Date: Tue, 6 Oct 1998 00:05:35 EDT From: Kg6ui@aol.com To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3209$foo@default> Subject: Queensland Drosera - Robert Gibson
Hello all!
At last June's BACPS club meeting, we were very fortunate to receive a most
absorbing presentation and slide show from Robert Gibson of Australia,
concerning CP's he has personally encountered in his many travels around the
world. As the Dark Tropicals from the Cape York peninsula of Queensland
particularly interest me, I asked him if he could direct me to other
literary/research resources concerning these, as my library is very limited.
He also mentioned that on his way home, he would be doing some extra
travelling, and might even make it up the Peninsula, but wasn't exactly sure
if he could swing it.
Anyway, I recently received a letter from Robert Gibson, and I believe the
information in it will probably thrill those of you who count these drosera as
their favorites. So, Robert's comments starting now:
Earlier this month I had a 3 week trip up the eastern Australia coast to
Cairns. I had hoped to see at least one of the three rainforest Drosera from
the area but did not get to any sites. However, from study in the Queensland
state library in Brisbane and a walk through the pass between Mts Bartle Frere
and Bellenden Ker I can pass on the following which may be of use to you.
Drosera schizandra, which is endemic to the Bellenden Ker range (south of
Cairns and which contains the highest peak in the state), appears to be
restricted to shaded creek banks at altitudes of at least 440 metres (ca. 1300
feet). During the walk through the rainforest on the northern foot of the
mountain I saw that the ground was commonly covered with Selaginella species.
As for the fauna leeches may be added for realism, but this is probably a bad
idea:-). From photos in Kondo and Kondo (1983) it grows in local clearings,
on sometimes steep slopes sometimes in the company of tree seedlings, and the
rosettes reach 30cm across! Apparently there is a location 3km away from a
road which is accessible on foot. Without this location I was going to check
it out on a trek to the peak - regrettably this did not happen but this trek
is quite arduous, leaving at 5am and returning by 7pm.
Drosera prolifera occurs at "a couple of localities at very high altitude in
north Queensland. The area receives a tremendous amount of rain and these
plants form extensive mats near the summit of the peaks on which they are
found. The area is one where a lot of seepage occurs and it is reported that
these areas often occur aound extensive areas of open rock which form the
slopes of the mountain side" (Williams, 1984, page 114). They are found above
900m (2900 feet) around Thornton Peak, near Cape Tribulation, north of Cairns.
The accompanying photo [in the book reference] shows a mass of leaves, but no
flowers, and a few fronds of a blechnum-type fern. It appears that the plants
growing were in an open area, given the small size of the leaves and red
retentive glands, but it is likely that they rarely see the sun due to
frequent local cloud development.
Drosera adelae "appears to be confined to a small area of north Queensland. I
have observed the species on Hinchinbrook Island and on the mainland opposite
the mainland. It forms colonies of rather limited extent but these are
scattered in many different areas. The plant appears to be influenced more by
situation rather than by soil. There seems to be a constant soil moisture
factor and perhaps at times the plants would experience a great deal of actual
wetness. I have seen the plants growing on almost perpendicular clay banks
that contain a lot of water-worn stone and in sheltered pockets where there
were granite rock ledges. The soils on the ledges have developed from
vegetable debris or have been trapped by the plants. They become somewhat
peaty in texture. The flowers are small, brownish in colour and very
inconspicuous" (Williams, 1984, page 114). The accompanying photo [book
reference] shows a few scattered plants, with elongate leaves on apparently
thin moss-covered soil over granite in an apparently open, possibly sunny
location on what may be a creek edge. From this account, and personal
communications with Paul Simmons whose sister has seen this species on
Hinchinbrook Island that this is the location of the brownish petal colour
form which has been in cultivation for decades. Perhaps the red flowered form
is from near Cardwell?
The three species grow on rugged granite mountains which retain a cover of
rainforest. From my observations of the country around the Bellenden Ker
range and Hinchinbrook Island it is likely that the plants grow in small,
isolated colonies, and it would be so easy to miss seeing them when
walking/scrambling through the area. This may explain why there are a few
different flower forms of D. schizandra and D. adelae. As for D. prolifera it
is possible to hike to the top of Thornton Peak, but it is an arduous trek and
it claimed the life of a tourist recently. In order to see all species in the
wild would require a full day for each species plus time to recover and travel
between the locations. I would not be surprised if more forms, or even an
undescribed species or two are found by an adventurous walker in the future.
In brief the species appear to grow with few other large plants and are likely
to be found with ferns, mosses, selaginella and a few shrub seedlings. The
main reference is Williams, K.A.W. 1984. NATIVE PLANTS OF NORTH
QUEENSLAND:VOL.2 Printcraft, Brisbane, pp. 304. These three Drosera do not
appear to grow in the company of other carnivorous plant species.
As for other carnivorous plant species which grow in dark rainforest
environments the only species have seen which does anything similar is U.
monanthos in western Tasmania. This species is common in swamps and creek
beds but I have seen it in puddles on a few dirt roads through temperate
rainforest. I recall that some nepenthes have shade-seeking tendrils which
will not develop traps unless in a dark environment. From memory these
include N. rafflesiana and N. arnoldii, but the rest of the plant grows in
full sun. I suspect you may have more success in finding shade-tolerant
Utricularia, particularly from South America. I have heard that U. calycifida
detests strong light levels.
Well, that's it! Pretty great information, would'nt you agree? I also
understand better now why Nigel Hurneyman's soil mixture of 50% sieved
sphagnum peat and 50% lime-free quartz grit (decomposed granite, to a large
degree) is so effective for him in raising these plants.
Please forgive me for such a large message, and I know there is a way to send
an attachment to a file, but I am not the computer guru here, and my husband
(who is) won't be back until very late tonight. Not sure I'll get a better
chance given the new job I now have, and all the other things a wife has to
get done around here.
Best Regards to All!
Debra Blanke
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