Technical Description. (t.b.d.)

BRIEF DESCRIPTION: The cap of Amanita tainaomby is 20 - 70 mm wide, expanded-convex, with a depressed center, grayish to mouse-gray, with a strongly striate margin. The volval remnants are few, more or less fragmentary, friable, whitish to grayish, and powdery. The flesh is firm, thin, white.

The gills are rather crowded, free, broad, silvery-white to cream, with a marginate edge with brownish black cells.

The stem is 30 - 80 (-150) × 15 mm, cylindric, narrowing upward, white, exannulate, initially cottony-fibrillose, then becomes patterned with brown to mouse-gray fibrils, with brown striations in the upper part. The volva is in the form of an elongated cup, the upper portion is cream colored, the lower part is ochraceous buff or ochraceous orange, rather thick, and friable. A part of the volva remains as a collar which is ochraceous at first, becoming brown on the lower stem. The volval material is occasionally lost rapidly.

The mushroom lacks both odor and taste.

In Gilbert's text, he cites the spores as measuring 9.5 - 10.5 × 8.5 - 10 µm and are globose to subglobose and inamyloid. However, Gilbert points out that similarity to Amanita calopus Beeli which is particularly known for having ellipsoid and elongate spores and his drawing of the spores of A. tainaomby show broadly ellipsoid to ellipsoid spores. The three illustrated spores, which are in appropriate orientation for measurement, measure 11.6 - 14 × 8.5 - 11.2 µm.

This species was originally described from Madagascar (Africa). The type might be taken implicitly as the sole specimen mentioned by Gilbert (collected in Fénérive, 10.xii.1934) however, Gilbert says that he was unable to find spores on what he considered the type. Hence the specimen mentioned (in the caption for the spore drawings) cannot be considered the type, but the issue is moot. The type collection was probably originally split between Madagascar and Paris (in the herbarium of E. J. Gilbert). Any specimens in the Madagascar National Herbarium have been destroyed by fire and Gilbert's herbarium has been lost. This species is reasonably believed to have no type. The only thing said of its habitat by Heim was that it grew near cow manure. 

Heim reported that this species was considered "very toxic" by indigenous peoples of Madagascar. This is very odd because there is no other toxic species confirmed for species in section Vaginatae with a weakly structured volva.  The belief should be further investigated. -- R. E. Tulloss and L. Possiel

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Last changed 23 August 2006.
This page is maintained by R. E. Tulloss.
Copyright 2006 by Rodham E. Tulloss.