Re: naphtochemistry

Jan Schlauer (
Wed, 14 Jun 1995 11:58:59 +0100


>Maybe we should change our views on the section Drosera...Maybe this
>section sould be divided up into more sections...

Well written! This is what I intend to do, indeed.

>It is rather strange that
>plum. occurs in D.intermedia and not in D.rotundifolia and D.anglica... I
>think it is very likely that those species can therefore NOT be (very)
>closely related.

Exactly so. They should be separated (not only because of
naphtho-differences). I also think that _D.uniflora_ is much closer to
sect. Drosera s.l. and _D.brevifolia_ is more remote from sect. Drosera
s.str. than has been thought before (e.g. DIELS).

>Laenger et al. also mention that the sect. Rossolis (which
>is the old name for sect.Drosera I think


>...) is the only section were
>non-glandular occur. But there are 5 exceptions D.filformis, D.tracyi,
>D.rotundifolia, D.intermedia, D.anlica.....

You see, the conclusions drawn from tentacle morphology (or phytochemistry)
alone are rather puzzling. _D.filiformis_, _D.filiformis var.tracyi_
(sic!), and _D.i._ belong to groups to be separated from _D.anglica_ and
_D.r._. Similar problems arise with some S AF species. I prefer a
combination of pollen, style/stigma, seed, and stipule morphology, and
chromosome base numbers as these characters seem to be more "conservative"
in the genus.

But still I do not think I have found an entirely satisfactory subdivision
of the former sect. Drosera s.l., as I have tried to group them into
"diagnostic" assemblies which are not necessarily monophyletic or
holophyletic for my key (publ. in preparation). Anyway, I believe at least
my subgenera are mono- and holophyletic (however, further research may

Kind regards