Entoloma sulcatum (T. J. Baroni et Lodge) Noordel. et Co-David, in Co-David
Index Fungorum number: IF 513791
Pileus 17 mm broad, convex with a depressed centre, not hygrophanous, slightly radially sulcate-striate, sericeous fibrillose overall, yellowish white (4A2) to orange white (5A2). Lamellae adnate-emarginate or adnate with a decurrent tooth, ventricose, first whitish then orange white (5A2) with irregular whitish edge. Stipe 40 _ 2—3 mm, cylindrical, slightly broadened towards the base, fistulose, smooth, glabrous, polished, white. Context thin, white. Odour indistinct, taste not reported. Spores 9.5—11.8 _ 6.7—8.3 μm, Q = 1.3—1.6, heterodiametrical with 5—7 angles in side view. Basidia 22.0—31.2 _ 9.3—10.8 μm, 2—4-spored, clavate, clampless. Lamellae edge sterile. Cheilocystidia clavate to broadly clavate, 31.4—53.3 __ 11.8—20.2 μm, colourless. Pileipellis a cutis of repent and slightly ascending colourless, not encrusting hyphae, 5—10 μm wide, with transition to a trichoderm in the centre, made up of cylindrical hyphae with inflated terminal elements, 7—15 μm wide, without clamp connections. Oleiferous hyphae and brilliant granules absent.
Distribution: Puerto Rico (typus); Vietnam.
Collection: Vietnam, Lam Dong Prov., Lac Duong Dist., Bidoup-Nui Ba National Park, Giang Ly Ranger Station, 12°11´00´´ N, 108°40´44´´ E, 1450 m alt., on soil in secondary grassland with signs of recent burning, 26 June 2010, leg. E. Popov, LE 262913.
Comments: Despite the fact that until now Entoloma sulcatum has been known only from Central America
its distribution could be significantly wider. This species is characterized by its sulcate-striate, slightly depressed pileus, clavate to broadly clavate cheilocystidia, pentagonal basidiospores, and hyphae which lack clamp connections. The presence of some quantities of 6—7 angled spores in our collection points towards a resemblance to Alboleptonia flavifolia T. J. Baroni et Lodge, which, however, has larger (up to 16 mkm long) spores. Entoloma proprium E. Horak from New Caledonia is similar with its clavate cheilocystidia but differs by smaller spores and encrusted hyphae of the pileipellis.