Date: Mon, 22 Dec 1997 21:22:44 +0900 From: ss66428 <ss66428@hongo.ecc.u-tokyo.ac.jp> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg4782$foo@default> Subject: South American/African Drosera
To all,
Here's a part of a personal message (with a few modifications) I sent
to Matt in reply to his query on South American and African CPs, more
specifically Drosera. I decided to send this to the listserv as it might be
of interest to more people and also in hopes that someone could add to what
I've said.
Both G.violacea and D.graminifolia grow on highlands of Minas Gerais
in Brazil marked by a wet season in the summer and a dry season in the winter.
Temperatures vary more from day to night than from season to season, hanging
more or less around 25-35C during the day and 5-15C at night. Both species
like high humidity and cold running water over the soil (keeping the roots
cool, as with Darlingtonia), but should never be kept in stagnant water in
cultivation, with only humid soil if you don't have a flow-table type
arrangement in a greenhouse.
I've found both species in live Sphagnum, sand, and peat. The dormancy
mentioned by someone on the listserv for his D.graminifolia is not normal and
is due to unusual stresses of cultivation (maybe the heat, as he suggested).
I've never seen the real D.kaieteurensis nor D.cayennensis in
cultivation, but don't doubt that some people have it, considering all the
expeditions there have been to the Roraima region. D.arenicola var.arenicola,
D.esmeraldae, and D.tenella are possibly also in cultivation, although the
identification of the latter two is rather difficult (looking like spatulatas)
and the taxonomy of the latter being somewhat dubious. The only Drosera from
the Roraima region which have succesfuly been introduced to cultivation are
D.intermedia "Mt.Roraima" and D.roraimae (to a lesser extent). I *WISH*
D.meristocaulis was in cultivation, AND HOW! This is one bizarre species which
I would die to have material of for my DNA work!!!!
Of the several known tropical African species (I'm sure there are
many more waiting to be discovered), only D.madagascariensis, D.dielsiana,
D.collinsiae, and D.nidiformis are for surely in cultivation. The latter has
been under much taxonomical debate and its status is much disputed. D.madagas-
cariensis is extremely variable and a long-stemmed form with small reddish
leaves is in cultivation, very different from the short-stemmed form with
large green leaves I collected in South Africa.
D.affinis is supposedly very similar to D.madagascariensis, if not the
same species, and has a long stem. So if your plants are flat rosettes, then
they probably are D.spatulata (as is the case with your D.sp."Brazil", which
I've also grown before and always turned out to be D.spatulata).
D.indica is also cultivated, although none are African forms. Most are
from Australia and because it is an annual species, it is extremely difficult
to maintain.
I've grown the true D.natalensis years ago, but doubt that most of the
ones so labelled in collections are truly this species. I have never seen true
D.burkeana in cultivation (except for the ones I collected myself in South
Africa and which are hopefully still alive in a few collections down there),
although numerous people around the world grow plants thus labelled. All other
tropical African Drosera, or more precisely non-Cape Region Drosera, are still
to be introduced successfully into cultivation as far as I know.
Best Wishes,
Fernando Rivadavia
Tokyo, Japan
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