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From: Susanne Renner <Renner at UMSL.EDU>
Subject: Ariasaema flavum variability
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Robin Bell asked about A. flavum: " So, my questions are: I
have read that it is a very variable species with forms that have
large flowers, are there some that have attractive flowers that are
in cultivation? The other question is has anyone tried crossing it as
the color on a different plant form could be very appealing & perhaps
justify keeping it around for this purpose alone. What other
experiences are out there with flavum?"

While I do not know A. flavum in the field or greenhouse and do not know
about experimental crosses, literature on this species confirms that it i=s
unusually variable in chromosome number and inflorescence size.
Publications before 1990 also describe A. flavum as a non-sex-changer.
However, a sex-changing subspecies of A. flavum has been discovered
(Murata, 1990).  It is diploid and has relatively large spadices.  The
other two subspecies of A. flavum are tetraploid, have minute spadices (c.
1-1.5 cm long), and are the only arisaemas capable of selfing (Vogel &
Martens, 2000).

Because of its unusual male flowers with a single stamen and the supposed
absence of sex change, A. flavum has been considered both as "pheneticall=y
most primitive" (Grayum 1990) or as "derived" (Li, 1981, Vogel & Martens,
2000).  The species ranges from Ethiopia across the Yemen and Saudi Arabi=a
to Tibet and into Szechuan.  A molecular phylogeny of 47 species of
Arisaema suggests that A. flavum is part of a derived clade of arisaemas
(molecular tree posted at http://www.umsl.edu/~biosrenn/ -- click on
Arisamea), rather than being an early off-shoot.

Susanne Renner

Grayum, M. H. 1990. Evolution and phylogeny of the Araceae.  Ann. Missour=i
Bot. Gard. 77: 628-697.

Li, H. 1981. Himalayas-Hengduan Mountains - the center of distribution an=d
differentiation of the genus Arisaema. Pp. 1321-1327 in: Geological and
ecological studies of Qinghai-Xizang Plateau, vol. 2. Science Press,
Beijing.

Murata, J. 1990. Three subspecies of Arisaema flavum (Forssk.) Schott
(Araceae). J. Jap. Bot. 65: 65-73.

Vogel. S., and J. Martens. 2000. A survey of the function of the lethal
kettle traps of Arisaema (Araceae), with records of pollinating fungus
gnats from Nepal. Bot. J. Linn. Soc. 133: 61-100.