The following description is based on the desription of Beeli (1935) and Gilbert (1940 & 1941).
The cap of Amanita robusta is 120 mm wide, globose then expanded-convex, glabrous, viscid then dry, brick red, center becoming dark violaceous, with a lightly striate margin. The flesh is firm and white. Usually no volval remnants are present.
The gills are free, yellowish, and pointed at both ends. The short gills have not been described.
Its stem is 130 × 10 - 25 mm, fibrillose, cylindric, and stuffed. The ring is fibrous and ephemeral, leaving some cob-web like debris on the edges of the gills. The volva is ample, membranous, saccate, thick, brownish ochraceous and warted on the outer surface, violaceous? [appears the same color as the cap surface in Mme. Goossens' watercolor—ed.] on the inner surface. The flesh is firm and white.
The taste is sweet. No odor was reported.
According to the spore drawings of Gilbert (1940), the spores measure 9.1 - 10.1 (-11.2) × 6.6 - 7.7 (-9.2) μm. The spores are ellipsoid and inamyloid. No one has examined the basidia for the presence of clamps.
The present species was originally described from the Republic of Congo from a forest of Gilbertiodendron.
Indeed it is the case that because of its robust stature, pigments of the cap, short marginal striations of the cap, robust volval sac, and the yellow gills, the similarity is rather strong. However, the presence of a bulb at the base of the stem and cortina-like partial veil exclude the present species from the Caesareae.
Well-dried modern collections with good notes on the fresh fruiting body and a photograph are very much needed.
Rammeloo and Walleyn (1993) reported a method of cooking of a mushroom close to A. robusta. First it is blanched in boiling water which turns yellow. It is blanched when the the caps are closed. Then the caps may be pealed and are cut into pieces and sautéed in oil with sliced onions, salt, and chilis. The taste of the boiled fungus is described as strongly fishy and "green." When sautéed, the flavor is described as "strong"; and of the flesh it is said that it "leaves a bitter taste in the mouth."—R. E. Tulloss
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The following material is derived from the protolog of the present taxon, (Beeli 1935), and (Gilbert 1940 & 1941).
from protolog: 120 mm wide, brick-red, with disc becoming dark violaceous, flattened ovoid, smooth, viscid then dry; context fleshy, firm, white; margin lightly striate (ca. 0.25R per Gilbert (1941: tab. 13)); universal veil absent.
from protolog: free, density not described, yellowish tinted white, 15 mm broad; lamellulae not described.
from protolog: 130 × 10 - 25 mm, white, cylindric, fibrous, smooth; bulb present at least in button (per figure); context hollow, firm, white; partial veil ephemeral, fibrilloe, leaving cortiniform elements on lamella edges; universal veil saccate, membranous, very thick, fleshy, with brownish verrucose exterior, encompassing ca. one-third of mature stipe per Gilbert (1941: tab. 13).
Beeli (1935): universal veil ochraceous-brownish on the exterior surface warts, "violaceous" [concolorous with pileus surface in Mme. Goossens' watercolor—ed.] on inner surface.
Gilbert (1940 & 1941): [2/1/1] 9.1 - 10.1 (-11.2) × 6.6 - 7.7 (-9.2) μm, (L = 9.6 μm; W = 7.2 μm; Q = 1.32 - 1.38; Q = 1.35), hyaline, smooth, inamyloid, ellipsoid; apiculus sublateral and subcylindric (per figure); contents not described; white in deposit. [Note: Spore measurements are taken from the two drawings of (Gilbert 1940: tab. IX (fig. 3)) that are in approximately lateral view.—ed.]
from protolog: In groups. On soil in Gilbertiodendron (=Macrolobium) dewevrii forest.
There is only one described species of Amanita that is similar to A. robusta—A. pudica. The following figure compares the sporographs of the two taxa. Unfortunately, the data for the present species is extremely limited at present.
—R. E. Tulloss
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