>?, if the chromosome counts are this different, can plants the plants
>cross breed? If not, then it seem to me that even though they appear
>to the eye to belong to the same species, even if at subsp. statis,
>clearly they do not. Has this been put to the test?
In plants and especially in _Pinguicula_ the situation is not as simple as
you might think. Even different species with as widely different chromosome
numbers as 2n=22 and 2n=32 can produce fertile (!!) offspring. 32 and 48
are only members of a series with x=8. On the other hand it is nothing new
that *within* a single species different ploidy levels are found (the
_P.crystallina_ complex includes plants with 16, 24, 32, and 48
chromosomes). Another example (this time even from sect.Pinguicula itself)
may be _P.balcanica_ with 24 and 32 chromosomes (2n=24 needs confirmation).
The _P.longifolia_ complex is interesting because at least one taxon is
widely recognized as a distinct species (_P.vallisneriifolia_). Between the
populations of "pure" _P.longifolia_ (e.g. subspp.reichenbachiana,
caussensis, and only with reservations subsp.longifolia) and _P.vall._
there is a considerable geographic gap. And just this gap is filled by the
morphologically intermediate and chromosomally different "transitory"
subsp.dertosensis and _P.mundi_. It is a pity that our Spanish colleagues
did not study their plants on a more global scale. Otherwise they would
have paid much more attention to _P.longifolia_ with all presently known
subspecies (especially those from *outside* Spain), and they would e.g.
have realized that a comparison with _P.grandiflora_ is essentially
nonsense.
Kind regards
Jan