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From: Ellen Hornig <hornig at OSWEGO.EDU>
Subject: Re: Arisaema flavum ssp. tibeticum
Comments: To: "pbruggeman at tiscali.nl" <pbruggeman at tiscali.nl>
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Dear Guy and Pascal - the most recent spathe to open in the clump appears
to be all-male.  Guy, from the photos I sent you you seemed not to have
any doubts about its identity; Pascal, from your reply you seemed to have
doubts about both its identity and my ability to read Guy's fine book; so
I hope this answers any remaining doubts.

Ellen

*******************************************************************
Ellen Hornig
Seneca Hill Perennials
3712 County Route 57
Oswego, New York 13126 USA
USDA zone 5B (mintemps -10 to -20F)
Phone:(315) 342-5915
Fax: (315) 342-5573
Website: http://www.senecahill.com


On Mon, 6 Jun 2005, pbruggeman at tiscali.nl wrote:

> 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
>