For further elucidation, here's what Fernando posted to the CP liserve regarding this species:
Date: Fri, 29 Jan 1999 11:37:21 PST
From: "Fernando Rivadavia Lopes" <fe_rivadavia@hotmail.com>
To:
cp@opus.hpl.hp.com
Subject: Re: Drosera sessilifolia
Message-ID: <19990129193728.25958.qmail@hotmail.com>
To Matt and Jan,
>Without a flower, I guess no human being will be able to tell these
>two species apart (if they are not labeled, of course).
Well Jan, there is at least one human capable of telling them
apart without flowers: ME! And I believe my good friend Ivan Snyder in
L.A. (the one who hybridized both species) may be even better than
myself, since he has to tell them apart in cultivation, when
D.sessilifolia is usually rather small and puny for some reason.
It's true they are VERY similar species, but they're not too
hard to differentiate in cultivation when you have the common form of
D.burmannii. I've seen some odd forms of D.burmannii from N Australia
which had quite weird leaf shapes and very red leaves. These may be a
bit more confusing. Basically, the leaves of D.burmannii are more
triangular and those of D.sessilifolia more rounded. The leaves (or
tentacles) of the latter are also usually more reddish or pinkish. If
they flower, you'll see erect scapes with pink flowers on D.sessilifolia
and ascending scapes with white flowers in D.burmannii (although I've
seen forms of this species with erect scapes and I think I've at least
heard of pink flowered specimens too).
Having just seen D.sessilifolia in the wild again, I've
gained a few new insights into this curious species, or at least
hypothesis. Me and a few others have noticed that in cultivation
D.sessilifolia is always a miniature of what the parent plants looked
like in the wild, never growing very large. When I found them N of Boa
Vista last week, I noticed they were growing only in a small area near a
road, where there were some houses, and where horses and cows
occasionally passed by. Yet while exploring further away along the
river, Gert and I could find no signs of D.sessilifolia, although there
were apparently many good habitats.
So what is going through my mind at the moment is that
D.sessilifolia may need some kind of fertilizer to grow, both in the
wild (from animal droppings) and in cultivation. It would be interesting
to test this in cultivation, adding different types of fertilizer to see
how big the plants get. If it is true tha D.sessilifolia likes areas
fertilized by animal droppings, then we can speculate that
D.sessilifolia was VERY common until a few thousand years ago, back
before the natives dined on the last mammoths, giant ground sloths, and
other extinct S.American megafauna species.
Best Wishes,
Fernando Rivadavia
Sao Paulo, Brazil
