>In my thesis I will describe some remote areals of Drosera
>rotundifolia and D. anglica in the northern Black Forest, Germany.
What's the reason for that topic? For both species, widespread in Eurasia
and North America, the northern Black Forest is not a marginal distribution
area (plant populations of marginal sites show sometimes morphological or
caryological peculiarities). Both do not show - up to now - chromosomal
variations (D. rotundifolia has everywhere 2n=20 and D. anglica 2n=40. As
known since 1955 D. anglica is a tetraploid (amphiploid) stabilized and
fertile hybrid of D. linearis (2n=20) x D. rotundifolia . The diploid
hybrid is morphologically identical with D. anglica but sterile.
The hybrid D. rotundifolia x D. anglica, rather frequent at common sites,
has 2n=30 and is sterile due to disorders in the pollen meiosis.
In the southern Black Forest there are also sites of D. intermedia (2n=20),
likewise widespread in Eurasia and North America, in Europe from
Scandinavia to Portugal and northern Italy. Why don't you at least include
this species?
A friendly advice: I doubt whether your thesis topic would reveal many new
facts. Perhaps it would be wise to reassess it.
Kind regards Juerg
___________________________________________________
Dr. Juerg Steiger, Institut fuer Aus-, Weiter- und Fortbildung IAWF
University of Bern, Inselspital 37a, CH-3010 Bern, Switzerland
Office: +41 (0)31 632 98 87, Fax: +41 (0)31 632 98 71