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[pbruggeman at tiscali.nl]

hardy  Aroids)" <ARISAEMA-L at NIC.SURFNET.NL>
From: "pbruggeman at tiscali.nl" <pbruggeman at TISCALI.NL>
Subject: Re: Arisaema flavum ssp. tibeticum
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Dear Ellen,

What Guy already mentions in his book and his reply is
that the main difference between both ssp. according to Murata is that
ssp. tibeticum is able to not only produce bisexual flowers but also
male-only plants. Problem is that due to insufficient fieldwork at the
moment it is unclear if this difference is stable. Given the fact that
both forms (or ssp.if you like) seem to occur in Tibet suggests that
there can be an overlap in distribution range and it is even possible
one form slowly changes into the other without geographic separation.
The features you describe for ssp. tibeticum can, to some extent, also
be applied to ssp. flavum, the Arabian form of flavum. I have seen
several herbaria specimens of plants collected in Yemen that have the
inflorescence held well above the, often not fully unfurled, leaves and
although this ssp. should also have predominantly yellow spathes, many
specimens showed a distinct purple blotch with large, horizontally held
spathes similar to what ssp. tibeticum ought to look like. There is
difference in chromosome count between ssp. tibeticum and ssp.
abbreviatum & ssp. flavum but it is very hard to prove a multiplication
of chromosomes is the cause of this a different sexual behavior. With a
species with such a big distribution range there is a big chance
deviations from the norm will occur and I highly doubt the existence or
absence of a blotch is a good feature to distinguish both ssp. on.
Also, 2 distinct ssp. usually do not have overlapping distribution
ranges but if there is a difference that justifies a separate status
then it should be the existence of male only plants combined with a
higher chromosome number. WIthout the existence of male-only plants
your plant could by definition not be ssp. tibeticum sensu Murata.

Pascal