Amanita infusca - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita infusca
name status nomen acceptum
author E.-J. Gilbert ex Singer
english name "Dark Slender Caesar"
intro The following description is based on the original description of Amanita infusca (≡A. umbrina Beeli), (Beeli 1935), and (Gilbert 1940 & 1941).
cap The cap of Amanita infusca is 70 - 120 mm wide, subcylindric at first, expanded-convex, fleshy, glabrous, with a long striate margin. The center of the cap is slightly depressed.  The cap is blackish brown with a coal-black center.  The volva is absent.
gills The gills are free, pale, very pale pinkish-white, 10 mm broad, and pointed at the end near the stem.
stem Its stem is 170 - 200 × 8 - 11 mm, streaked with dark colored fibrils, eventually hollow, and tapering upward.  The ring is placed above the middle of the stem and is skirt-like, membranous, and umber-brown.  The volva is membranous, thick, whitish, and saccate.  The stem's flesh is white.
odor/taste The odor and taste of A. infusca are acrid.
spores The spores of A. umbrina measure 9.1- 10.2 × 6.5 - 7.5 µm and are ellipsoid and inamyloid.  The bases of basidia probably bear clamps.
discussion The present species was originally described from the Republic of Congo in association with Gilbertiodendron.

Madame Goossens depicts the fibrils of the stem as significantly browner than the very dark cap and ring.  In her painting, the volval sac is quick thick at the base and the thinner upper part is broadly opened and collapsing like a deflating basketball.  She also shows that the underside of the annulus, at least at first, is pallid with flecks that are concolorous with the colored fibrils on the stem—more reddish brown than fuliginous or dark brown.

Amanita infusca sensu Pegler and Shah-Sm. (1997) is a somewhat similar mushroom from Zambia, but, given the state of knowledge of A. infusca, the Zambian material may be an undescribed species.  The cap, rather than being coal black in the center, is sometimes yellowish-brown; the stem is often shorter than the cap's diameter; the annulus is described as pale to reddish-brown; the saccate volva has a reddish-brown margin; the odor is very faint; and the spores are larger, so far as can be told, although similarly shaped.—R. E. Tulloss
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