Arisaema verrucosum

[guy gusman]

Ray, Roy, All,

I have been quite busy with students from a few days and could not take
part in your discussion about A. verrucosum more promptly.

In Sikkim, for instance, one finds plenty of A. griffithii. If for some of
them, petioles and peduncle are smooth, for others they are warty. One
easily notices the rough surface, like sandpaper, with the hand. But all of
them are growing side by side and one goes in a continuous way from smooth
stalks to verrucose ones. In the same way, the colour also varies from
plain green to purple. The same happens with A. utile. And this is perhaps
at the origin of the confusion.

Of course, if tubers are collected and sold selectively, one could get the
impression, in cultivation, that there are typical "smooth" A. griffithiii
on one hand and "warty" A. griffithii var. verrucosum on the other hand. In
the wild, however, both grow mixed. In fact, the colour and the warty
aspect of petioles and peduncles only have a horticultural interest but no
botanical meaning. These are but normal variations of A. griffithii.
A. utile is a completely different species that also present the same kind
of variation; smooth or warty stalks.
Both species are clearly distinct as it appears from the nice illustrations
in J.D. Hooker's papers both published in 1880 in the Botanical Magazine of
A. utile, t. 6474 and A. griffithii, t. 6491.

One could go further. A. elephas also exists in two versions! But,
fortunately, something like "A. elephas var. verrucosum" has never been
used.

Let us thus discard the name Arisaema verrucosum that is irrelevant.

Arisaema griffithii var. verrucosum (Schott) Hara in Univ. Mus. Univ.
Tokyo. 2: 340 (1971) = A. griffithii

Arisaema verrucosum var. utile (Hooker ex Schott) U.C. Pradhan in Himalayan
Cobra-Lilies, p. 56 (1990) = A. utile (which is often sold in the trade
under the name of A. verrucosum).

Guy (Belgium, zone 8)