I stated that 'due to the chromosome number difference of D. roseana
(2n=6) and D. paleacea (2n=10) the first named is not to be considered as
a subspecies of the second named taxon, particularly as they even have no
common basic number'.
You both consider it as possible to have different karyotypes even within
one single species. Yes of course, this is known from different plant
species. But the question arises whether different karyotype members of
the same 'species' can produce fertile seeds if hybridized. If yes ok, if
not (which is more likely in case of different chromosomal basic numbers)
it is doubtful whether both parent groups might be considered to be members
of the same 'species' or 'species and subspecies' sensu strictu. They would
be rather members of a species/subspecies system in the broader sense
(gamodeme aggregate). Drosera has many aggregate species and I guess
experimental evidence of hybrid fertility of D. paleacea and D. subsp.
roseana or other subspecies isn't yet available. Nucleotide sequence
analysis will certainly reveal interesting results.
Juerg
___________________________________________________
Juerg Steiger, Institut fuer Aus-, Weiter- und Fortbildung IAWF
University of Bern, Inselspital 37a, CH-3010 Bern, Switzerland
Office: +41 31 632 9887 Fax: +41 31 632 9871