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Amanita cystidiosa O. K. Mill. & Lodge :: Technical description (t.b.d.) BRIEF DESCRIPTION: This species must be excluded from Amanita. This description is based on the original description (2000) with additions based on a partial revision of the holotype. The cap of Amanita cystidiosa is 20 - 47 mm wide, convex, becoming nearly plane in age, somewhat slippery when wet, pale straw yellow, with a finely sulcate-striate margin. The flesh is white, unchanging, and firm. The cap is covered with a very fine mealy, white remains of volva. Gills are free, ventricose, subdistant, yellow, and paler when young. Short gills are present in at least two tiers. The stem is 19 - 52 × 4 - 7 mm, white, cylindric, with an abrupt round basal bulb. The bulb is covered with yellowish, appressed remains of volva, and fine, white hair-like hyphae extend from the base. The ring varies in its position on the stem, and usually flares upward. The flesh is white, unchanging, and firm. The center of the stem is stuffed. According to the original description, the spores measure 7 - 9 (-10.5) × (4.8-) 5.5 - 6 µm and are broadly ellipsoid to ellipsoid and inamyloid, with walls varying from thin to somewhat thickened. RET's examination of the holotype produced the following spore data: (7.3-) 7.5 - 10.5 (-13.5) × (5.4-) 5.5 - 6.6 (-7.5) µm, dextrinoid, ellipsoid to elongate, occasionally broadly ellipsoid, rarely cylindric, with walls consistently 0.5 µm thick. Clamps are not present at bases of basidia. The mushroom occurs solitary to scattered in the sand of dunes and foredunes close to Coccoloba uvifera and the cocoplum (Chrysobalanus icaco). [Deleted by RET: It is probably a symbiont of the former. In recent years, a growing number of Amanita species have been collected in association with Coccoloba: A. dunicola Guzmán, Amanita arenicola O. K. Mill & D. J. Lodge, and Amanita microspora O. K. Mill. Additional, probably undescribed taxa seemingly associated with Coccoloba are currently being revised from countries in or around the Caribbean.]Note (1 October 2009, RET): Amanita cystidiosa was originally described from Puerto Rico. The authors maintain that the marginal cells of the gill are derived from the tissue of the gill and, hence, should be treated as cystidia. If this had been true, it would have been a unique situation in the genus Amanita. Note (27 February 2007, RET): Revision of the holotype of this species reveals that it lacks both bilateral gill trama and acrophysalidic stipe tissue -- the two character states defining the genus Amanita. Moreover, it was observed that the spores are thick-walled and dextrinoid and lack the usual adaxial flattening seen in Amanita spores. The protolog reports dextrinoid hyphae in the pileus and cheilocystidia, which are illustrated in the original description. These two character states are also unknown in Amanita. It is necessary to examine both the lamella trama and stipe context in the process of revising any material suspected of falling in the genus Amanita. -- R. E. Tulloss Last changed 1 October 2009. |