Date: Thu, 28 Jan 1999 17:32:52 PST From: "Fernando Rivadavia Lopes" <fe_rivadavia@hotmail.com> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg255$foo@default> Subject: Venezuelan Drosera Taxonomy Doubts
To Jan and others interested in S.American CPs,
Today I went to talk to my friend Rolf Grantsau and take specimens of
the Drosera I collected on my most recent trip to N Brazil and S
Venezuela for him to draw (he wants to make botanical drawings of all
New World Drosera and is helping me tremendously with my taxonomy
studies). My things still haven't arrived from Japan, including all my
Drosera literature and Taylor's book. That is why there were so many
"U.sp." and "(?)" in the list I sent in yesterday. Hopefully these will
be identified soon.
Anyways, Rolf has a lot of literature on Drosera and so we sat down to
analyze some of the things I'd collected. Where do I start?!?! More
doubts than I expected. I thought I knew those plants better, or maybe
people have been paying too much attention to the larger CPs (Helis) and
not enough to the smaller stuff like Drosera -- and let's not even get
into small yellow flowered Utrics!!). Well, a few taxonomic doubts
regarding D.felix, D.kaieteurensis, D.cayennensis, and D.arenicola. hope
somebody can help me.
First of all, the division of D.arenicola into 2 varieties is worthless
if you ask me! I don't have the paper in front of me (at Rolf's), but
the difference in flower scape length cited for D.a.var.arenicola and
D.a.var.occidentalis is minimal -- I think up to 7cm and 8cm
respectively -- and the difference in flower number ridiculous -- 1-10
and 4-10 respectively, I believe. I collected one in Kavanayen - area
cited for D.a.var.arenicola in Flora of the Guyana Highlands -- which
had 14 flowers (damn, I just broke one off by accident while counting!).
Next, D.cayennensis. I remember fotographing what might've been this
species at Bonn during last year's meeting. It was in the small
greenhouse full of Drosera (beautiful D.regia, including the albino
form) which we had to descend to enter. The plants were a pinkish-red
color with short flower scapes near the entrance, remember Jan? Anyways,
the type specimen is supposedly from somewhere around Cayenne in French
Guyana, which is on a coastal plain I believe, where it must be hot and
stuffy just like the D.sessilifolia and D.biflora habitat I saw just
north of Boa Vista in Roraima state, N Brazil.
Yet the ones I believed to be D.cayennensis were growing in the Gran
Sabana in slightly shady habitats at about 1300-1400m. I'm wondering if
this is truly D.cayennensis because of the altitude difference and also
because the plants I saw in Venezuela as well as at Bonn (I think, I'll
have to check the photos I took there - when I find them) had simple
white hairs all the way up the scape as well as on the calyx lobes. The
description of TYPE D.cayennensis I believe said simple hairs only on
the bottom half of the scape and glandular ones on the upper half. I
wonder if there's variation in this character.......
Now the last doubt regards D.felix and D.kaieteurensis. What is the
difference between these two species?!?!?! In the brief time I had, it
seemed like the only difference was that D.felix had a single flower on
a short scape, almost scapeless while D.kaieteurensis has a slghtly
longer scape with several flowers. I found several populations around
the Gran Sabana in areas cited for both species (in Flora of the Guyana
Highlands and the description of D.felix) with plants that had
inflorescences as described for D.felix as well as for D.kaieteurensis,
not only in the same population, but on the same plant!! In fact almost
every mature plant of this species had flower scapes, most of which were
single flowered and short. Yet longer scapes with several flowers were
not uncommon at all.
It seems to me that D.felix is simply based on single-flowered
specimens of D.kaieteurensis, that is, a synonym of D.kaieteurensis,
unless anyone can tell me any other differences between these two taxa
other than inflorescence length and number of flowers.
And now that I believe I have the real D.kaieteurensis in hands, then
the one I found on the Serra do Araca' is NOT D.kaieteurensis! What
species native to northern S.America has spatulate leaves,
inflorescences glabrous, erect, fragile (not as much as D.communis, but
nowhere as thick as in D.kaieteurensis). I'll have to check the seeds
since it could be some form between D.capillaris and its possible
synonym D.tenella, although the plant did NOT look D.capillaris-ish at
all. Nor D.colombiana-ish. Maybe D.esmeraldae???
Best Wishes,
Fernando Rivadavia
Sao Paulo, Brazil
P.S. I'm still on the lookout for flowering specimens of D.linearis
in alcohol for my friend Rolf to draw. If anyone can help me, I can help
you with rare S.American CP seeds....
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