Re: Aldrovanda (in fact: Drosera)

Jan Schlauer (zxmsl01@student.uni-tuebingen.de)
Thu, 13 Apr 1995 11:12:06 +0100

Tom,

>I also noticed Jan's comment about the Cuban species, D. moaensis and
>the presence of D. intermedia and D. capillaris. Do the southern-most
>examples of D. intermedia have a dormancy where they form a
>hybernaculum?

Nothing is known to me about this but it does not seem very probable. BTW,
Some _Drosera_ species which are perennial in regions with humid summers
seem to become annuals in regions with dry summers in Brazil (F.RIVADAVIA,
pers. comm.). The *southernmost* records of _D.intermedia_ are already from
the "lower" end of the tropical zone (S Brazil- non vidi, F.RIVADAVIA pers.
comm.).

> As for D.
>brevifolia, can it be reliably distinguished from small forms of
>capillaris by the hairy or tentacled scape?

Yes, more or less. The (always glandular) indumentum on the scapes of
_D.brevifolia_ is usually much denser than in the other two species (which
do usually not flower in a stage at which their leaves are so small that
the rosettes could really be confused with those of _D.brevifolia_).

The best distinguishing feature (in the absence of seeds, which are
diagnostic in all 3 species) is in the stipules, however. These are reduced
to two very inconspicuous and sometimes deciduous lateral setae in
_D.brevifolia_, so they are usually not even noticed by the unexperienced
observer, while the stipules of _D.intermedia_ and _D.capillaris_ are well
developed.

Kind regards
Jan