to the leafblade. Many of the branching plants had flowered, and had now shed most of their seed. The inflorescence emerged from the top of the upper basal rosette at the base of the branches. Most plants grew singularly although a few had divided once.

In addition to the carnivorous plants mentioned above flowering plants of  the erect tuberous sundew, Drosera microphylla  had been seen on laterite hills on the property in early winter. The plants had orange petals (M. Hislop, pers. Comm., 1995).

The area near Mt. Lesueuer has a remarkably diverse flora, as indicated by the range of carnivorous plants which were seen there. It is a botanist’s delight to spend time in the area.

Acknowledgements:

I wish to thank the Murdoch Branch of the Wildflower Society of Western Australia for the opportunity to be involved in this vegetation survey, and for the owners of the properties visited  for granting access.

Posted in Field Studies

Carnivorous Plant Encounter, Walpole, WA

Originally appeared in Flytrap News 10(4): 8-12, (1997)

Carnivorous Plant Encounter, Walpole, Western Australia

Robert Gibson

In late December 1996 I spent 3 days traveling around the south coast of Western Australia, observing 15 species of carnivorous plants in the wild whilst bushwalking. The plants seen, around Nannup, Northcliffe and Walpole, included many I have found elsewhere on the south coast as well as a few surprises; including Drosera binata, D. hamiltonii and Utricularia simplex. Following is account of the carnivorous plants encountered.

Cephalotus follicularis

The Albany Pitcher Plant was seen at two sedge swamps either side of Walpole. A third location, near Pemberton, was visited but was too overgrown to be deemed safe for exploration. At the sedge swamp west of Walpole the pitcher plants grew on the upper slope of the swamp, often at the foot, or the pedestals, of a distinctive, and robust species of Gahnia “grass”. This sedge has grey green leaves with coarsely serrated margins and smooth scapes, to 2.5m tall with flowers enclosed by a pair of large bracts. The height of vegetation in this swamp, which included many species of Myrtaceae, varied from 0.8 to 3m, and it appeared to have been burnt in the last few years.

Clumps of Cephalotus varied in appearance from fully green, with an equal production of pitchers and non-carnivorous leaves, to striking clumps of pitchers, to 5 cm tall, with abundant red pigmentation on the interior and exterior of the pitchers, in which the translucent “windows” on the lids appeared as vibrant white stripes. The contents of one pitcher examined consisted primarily of the recognisable remains of dark brown ants, to 6mm long, a species which lives in the sedge swamps. The remains of scapes were found of some clumps indicating flowering the previous summer.

At this site, in damp peaty soil, Cephalotus grew in the company non-flowering Drosera hamiltonii, D. binata and D. pallida. It was interesting that no pygmy Drosera nor Utricularia grew in this section of the swamp.

The second site, consisted of carbonaceous shale and sandstone cliffs at the back of a narrow beach, over which fresh water was constantly seeping. The pitcher plants grew on unstable slopes, the surface 30cm of which periodically slipped downslope leading to the death of all plants on board through desiccation or immersion in salt water. Many of the pitcher plants here were in scape, which grew to 60cm tall and varied in the level of flower development, although no flowers were open at the time. A well-formed rosette of non-carnivorous leaves precedes the emergence of a scape at a growing point.

The pitchers grew to 3cm tall and were generally brightly red pigmented in response to exposure to the sun. The contents of one old pitcher examined proved to be a soup of unrecognizable invertebrate body parts as well as 3 white, very healthy, living, worm-like dipteran larvae. The only variation observed in the plants at this site was the presence or absence of stipules on the lower third of the scape. At this coastal siteCephalotus grew with pink petalled plants of Drosera pulchella.

Drosera binata

Drosera binata was found on the edge of a sedge swamp near Broke Inlet, west of Walpole, growing with Cephalotus follicularis, D. hamiltonii and D. pallida. The plants had one to five olive green, erect, self-supporting petioles to 20cm tall and supported a singly forked lamina to 6 cm long. The lamina, with fully dark red retentive glands, captured small flies and midges and were projecting through into small openings amongst sedge and restio leaves. No plants were in scape or flower, but it appeared that the plants were reproducing asexually from the thick root system.

This species appears to be native to the area, it is neither dominant nor rare, and appears to be significantly far from major human disturbance and weeds. Given this species’ intolerance of submersion and prolonged desiccation only a few habitats appear suitable for it on the south coast of Western Australia. It grows in sandy peat, at the sloping edge of a sedge swamp, where it drains a low wooded ridge. At the time of my visit a thin dry crust had formed over the moist sandy peat in which the plants grew.

The presence of Drosera binata on the south coast is food for thought. Is it a relict form of the species which has subsequently spread east and prospered and diversified in areas of year-round humidity? The form of this species is very like the “t-form” which grows in Tasmania, and it would be interesting to see the flower and seed morphology of this Western Australian population in the first summer following the next bushfire in the swamp. It may be no coincidence that it grows with Cephalotus follicularis and Drosera hamiltonii, two taxonomically isolated and relict species.

D. dichrosepala

A small colony of D. dichrosepala was found beside a small creek near Northcliffe. The green open, semi erect rosettes, to 1.3cm diameter, grew in fine-grained white quartz sand in a small clearing in Jarrah woodland. Several plants had conspicuously hairless scapes developed, a few with small white petalled flowers open in the late afternoon. In this area the introduced Watsonia bulbillifera was becoming established and may out compete this, and the majority of small native plants.

D. hamiltonii

Three colonies of the attractive D. hamiltonii were seen on this visit. The first was on the edge of a drainage channel through a sedge swamp near Northcliffe. Vivid red rosettes, to 8cm diameter were seen in exposed areas, one of which had an erect scape, to 60 cm tall with 19 flowers, the second last of which had recently closed. More abundant, smaller, less intensely pigmented rosettes grew nearby, shaded by clumps of sedges and an array of fallen leaves. Several plants were wilting in response to drying soil, and would likely die down to the thick rootstock from which new rosettes would likely later sprout. Pink petalled plants of Drosera pulchella grew nearby, on disturbed soil at the roadside, and the bottom of the drainage channel was locally brightened by purple flowers of Utricularia dichotoma.

The two other sites were in coastal plain swamps west of Walpole. One site, with three plants with open pink flowers, was in disturbed swamp, where 30 rosettes, to 6cm across, nestled at the foot of a small manmade scape of peat beside a drainage pond. The plants grew in moist, but not sodden peaty sand, in a highly exposed area. They caught a few small flying insects and the dead leaves of small leaved shrubs of theMyrtaceae family. As with the above site the plants in the most open locations flower, perhaps as a response to the enhanced opportunity  for seedling establishment? Around these plants grew D. pulchella, D. roseana, D. menziesii ssp menziesii and U. multifida.

At the D. binata and Cephalotus swamp grew abundant rosettes of D. hamiltonii. Unlike the above sites  the rosettes were scattered and variably shaded and hidden by a well developed overstory of sedges, restios and shrubs. No plants were in flower and the rosettes were generally 3 to 6 cm across.

D. menziesii ssp menziesii

Dieing scrambling stems of D. menziesii ssp menziesii were found in two habitats – in coastal plain swamplands and in thin, moss-covered soil of granite outcrops in Jarrah and Karri forest; habitats with seasonally extreme changes in soil moisture levels. The stems grew to 30cm tall, many of which had the remains of inflorescences. In rare cases some leaves were still alive and bedewed. In the coastal plain swamps this species grew with D. pulchella, sometimes with D. roseana, D. pallida and D. stolonifera ssp compacta and U. multifida. On the granite outcrops it often grew with U. multifida.

D. neesii ssp neesii

Rare plants of D. neessi ssp neesii were found in recently burnt coastal plain north of Windy Harbour. The plants grew to 15 cm tall,  were shedding seed and were all but fully dormant. The plants grew in the company of D. pulchella in dry surfaced peaty sand.

D. occidentalis ssp australis

Scattered plants of diminutive rosettes, to 1cm across, with round red lamina on thin petioles, were found in coastal plain swamps and lake margins between Windy Harbour and Walpole. Solitary flowered short scapes, to 2cm tall were seen on a few plants but no open flowers were seen which may have revealed that some of the plants could have instead been the very similar D. pygmaea.

D. pallida/ D. erythrogyna

Dieing scrambling, non-flowering stems of either D. pallida or D. erythrogyna, or perhaps both were found in a few sedge swamps between Northcliffe and Walpole. Plants were found in the company of Cephalotus follicularis and D. hamiltonii, which had lamina with fully circular outline, which indicates they may be D. pallida. The plants were almost fully dormant and few were still bedewed.

D. platystigma

Golden green rosettes, to 2 cm diameter of Drosera platystigma were found growing in disturbed moist sandy soil beside the road south of Nannup. Initially I thought I had found a colony of D. pulchella on account of the wide petiole and rounded lamina of the flat rosettes. Many plants were in scape, three of which were found to have open flowers during my mid-morning visit. The orange petalled flowers were 6mm across, each petal had a dark orange base from which extended a few veins into the bulk of the petal; and are very like the form illustrated in Kondo and Kondo (1983) on page 61. It was not until I examined the structure of the dark orange styles that I recognized this species

D. pulchella

Abundant golden green rosettes of D. pulchella were seen in most damp locations between Northcliffe and Albany. Two forms of the species were seen, those with pink petals; which appear to be the most widespread pygmy Drosera in Western Australia, and those with orange petals. It has been suggested that the pink petal form is more common in the lower lying ground whilst the orange-petalled form favours higher ground, often in laterite-derived soils. My observations were contrary to these but this may reflect mixing of the forms due to human disturbance of the land.

D. roseana

Attractive, semi-erect rosettes of D. roseana were found in coastal plain swamps between Northcliffe and Walpole, often in the company of D. pulchella, D. occidentalis ssp australis/ D. pygmaea and U. simplex. Plants, to 1.8 cm diameter, had elongated red lamina on narrow green petioles, were in scape, with many small white petalled flowers open at the time of my visit, although the flowers were observed to open primarily under sunny conditions. The distinctly hairy scapes and sepals are characteristic of this species.

D. stolonifera ssp compacta

A single colony of D. stolonifera ssp compacta was found in a sedge swamp east of Northcliffe. The stems, to 12 cm tall, were pale brown and almost fully withered but still bore the large, paddle shaped leaves born in whorls. No sign of scapes were seen.

Utricularia dichotoma

Attractive flowering clumps of U. dichotoma were seen beside creeks and in drains in Jarrah woodland near Northcliffe. The plants had scapes to 20cm tall bearing a pair of opposite flowers. The flowers had triangular lower lips, to 1.3 cm across by 1 cm long, the free rounded corners of which were curved gently down. The palate consisted of two raised yellow ribs edged by dark purple, and is partially overhung by the wedge-shaped upper lip. The lower lip was lilac in colour save for one small colony where it was same very pale purple of the upper lip in all plants seen. This bicoloured form of the species is most attractive. The spoon shaped dark green leaves often grew under a film of algae-stained water.

This highly localized species grew near Drosera pulchella and D. hamiltoniiand is also known from south eastern Australia.

U. simplex

Diminutive clumps of U. simplex were seen in coastal plain near Windy Harbour, and were recognized initially from the comparatively large open flower on a few scapes. The purple flowers have a bluntly triangular lower lip, from under which the end of the horizontal spur projects. A vertical wedge-shaped lower lip rises above the palate of the lower lip which is marked by a touch of pale yellow pigmentation. The solitary flowers, to 6mm across and high, are held on the end of dark purple scapes, to 3cm tall. The narrow dark green linear leaves, to 4mm long by 0.7 mm wide, are often hidden by fallen leaves and algae.

This species grew in moist peaty sand in the company of D. pulchella, D. occidentalis ssp australis/ D. pygmaea and D. roseana, and is closely related to U. lateriflora and U. delicatula which are native to south eastern Australia and New Zealand respectively (Taylor, 1989).

U. multifida

Bright pink flowers of the widespread and delightful U. multifida were seen in roadside gutters, coastal plain swamps and on granite outcrops from Northcliffe to Denmark. Whilst the peak flowering period had finished, and many flowers had now withered and the fine seed shed, many plants in the colonies had produced a second or third scape which were still growing into early summer. The scapes, to 15cm tall, had up to 7 flowers. These supported attractive clear pink, or white in one location, with a three lobed lower lip and bifurcated upper lip with a palate of three to five sulphur yellow ridges in between. One aphid attacked plant had an unusual double flower in which the two incomplete flowers were joined along a line down the centre. This bladderwort was frequently found in the company of D. pulchella.

This section of the coastline is dominated by kwongan (“heath”) covered coastal plains with lakes, swamps and few sizable perennial streams. The undulating hinterland consists of low granitic outcrops, with a variable amount of the laterite (a weathering product) preserved; and upon which the magnificent Jarrah and Karri forests grow. A few scattered granitic, forest clad hills occur close to the coast where they occur as vegetation islands surrounded by extensive swampy coastal plain. The geomorphology of the coast suggests that the sluggish streams, and all but the large rivulets, have been dammed by extensive coastal sand dunes at the backs of beaches. Sand, peat and clay accumulate in the basins behind the dunes whilst the water seeps through to the ocean. Under the present climate, with winter maximum rainfall, and summer drought, soil on granite and laterite outcrops and a large area of the coastal plain vary enormously in water content throughout the year. Only the soil in the center of the larger swamps, beds of the larger streams, and any larger lakes remain wet all year round. With the large variation in habitats, soil types and seasonal water table levels it is perhaps not surprising that so many species have evolved in the south west of Western Australia.

When walking through the swamps it is apparent that it is home to many animal species as well. The most conspicuous are the invertebrates, of which flies, mosquitoes, other Dipterans, ants and spiders are the most frequently encountered. Along the south coast of Western Australia are species of black, moderately ornamented colonial spiders which spin strong but not sticky webs between the majority of shrubs and tall herbs. Snakes are common residents of sedge swamps too, many species of which are venomous. When venturing into such habitats I recommend wearing long trousers, sturdy shoes, a hat and either a long sleeved or short sleeved shirt. The spiders are harmless but few people are comfortable with them and their webs over their skin. As for the snakes; they generally keep out of your way so make lots of noise, move slowly and watch where you put your feet. Remember that we are guests in these environments.

The few days spent traveling leisurely around this section of the Western Australian south coast were very enjoyable, relaxing and rewarding. It was a pleasure to get a feel for the nature of this section of the coast and how a selection of carnivorous flora fits in there. The observations have been sumptuous food for thought particularly about the history and ecology of apparently ancient species such as Cephalotus follicularis, Drosera hamiltonii and D. binata.

REFERENCES

Kondo and Kondo, 1983. Carnivorous Plants of  the World in Colour. Ienohikari Association, Tokyo.

Taylor, P. 1989. The Genus Utricularia: A Taxonomic Monograph. Her Majesty’s Stationery Office, London.

Posted in Field Studies

World’s Largest Drosera

The world’s largest Drosera
CPN Volume 30, No 3, 79

In September of 1999 whilst showing the world renown Drosera expert Robert Gibson and keen CP photographer Tuan Nguyen, through some selected sites of the South Coast of Western Australia, we came across a plant of Drosera erythrogyna growing up the burnt remains of a Banksia quercifolia. A fire had burnt this Cephalotus swamp the previous year leaving only the dead trees standing. Taking the opportunity of the very open growth for a change, this plant of Drosera erythrogyna had climbed to a height of over 10 feet (3.1m). The single stem had branched about twelve times and we estimated that there were over 1,000 leaves and 400 flowers on this plant.

Below is a photograph of this plant with Robert Gibson indicating the height.

image002

Posted in Field Studies

Laterite and General Notes on the Soil

The southwest of Western Australia is world famous for its wealth of endemic plant species, including an abundance of carnivorous plants. When viewed by those used to seeing Drosera and Utricularia confined to wet peaty soil of the temperate Northern Hemisphere the abundance and widespread distribution of the native carnivores is at first puzzling. Whilst peat bogs do occur in this region, they are of very limited extent. The majority of carnivorous plant habitats occur in seasonally moist to saturated soil which is composed largely of laterite or sand. In the following article the basic soil components in this botanic wonderland are described. As will be revealed it could be argued that the soil composition may have played a large role in the evolution of such a floral paradise.

There are five basic components of the soils in southwestern Australia: duricrust, clay, sand, rock fragments and organic matter. The combination of these in any one area is determined by the geological history, drainage and climate of the area. Over a short distance the soil composition and profile can change rapidly. There may be scarcely perceptible changes in slope, surface drainage or climate over this distance but there will probably be a dramatic change in plant species composition. The geology of this area has also been an important factor in the resultant soils. The most abundant rocks are granites and gneisses, which are rich in the minerals quartz and feldspar. Quartz is physically durable and generally chemically inert, whereas feldspars are slightly softer and weather readily to form clays. Linear belts of “greenstone” also occur, which are composed of iron-rich minerals.

Duricrust is probably the most well known element of the soil in this part of the World. It is a conspicuous surfacial layer formed by laterite weathering, and is sometimes itself called “laterite”. Lateritic weathering is an intense chemical breakdown and produces a very distinctive layered profile, and which is tied with the activity of ground water movement (Figure 1). Initially oxygen-rich rainwater filters through the soil and decaying rock, and under warm, seasonally humid conditions is able to dissolve most minerals. In doing so the level of oxygen decreases, affecting the solubility of some dissolved compounds, particularly iron oxides.

In surficial environments iron is generally oxidised to the insoluble ferric (+3) state, however, in oxygen-poor conditions it changes to the water-soluble ferrous (+2) state during which it is readily transported in ground water. Where iron-rich rocks are present around the granite plutons of this region, and insoluble iron oxide and hydroxide chemical lag may form. In other cases all surficial and near-surface iron is dissolved, and eventually reprecipitated where the ground water reaches the surface and a higher oxygen concentration. The duricrust, or ferricrete, forms, and which is highly resistant to physical weathering. It may be massive or granular in texture, the later are known as “pisolites”, and often includes oxides and hydroxides of aluminium (White, 1994). In this chemical environment quartz and calcite may also be precipitated just below the oils surface and form “silcrete” and “calcrete” respectively.

Where the oxygen-poor ground water moves through the decaying rock it removes all but insoluble clay, which forms a layer known as “saprolite”. At depth, relict original rock textures are still retained forming a basal layer of “saprock”. This is adjacent to the top of the fresh rock, which may be tens of metres below the surface. In general lateritic weathering represents a significant volume reduction of rock. It appears to be a fossil. It appears that laterite weathering throughout southwestern Australia is a fossil feature which was produced when the region experienced a monsoonal climate; this changed relatively recently, within the last 4 million years to the present Mediterranean climate.

With a change in climate and a reduction, or cessation, of lateritic weathering this distinctive soil and rock profile has been progressively dissected (Figure 2). Once the hard duricrust cap has been breached physical erosion of the clay zone occurred rapidly, and eventually fresh rock was exposed. During lateritic weathering the majority of minerals in granites and gneisses were dissolved, including quartz. However, with a change in weathering regime the layers of the lateritic weathering profile were locally stripped away revealing fresh rock. This began to break down but, this time, it yielded rock fragments, clay and quartz sand. The various mineral components: duricrust, clay, rock fragments and quartz sand were variably transported, deposited and concentrated throughout the landscape producing complex soil profiles.

Plant matter is another important soil component which is produced in most abundance, and accumulates most quickly along drainage lines, in swamps, and in creek and river beds. The locally produced peat is composed primarily of the remains of sedges, small mosses and other wetland plant species. It is worth noting that whilst sphagnum moss does occur in Western Australia, it is only recorded from two small sites on the extreme south coast and is thus not a significant peat-forming species.

The nutrient value of most of the soil components within this region is very low. Lateritic duricrust has been intensely weathered and all soluble minerals have been removed. Quartz sand is intrinsically inert. Peat in the wetlands comprises a store of plant nutrients which are locked up until slow decay or fire releases them. Due to the mineralogy of the underlying granites and gneisses, even the more mineral-rich clays and rock fragments are still poor in many essential plant nutrients.

The physical properties of the soil components plays an important role in producing a variable soil terrain. The lateritic duricrust, where coherent, generally forms a barrier to water movement, which is then concentrated in cracks and clefts. In contrast a layer of pisolites is highly porous and acts as a mineral mulch. Quartz sand is also highly porous and, where it occurs above impervious fresh rock, clay or coherent lateritic duricrust, it may hold significant volumes of water. Similarly peat accumulations act like a sponge in storing water. Fresh granite and gneiss are generally impervious, forming large rounded outcrops, however, water may be stored with fractures and along geological contacts, and is often temporarily stored with the surface layer of mosses and herbs where they are established. Clay rich soils often have good water storage ability, and may become seasonally waterlogged where hard pans are developed. During the seasonal summer drought the soil is exposed to intense solar radiation. Due to the low thermal conductivity of quartz sand, lateritic duricrust, and dry peat the soil surface may become extremely hot (over 50°C) whilst the a few centimetres down soil conditions are cool and humid.

The scene is now set to look at a few factors in the carnivorous plant diversity in southwestern Western Australia. In general soils are nutrient poor, with variable water holding ability, but winter rainfall and the air temperature during the coolest 6 months of the year are conducive to plant growth. As a general rule it is now thought that where nutrient-poor soils are developed no single species is able to dominate the landscape, instead co-dominance is the rule, with many species growing together in a small area. This is also well developed in such places as the Cape Province of South Africa and the sandstone plateaux of southeastern Brazil. Even with the advent of the carnivorous syndrome, this small, but most interesting group of plants has not been able take up the role as the dominant plant group. At least not yet.

Throughout southwestern Western Australia the carnivorous plant flora has evolved and spread into the most environments; an achievement helped greatly by the development of survival mechanisms for the seasonal summer drought. The two main groups ofDrosera survive the summer by retreating to tubers safely below the scorching heat, or in the heat-resistant stipule buds of pygmy sundews. Most Utricularia and sundews also survive as seeds which lodge in cracks in the soil. Byblis gigantea survives as swollen roots deep within the soil. In general, the native carnivorous plants occur in great diversity and abundance in a great range of different environments.

Each of the main soil types is utilised by a range of carnivorous plants; a few examples are now given. The coherent lateritic duricrust is home to such species as D. barbigera, D. miniata, D. stolonifera ssp. porrecta. Pisolitic laterite soil supports D. hyperostigma, D. erythrorhiza ssp magna, D. erythrorhiza ssp squamosa, D. erythrorhiza ssp “Roleystone Red”, D. stolonifera ssp porrecta. Thin quartz sand over coherent laterite supports the northern population of Byblis gigantea. : Drosera macrophylla is a great coloniser of exposed saprolite. Clefts in fresh exposed granite and gneiss are home to D. macranthassp macrantha, D. menziesii ssp menziesii, Utricularia menziesii and D. browniana. Accumulations of rock fragments supports D. microphila (around Esperance), D. scorpiodes and D. macrantha ssp macrantha. Deep quartz sand is the preferred soil ofD. zonaria, D. erythrorhiza ssp erythrorhiza, D. stolonifera ssp humilis D. enneaba andD. paleacea ssp paleacea. Seasonally wet peaty sand is the preferred habitat for D. rosulata, D. helodes, D. nitidula ssp nitidula and the southern population of Byblis gigantea. Permanently to seasonally wet peat is the preferred medium for Cephalotus follicularis, Utricularia volubilis, D. hamiltonii, D. binata, D. pulchella, D. gigantea, D. stolonifera ssp monticola and D. neesii ssp neesii. This list is incomplete and many of the native carnivorous plant species grow in several different soil combinations.

The five soil components: lateritic duricrust, clay, rock fragments, quartz sand and organic matter within southwestern Western Australia have formed together under differing conditions, some of which are no longer active. They now occur as a complex mosaic, with highly variable physical conditions, but similar low nutrient status, which supports an incredible diversity of plants which exist in co-dominance. This also applies to the native carnivorous plant flora. It is hoped that this outline will assist in knowledge of the position of these plants in the wild and in their successful cultivation.

Reference:

White, M. E. 1994. After the Greening: the Browning of Australia. Kangaroo Press, Sydney.

Figure Captions:

lat1

Figure 1: Active Tertiary laterite weathering profile over granite. Strong chemical leaching, from oxygenated ground water dissolves  the majority of rock-forming minerals as it passes through a layer of decaying rock. Clay-rich saprolite is left behind. Insoluble iron oxide-rich duricrust forms an insoluble chemical lag (shown by diagonal lines and circles), and may also be precipitated in accumulated sediment when the ground water reach the sediment. Arrows indicate the general movement of ground water. At depth, fresh rock occurs (indicated by crosses).

lat2

Figure 2: After a change in climate, physical weathering dominated over nominal chemical changes. Laterite weathering ceases, and its profile is dissected. this leads to highly diverse soil profile changes where fresh rock, duricrust, saprolite and saprock and variable exposed and covered by a mixture of their own fragmented residue. In addition, wind and water-sorted quartz sand (stippled) and peat accumulations (shown in black) may locally occur. Carnivorous plants have evolved to fill niches in almost all of these soil types.

Posted in Field Studies

CP of WA Seasonal Chart

Many thanks to Robert Gibson and Phill Mann for providing this Carnivorous Plant Chart showing the seasonal growth patterns of the Western Australian species. Click HERE to view the Chart.

Posted in Field Studies

CPWA Seasonal Growth Chart

Carnivorous Plants of Western Australia
Seasonal Growth Chart
TAXON /POPULATIONJANUARYFEBRUARYMARCHAPRILMAYJUNEJULYAUGUSTSEPTEMBEROCTOBERNOVEMBERDECEMBERBroad DistributionWithin 100 km of Perth?Growth Form
D. andersoniana    South WestNoTuberous – Erect
D. bicolor    South WestNoTuberous – Erect
D. bulbigena    South WestYesTuberous – Erect
D. erythrogyne    South WestNoTuberous – Climbing
D. gigantea ssp. gigantea   South WestYesTuberous – Erect
D. giganteassp. geniculata    South WestYesTuberous – Erect
D. graniticola    South WestNoTuberous – Erect
D. heterophylla    South WestYesTuberous – Erect
D. huegelii    South WestNoTuberous – Erect
D. intricata    South WestYesTuberous – Climbing
D. macrantha ssp. macrantha    South West, DesertYesTuberous – Climbing
D. macrantha ssp. eremaea    DesertNoTuberous – Erect
D. marchantii ssp. marchantii    South WestNoTuberous – Erect
D. marchantii ssp. prophylla    South WestNoTuberous – Erect
D. menziesii ssp. menziesii    South WestYesTuberous – Climbing
D. menziesii ssp. basifolia    South WestNoTuberous – Erect
D. menziesii ssp. penicillaris    South WestYesTuberous – Climbing
D. menziesii ssp. thysanosepala    South WestNoTuberous – Climbing
D. microphylla    South WestNoTuberous – Erect
D. modesta    South WestNoTuberous – Erect
D. moorei    South WestNoTuberous – Climbing
D. myriantha   South WestNoTuberous – Erect
D. neesii ssp. neesii   South WestNoTuberous – Erect
D. neesii ssp. borealis    South WestNoTuberous – Erect
D. pallida    South WestYesTuberous – Climbing
D. peltata "W.A. Form"    South WestNoTuberous – Erect
D. radicans    South WestNoTuberous – Erect
D. salina    South WestNoTuberous – Erect
D. stricticaulis    South WestYesTuberous – Erect
D. subhirtella    South WestNoTuberous – Climbing
D. sulphurea   South WestNoTuberous – Erect
D. zigzagia    South WestNoTuberous – Rosetted
TAXON /POPULATIONJANUARYFEBRUARYMARCHAPRILMAYJUNEJULYAUGUSTSEPTEMBEROCTOBERNOVEMBERDECEMBERBroad DistributionWithin 100 km of Perth?Growth Form
D. browniana    South WestNoTuberous – Rosetted
D. bulbosa ssp. bulbosa     South WestYesTuberous – Rosetted
D. bulbosa ssp. major    South West, DesertNoTuberous – Rosetted
D. erythrorhiza ssp. erythrorhiza    South WestYesTuberous – Rosetted
D. erythrorhiza ssp. collina    South WestYesTuberous – Rosetted
D. erythrorhiza ssp. magna    South WestNoTuberous – Rosetted
D. erythrorhiza ssp. squamosa    South WestYesTuberous – Rosetted
D. lowriei     South WestNoTuberous – Rosetted
D. macrophylla ssp. macrophylla    South WestNoTuberous – Rosetted
D. macrophylla ssp. monantha     South WestNoTuberous – Rosetted
D. orbiculata    South WestNoTuberous – Rosetted
D. prostratoscaposa    South WestNoTuberous – Rosetted
D. rosulata    South WestYesTuberous – Rosetted
D. tubaestylus    South WestYesTuberous – Rosetted
D. zonaria    South WestYesTuberous – Rosetted
D. fimbriata    South WestNoTuberous -Fan Leaved
D. platypoda    South WestNoTuberous -Fan Leaved
D. ramellosa     South WestYesTuberous -Fan Leaved
D. stolonifera ssp. stolonifera     South WestYesTuberous -Fan Leaved
D. stolonifera ssp. compacta     South WestNoTuberous -Fan Leaved
D. stolonifera spp. humilis     South WestNoTuberous -Fan Leaved
D. stolonifera ssp. monticola    South WestNoTuberous -Fan Leaved
D. stolonifera ssp. porrecta     South WestYesTuberous -Fan Leaved
D. stolonifera ssp. prostrata     South WestNoTuberous -Fan Leaved
D. stolonifera ssp. rupicola     South WestNoTuberous -Fan Leaved
 
D. androsacea    South WestNoPygmy
D. barbigera     South WestYesPygmy
D. callistos    South WestYesPygmy
D. citrina    South WestNoPygmy
D. closterostigma    South WestYesPygmy
D. dichrosepala     South WestNoPygmy
TAXON /POPULATIONJANUARYFEBRUARYMARCHAPRILMAYJUNEJULYAUGUSTSEPTEMBEROCTOBERNOVEMBERDECEMBERBroad DistributionWithin 100 km of Perth?Growth Form
D. echinoblastus    South WestYesPygmy
D. eneabba    South WestNoPygmy
D. enodes    South WestNoPygmy
D. ericksoniae   South WestYesPygmy
D. grievei    South WestNoPygmy
D. helodes    South WestYesPygmy
D. hyperostigma    South WestYesPygmy
D. lasiantha   South WestNoPygmy
D. leioblastus   South WestNoPygmy
D. leucoblastus    South WestNoPygmy
D. manniana   South WestYesPygmy
D. miniata     South WestYesPygmy
D. nitidula ssp. nitidula   South WestYesPygmy
D. nitidula ssp. allantostigma   South WestYesPygmy
D. nitidula ssp. leucostigma   South WestYesPygmy
D. nitidula ssp. omissa   South WestYesPygmy
D. nitidula ssp. nitidula x D. ericksoniae  South WestYesPygmy
D. nitidula ssp. allantostigma x D. ericksoniae  South WestYesPygmy
D. nitidula ssp. omissa x D. pulchella   South WestYesPygmy
D. nitidulassp. omissa x D. occidentalis ssp. occidentalis   South WestYesPygmy
D. nivea    South WestNoPygmy
D. occidentalis ssp. occidentalis   South WestYesPygmy
D. occidentalis ssp. australis   South WestNoPygmy
D. oreopodion    South WestYesPygmy
D. paleacea ssp. paleacea    South WestYesPygmy
D. paleacea ssp. trichocaulis    South WestNoPygmy
D. parvula   South WestYesPygmy
D. platystigma   South WestYesPygmy
D. pulchella   South WestYesPygmy
D. pynoblasta   South WestNoPygmy
D. pygmaea – "Western Australian Form"   South WestNoPygmy
D. roseana    South WestNoPygmy
D. sargentii   South WestNoPygmy
D. scorpiodes    South WestYesPygmy
D. sewlliae    South WestYesPygmy
D. stelliflora   South WestNoPygmy
D. silvicola    South WestNoPygmy
D. spilos    South WestYesPygmy
D. Walyunga    South WestYesPygmy
TAXON /POPULATIONJANUARYFEBRUARYMARCHAPRILMAYJUNEJULYAUGUSTSEPTEMBEROCTOBERNOVEMBERDECEMBERBroad DistributionWithin 100 km of Perth?Growth Form
D. binata (WA)    South WestNoPerennial
D. burmanni (WA)    Tropical, DesertNoAnnual
D. glanduligera   South WestYesAnnual
D. hamiltonii   South WestNoPerennial
D. hartmeyerorum    TropicalNoAnnual
D. indica – narrow leaf, white or pink flowers    TropicalNoAnnual
D. indica – ‘hooded red stamens’    TropicalNoAnnual
D. indica – orange flowers    TropicalNoAnnual
D. indica – wide leaf form    Tropical, DesertNoAnnual
  
D. banksii    TropicalNoAnnual
D. broomensis    TropicalNoPerennial
D. caduca   TropicalNoPerennial
D. derbyensis    TropicalNoPerennial
D. dilatatopetiolaris    TropicalNoPerennial
D. kenneallyi   TropicalNoPerennial
D. ordensis    TropicalNoPerennial
D. paradoxa     TropicalNoPerennial
D. petiolaris   TropicalNoPerennial
D. subtilis    TropicalNoAnnual
 
Aldrovanda vesiculosa (Kimberely Region)     TropicalNoPerennial
Aldrovanda vesiculosa (Esperance Region)     South WestNoPerennial
 
Cephalotus follicularis  South WestNoPerennial
 
TAXON /POPULATIONJANUARYFEBRUARYMARCHAPRILMAYJUNEJULYAUGUSTSEPTEMBEROCTOBERNOVEMBERDECEMBERBroad DistributionWithin 100 km of Perth?Growth Form
Byblis gigantha (Perth Region)    South WestYesPerennial
Byblis gigantha (Northern Sandplains)    South WestNoPerennial
Byblis filifolia    Tropical, DesertNoAnnual
Byblis linifolia    TropicalNoAnnual
Byblis roridula   TropicalNoAnnual
 
Utricularia aurea   TropicalNoAquatic – Perennial
Utricularia aurea x U. meulleri[putative hybrid]   TropicalNoAquatic – Perennial
Utricularia australis     South WestNoAquatic – Perennial
Utricularia gibba   Tropical, South WestYesAquatic – Perennial
Utricularia muellerii   TropicalNoAquatic – Perennial
Utricularia stellaris   TropicalNoAquatic – Perennial
Utricularia tubulata   TropicalNoAquatic – Perennial
Utricularia antennifera    TropicalNoTerrestrial – Annual
Utricularia benthamii    South WestNoTerrestrial – Annual
Utricularia bifida   TropicalNoTerrestrial – Perennial
Utricularia caurelea   TropicalNoTerrestrial – Perennial
Utricularia chrysantha   TropicalNoTerrestrial – Annual
Utricularia dichotoma (WA)   South WestYesTerrestrial – Perennial
Utricularia dunlopii    TropicalNoTerrestrial – Annual
Utricularia dustaniae    TropicalNoTerrestrial – Annual
Utricularia fistulosa   TropicalNoAffixed aquatic – Perennial
Utricularia georgei     TropicalNoTerrestrial – Annual
Utricularia helix  South WestNoAffixed aquatic – Perennial
Utricularia inaequalis   South WestYesTerrestrial – Annual
Utricularia kenneallyi    TropicalNoTerrestrial – Annual
Utricularia kimberleyensis  TropicalNoTerrestrial – Perennial
Utricularia lasiocaulis   TropicalNoTerrestrial – Annual
Utricularia leptoplectra   TropicalNoTerrestrial – Perennial
Utricularia leptorhyncha    TropicalNoTerrestrial – Annual
Utricularia limosa   TropicalNoTerrestrial – Perennial
Utricularia menziesii    South WestYesTuberous – Perennial
Utricularia minutissima    TropicalNoTerrestrial – Annual
Utricularia multifida    South WestYesTerrestrial – Annual
Utricularia paulinae   South WestNoTerrestrial – Perennial
Utricularia petertaylorii   South WestYesTerrestrial – Annual
Utricularia quinquedentata    TropicalNoTerrestrial – Annual
Utricularia simplex   South WestNoTerrestrial – Perennial
Utricularia singeriana    TropicalNoTerrestrial – Annual
Utricularia tenella    South WestYesTerrestrial – Annual
Utricularia tridactyla    TropicalNoTerrestrial – Annual
Utricularia uliginosa   TropicalNoTerrestrial – Perennial
Utricularia violacea   South WestYesTerrestrial – Annual
Utricularia volubilis  South WestYesAffixed aquatic – Perennial
Utricularia westonii   South WestNoTerrestrial – Annual
 
168 taxa 
Legend :No Colour/White : No Above Ground GrowthGreen : Above Ground Growth; No FlowersBeige : White with Pink/White FlowersAll other colours show the approximate colour of the Flowers
OrangeYellowPinkPurpleRedPale Pink
References:
Gibson, R. (2000). LateSpring Travels in south western Western Australia. Bulletinof the Australian Carnivorous Plant Society, Inc. 19(4): 7-14.
Gibson, R. (1998). CarnivorousPlants near Mt. Lesueur, Western Australia. Carnivorous Plant Newsletter.(27): 81-84.
Gibson, R.; Gassin, R.;Howell, F.; Spence, S. and Denton, B. (1992). Field Notes of an Expedition toWestern Australia. Bulletin of the Australian CarnivorousPlant Society, Inc. 11(4): 13-17.
Lowrie, A. (1996) New speciesin Drosera section Lasiocephala (Droseraceae) from tropicalnorthern Australia. Nuytsia (11): 55-69.
Lowrie,A. (1987). Carnivorous Plants of Australia: Volume 1. UWAP
Lowrie,A. (1989). Carnivorous Plants of Australia: Volume 2. UWAP
Lowrie,A. (1998). Carnivorous Plants of Australia: Volume 3. UWAP
Lowrie,A. (1999). Some insights into the Australian perennial tropical Drosera.Bulletin of the Australian Carnivorous Plant Society, Inc. (18):12-20.
Lowrie, A.(2002). Utricularia petertaylorii:a new species from the south-west of Western Australia. Nuytsia (14): 405-410.
Schlauer,J. (2002). Drosera hartmeyerorumspec. nov. (Droseraceae), a new sundew in Sect. Arachnopus from NorthernAustralia. Carnivorous Plant Newsletter (30): 104-106.
Taylor,P. (1989). Kew Bulletin Additional Series XIV, The Genus Utricularia – a taxonomic monograph. HMSO, London.
Posted in Charts

Carnivorous Plants near Mt. Lesueur, WA

Originally appeared in Carnivorous Plant Newsletter, 1998, 27:3, p81-84. ISSN #0190-9215

Carnivorous Plants near Mt. Lesueuer, Western Australia

On the weekend of September 16 and 17, 1995, I had the pleasure in participating in a vegetation survey on a farm near Mt. Lesueur, approximately 250 km north of Perth.  During this survey a number of carnivorous plants were found, 13 species of Drosera and Byblis gigantea, which are described below.

Byblis gigantea

Byblis gigantea was found in two sites on the farm, both of which were on hill-slopes growing in a soil derived from fine, possibly windblown, quartz  sand and fragments of massive lateritic ironstone. The plants were found on disturbed ground, along firebreaks, and would have undoubtedly have occurred in the adjacent undisturbed low heathy vegetation known as ‘kwongan’.

At least ten mature plants were found at each site, and were in active growth, some of which had commenced flowering. The plants grew to 30cm tall, had one to three stems each, with erect linear leaves to 22cm long. At the lower part of the stem the leavers were close together, with 1 to 3 mm internodes. The more recent growth had internodes 1 to 2 cm apart and single, auxiliary flowers, the latter though were not present in the lowest 2cm of more rapid stem elongation. The pedicels were just shorter than the leaves and held a single, outfacing iridescent purple petalled flowers to 3cm diameter. A single seedling, with leaves to 5cm long and a poorly developed stem was found at one site.

The plants were fully bedewed and had caught a range of flying insects, including aphids, midges and a smaller number of bush flies. Most plants had at least two lime-green Drosera bugs on them which moved readily over the bedewed plants. No insects were seen visiting the open flowers.

These plants are part of the northern population of this species which differs from plants around Perth. These plants are generally smaller; have shorter leaves; grow in well drained soil on hillslopes; produce stems with less branching and fewer  plants from the root-system of established plants and had petals of the same colour throughout. They differ in choice of habitat form the southern population which prefer to grow in deep sand on the edge of swamps, and in the flower colour which includes a flattened, darker purple base on the inside of each petal

Drosera barbigera

Large numbers of the attractive and robust pygmy sundew, Drosera barbigera, were seen on the top and flanks of one of the laterite hills on the property. The plants grew in ironstone soil, with variable amounts of sand, often in colonies of a few tens to hundreds of plants.  The semi-erect rosettes grew to 3cm diameter, on the end of often-prostrate stems to 5cm long.  Many plants were in flower, with one to two scapes each., These grew to 10 cm long and had a tight cluster of flowers with conspicuously hairy sepals. The vibrant orange petalled flowers, to 1cm diameter, were open under sunny conditions, or when in the protection of adjacent low shrubs under cloudy conditions. The petals had a dark red base which was adjacent to the similarly colored ovary and its three threadlike styles. The anthers produced pale yellow pollen which stood out against this dark colored zone. A brown beetle was seen visiting one flower and may act as a pollinator.

Drosera enneaba

Large colonies of the pygmy sundew, Drosera enneaba, grew in sandy soil on the flanks of laterite plateaus. The glistening rosettes, to 2cm diameter, were seen in abundance on the fire trails. The orbicular red tentacled lamina occurred on the end of straight-sided petioles and formed a flat rosette. Many plants were in flower and had one, rarely two scapes , to 15 cm tall. The sweetly scented flowers had all white-petals, save for the distinct red dot near the ovary

Drosera erythrorhiza ssp ?magna

Scattered colonies of closely spaced rosettes of a taxon of the tuberous sundew, Drosera erythrorhiza, were seen throughout the farm in areas of deep sand, and on the edge and top of laterite plateaus. The rosettes were generally very red, with up to 8 leaves and were up to 8cm diameter, although most were smaller. Some plants were still bedewed although many were now starting to die down. A few still had the remains of scapes, which had already shed their seed. From the number of leaves and the size of the plants they were tentatively ascribed to subspecies magna, although some colonies could have been subspecies erythrorhiza. The close spaced colonies of these plants indicates either that some asexual reproduction occurs or the seed generally does not travel far from the parent plant. The identity of this taxon could be confirmed by looking at the root system and in checking the timing of flowering with respect to maturation of the rosette. Whatever its identity it is a large and beautiful variant in leaf.

Drosera gigantea

Scattered plants of the erect growing tuberous Drosera giganteawere seen in two locations in the area. One was in a creek bed, in water to 10 cm deep, and adjacent parts of the bank where plants to 40cm tall were seen. These were in bud, with many branches, few of which had mature leaves. The second site was in deep sand several hundred metres from the nearest creek bed. Some of these plants were already in flower although many had started to go dormant with the shrivelled remains of aborted inflorescences. At the second site a few plants had deep red stems.

Drosera glanduligera

Flowering rosettes of the annual Drosera glanduligera were found in the area. They grew  on the south facing slope of a laterite plateau, in sandy soil, in the company of D. marchantii ssp prophylla, and also grew in deep sand, with D. gigantea. The golden green rosettes grew to 3 cm diameter and had up to 3 scapes.

Drosera macrantha ssp macrantha

Scattered plants of the climbing tuberous sundew, Drosera macrantha ssp macrantha ,were found growing  on laterite plateaus and also in deep sand. At the time of the visit the species had finished flowering and was starting to die down. This species was recognised by the relatively thick (2 – 3 mm diameter) stem, generally golden green colour, presence of glandular hairs on the upper part of the stem, including the inflorescence, and pedicels of the leaves, and circular, and down-facing leaves borne in threes, the central one of which had a long pedicel, to ca. 8cm long .

Drosera marchantii ssp prophylla

Scattered plants of the erect growing tuberous sundew, Drosera marchantii ssp. prophylla, were found growing on the flanks of laterite hills growing in a sand and laterite soil. The plants had finished flowering at the time of the visit, a few of which had already shed their seed. The golden green plants grew to ca. 25 cm tall, had a conspicuously inflated base which was covered by a numerous linear scale-like leaves, had few flowered inflorescences with flowers held on relatively long scapes, had leaves held singularly on the stem, and which often grew in small groups of up to 4 plants probably derived from natural division of the tuber.

Drosera menziesii ssp menziesii

A few plants of the slender climbing tuberous sundew, Drosera menziesii ssp. menziesii, were found near the creek on the property, and were also found in greater abundance in deep sand near Moore River. The plants were in flower at the time of the visit and had red, slender glabrous climbing stems to 30 cm tall. The round leaves were borne in threes up the stem and the pedicels were generally less than 2 cm long. The deep pink petalled flowers were fragrant and had hairy sepals.

Drosera menziesii ssp thysanosepala

A large number of the slender climbing tuberous sundew, Drosera menziesii ssp thysanosepala, were found growing in kwongan vegetation on the upper parts of laterite plateaus in sandy soil with ironstone. The plants were very red in colour, lacked hairs, except for the margins of the sepals, and had leaves in threes alternating up the stem. The pale pink flowers were open at the time of our visit, even under overcast conditions, were sweet smelling and almost circular in outline. I observed a hover fly visiting one flower, perhaps feeding on pollen, and which may act as a pollinator.

Drosera miniata

Abundant plants of the pygmy sundew, Drosera miniata, were found on the upper portions of the laterite plateaus. They grew in soil composed on ironstone with a variable content of sand, in the sandier soils they sometimes grew withD. enneaba. The flat rosettes grew to 1.5 cm diameter, which were often hard to see. The most conspicuous feature of this species were the open flowers, to ca. 8mm diameter, which had iridescent orange petals with dark red, almost black veins radiating out from the black ovary, the later was surmounted by three thread-like styles. The dark red coloured stamens were generally not a conspicuous feature of the open flowers.

Drosera miniata often grew with D. barbigera and the two were often flowering together. It was interesting to note that the flowers of both species were very similar in appearance and size – orange with a dark red centre, yet there were no signs of hybrids between these species.

Drosera pallida

A few plants of the climbing tuberous sundew, Drosera pallida, were found growing near the top of a some laterite hills. This species had finished flowering and was starting to die down at the time of out visit but was identified from the other climbing sundews by the following; glabrous stem, usually 2mm diameter, and sepals; general lime green colour of the plants and rounded, down facing lamina, borne in threes with pedicels often 2 to 4 cm long.

Drosera stolonifera ssp humilis

A few plants of the tuberous sundew, Drosera stolonifera ssp humilis were found at the farm. They grew in sandy soil on the mid slope of a laterite hill and on flat ground near a creek. These many branched plants had stems to ca. 12 cm long and no signs of the remains of inflorescences. The whorled leaves had petioles which were circular in cross section and triangular lamina which the upper corners folded up towards each other. The slender stolon grew across the ground for up to 3cm after it had emerged from above the tuber.

  1. stolonifera ssp porrecta

An abundance of the tuberous sundew, Drosera stolonifera ssp porrecta grew on the property on the flanks and upper portions of the laterite hills. The plants emerged vertically above the tuber and immediately formed two rosettes of short petaled leaves. The plants varied in the amount of branching which occurred above the two basal rosettes. Plants produced between one and ca. five stems, which grew erect, up to 20 cm long. The mature leaves were borne in whorls , had a furrowed petiole and were triangular in outline with the upper corners folded back so that they were almost in contact and which resulted in an almost circular outline to the leaf blade. Many of the branching plants had flowered, and had now shed most of their seed. The inflorescence emerged from the top of the upper basal rosette at the base of the branches. Most plants grew singularly although a few had divided once.

In addition to the carnivorous plants mentioned above flowering plants of  the erect tuberous sundew, Drosera microphylla  had been seen on laterite hills on the property in early winter. The plants had orange petals (M. Hislop, pers. Comm., 1995).

The area near Mt. Lesueuer has a remarkably diverse flora, as indicated by the range of carnivorous plants which were seen there. It is a botanist’s delight to spend time in the area.

Acknowledgements:

I wish to thank the Murdoch Branch of the Wildflower Society of Western Australia for the opportunity to be involved in this vegetation survey, and for the owners of the properties visited  for granting access.

Posted in Field Studies