Re: Hybridization trends

Jan Schlauer (
Sat, 18 Jun 1994 12:09:59 +0100


> Anyone know what the chromosome count is for Sarracenia, Darlingtonia,
> and Heliamphora? Is it different for the various species?

_Sarracenia_ (all spp.) 2n=26
_Darlingtonia_ 2n=30
_Heliamphora_ (_nutans_/_minor_) 2n=42

> I think I remember seeing a message from someone here on the net that said
> that the various Drosera have different chromosome counts.

That is true, essentially. But e.g. in sect. _Drosera_, most species do
have 2n=20, a few being part of a polyploid series with 30, 40, 60, 80
chromosomes (sometimes even different individuals of the same species).
Thus, chromosome numbers are generally not very valuable for taxonomy
within this section (which is the most complicated of the genus).

An exception may be the case with _D.anglica_ (4x=2n=40) which is closely
related to _D.rotundifolia_ (2x=2n=20). This might indicate that
_D.anglica_ evolved from a stabilized (fertile) hybrid involving
_D.rotundifolia_ and another species with 2n=20. Disturbed meiosis without
chromosomal seggregation may have led to doubling of the chromosome number.
The hybrid between _D.anglica_ and _D.rotundifolia_ has 3x=2n=30 and is

Kind regards