_Heliamphora_, again!

Jan Schlauer (zxmsl01@studserv.zdv.uni-tuebingen.de)
Sun, 9 Jan 1994 19:49:47 +0100

Andreas, you wrote re: the MAGUIRE specimen:

>I'd be not completely sure about this...

I'm never *completely* sure about anything. Remember I'm not sufficiently
dead! 8-)

>...as a plant most likely to be a natural hybrid between H. ionasii and
>another doubtful sp. occurs on the common Base of Ilu and Tramen which
>looks much like a small H. ionasii with short hair, that means much
>like H. nutans (I inexcusably call this one H. spec "2" at the moment

The MAGUIRE collection is not the only record of _H.nutans_ from the Ilu
range. Moreover, there are several specimens collected between Mt. Roraima
and Mt. Ilu-tepui. Do you assume all of them to be either hybrids or your
"spec. 2"? *ALL* other authors call it _H.nutans_. Why do you think it is
not this species (maybe a var.)?

>I think best would be a study based on RFLP or other methods which
>stronger estimate the genotype rather than the phenotypic expression
>to claryfy such questions.

RFLP is a good method to examine the hybrid nature of an individual, but
you mustn't underestimate the phenotype as it is responsible for an
important component of evolution (viz. selection). In such variable
taxa, it seems desirable to see as many individuals (from different
populations) as ever possible and study them (if you want so, also
genetically). But the results make very little sense (if any) if you
pick out just a few individuals and then examine every single molecule
of them: you will never grasp the range of variability. You see, it's
rather a problem of material than of method.


>However both groups of mountains are about 170km from each other
>with no mountain or tepui in between to "jump" on.
>As the seeds of Heliamphora are not equipped to being distributed by
>the wind nor by animals (no "fruit" to be eaten by animals, no hair to
>cling into hair or birds feathers) but for swimming...

Swimming seeds may be attached to (wet) hair and feathers, BTW.

>...which should
>explain populations of H. nutans and H. heterodoxa down from the
>tepuis in the Grand Sabana I can hardly imagine how a Heliamphora
>seed could span such a distance.

I agree, this is perfectly true. Nowadays! The tepuis are built of
sandstone massifs (prone to rapid erosion), the gaps between them being in
fact river valleys of (geologically!) rather modern times. It seems,
evolution in _Heliamphora_ is heavily dependent on spatial isolation due to
interfertility. If populations have not been isolated from each other in
the past (and there are reasons to assume so), no specific or varietal
limits could have evolved until "recently". Thus, all the different spp.,
vars., and ff. are comparatively young, whereas the genus must be rather
old, with some of its relatives as far away as (and restricted to)
California and Oregon. I do not doubt there are differences between the
Duida and Neblina populations, I just don't see a reason why these couldn't
be described by varietal distinction.

>All the other species have very small ranges (with the exception of H.
>heterodoxa var. exappendiculata,...

_H.nutans_ (Roraima-Ilu) and _H.minor_ (Auyan-Chimanta) do have rather
impressing ranges, too.

>... which after having seen
>photographs of this plant seems to be something very special to me...
>. I almost do not dare to write, however I do not see much similarities
>to the type-heterodoxa:-)).

The only thing I can say is MAGUIRE *and* STEYERMARK *did* see them (and,
as far as I can judge, I can see them, too).

It seems you want to shift ranks in the whole genus, with vars. becoming
spp. Should then the spp. become sections, subgenera, or even distinct
genera? A funny parallel can be seen in the work by STUDNICKA & al.:
Heliamphora -> Heliamphoraceae. Just explain to me, what's improved? The
result is an increase in the number of names, not of knowledge. And then,
there will come the "grand unificator" who lumps all _Heliamphora_ species
into a single one. He'll be as correct as you are; it just depends on
species definition. Since the times of Linnaeus, the definition and
circumscription of species and other ranks has been discussed excessively,
but neither of the phenomena which may be observed in nature is as static
as any of these definitions. So IMHO, as long as the ranks do represent
comparable taxonomic units within their superordinate taxon, they shouldn't
be changed. i.e. a var. in _Heliamphora_ need not (and cannot!) be
comparable to a var. in _Drosera_. One task of nomenclature is description.
The other (as important as the first) is *stability*.

Sorry for the long reply!