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[ Keys & Checklist/Picturebooks ] "Black Slender Caesar" = Amanita umbrina Beeli non Amanita umbrina Pers. :: Technical description (t.b.d.) BRIEF DESCRIPTION: The following description is based on Beeli (1935) and Gilbert (1941). 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 dark umbrinous brown with a coal-black center. The volva is absent. The gills are free, pale, very pale pinkish-white, 10 mm broad, and pointed at the end near the stem. Its stem is 170 - 200 × 8 - 11 mm, fibrillose streaked with dark color, becoming hollow, and cylindric. The ring is superior, skirt-like, membranous, umber-brown. The volva is membranous, thick, whitish, and saccate. The flesh is white. The taste and odor are acrid. The spores of A. infusca measure 9 - 10 × 6 µm and are ellipsoid to elongate and inamyloid. Measurements of Gilbert's drawings of ellipsoid spores (1941) are as follows: 9.1 - 10 × 6.4 - 7.3 µm. Basidia probably have clamps at their bases. 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 not be contaxic with the Congolese type. The cap color 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, but similarly shaped. From the microscopic details, the Pegler and Shah-Smith material belongs in stirps Hemibapha. -- R. E. Tulloss
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