Date: Mon, 17 May 1999 18:10:43 +0000 From: SCHLAUER@chemie.uni-wuerzburg.de To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1705$foo@default> Subject: Re: Drosera rotundifolia var gracilis
Dear Nigel,
> Looking through E Hulten's Flora of Alaska and Neighboring
> Territories, I found a reference to the small-leaved Drosera
> rotundifolia var gracilis. Is this variety still recognised, and if
> so, how exactly can it be distinguished from var rotundifolia?
It has apparently never received any great appreciation (outside
Hulten's own work, of course), and I do not know of any other
recent author who recognized this variety. Small and large plants
(with varying degrees of bract formation and scape furcation)
occur together with all intermediates, and there seems to be
close to nothing that warrants any taxonomically meaningful
distinction.
There are few species in _Drosera_ that are so remarkably
constant in their *distinguishing* features (stipules present,
lamina at least as wide as long, leaf distinctly petiolate, scape
glabrous or at the most minutely glandular, seeds fusiform)
throughout their range (_D. rotundifolia_ has the largest range
in the whole genus in terms of area covered, and only
_D. intermedia_ spans more degrees of latitude), so there is
really little reason for infraspecific classification in
_D. rotundifolia_ based on doubtful criteria.
On the other hand, _var. bracteata_ from New Guinea lives several
thousand km away from its nearest relatives, and it is the only
representative of this species (if it really belongs to this species; but
it seems to be unseparable) occurring in the tropics and S of the
equator. Some distinction is probably appropriate here but further
study is clearly indicated.
Kind regards
Jan
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