Date: Thu, 18 Feb 1999 19:24:01 From: SCHLAUER@chemie.uni-wuerzburg.de To: cp@opus.hpl.hp.com Message-Id: <aabcdefg494$foo@default> Subject: Re: Hybrids & variety confusion
Dear Peter,
> True with many (most perhaps), but don't forget that almost all
> interspecific Drosera hybrids are sterile (in itself perhaps a good
> reason to regard D.burmanii + sessilifolia as synonymous or at least
> subspecies),
Have you really tested this? So far most _Drosera_ hybrids involving
parents with *equal* ploidy have in fact been *fertile*. The only well
known sterile hybrid (yes, Fernando, I know that there are other
examples but these are not as well-known as this one) is _D. anglica *
rotundifolia_ (cf. my previous, repeated messages to this list!),
involving a (probably hybridogenic, tetraploid) parent with 40
(_D.a._) and a (diploid) parent with 20 chromosomes (_D.r._). Very
much confusion was created by this hybrid, which is, in terms of
fertility, the *exception* rather than the rule. Much of the nonsense
published in the literature concerning hybrid fertility in _Drosera_
can in fact be traced back to this single, rather abnormal (but
widespread) hybrid. The fertility of a _Drosera_ hybrid can
definitely *not* be taken as evidence for the specific identity of
the parents. Likewise, the fertility of a _Drosera_ plant is *not*
definitive proof of its non-hybrid nature.
> and that we know almost nothing about Utricularia hybrids - the
> genus that accounts for ~1/3 of all carnivorous species. Out of
> the ~14 genera of carnivorous plants, I'm only aware of 3 or 4
> that produce fertile interspecific hybrids routinely(-ish) -
> Sarracenia, Heliamphora, Nepenthes and Pinguicula(?)
_Dionaea_, _Aldrovanda_, _Drosophyllum_, _Triphyophyllum_,
_Darlingtonia_, and _Cephalotus_ are monotypic. No chance for
interspecific intrageneric hybrids whatsoever!
> > (...) wether long standing variety's are what we thought they were,
> > for example, is S. Maxima a seperate variety, or just a large form
> > of S. Flava, common
>
>
> It is a distinct form (I'm not sure if it has been properly
> described as a cultivar - I'm sure Jan will let us know! :)
It is a (valid) variety (accepted by yours truly since Don Schnell's
recent revision and clarification) of _S. falva_, i.e a taxon, not an
established cultivar.
Kind regards
Jan
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