Marasmius conicopapillatus Henn., Bot. Jb.

Shay, Jackie E., Desjardin, Dennis E., Perry, Brian A., Grace, Chris L. & Newman, Danny S., 2017, Biodiversity and phylogeny of Marasmius (Agaricales, Basidiomycota) from Madagascar, Phytotaxa 292 (2), pp. 101-149 : 116

8. Marasmius conicopapillatus Henn., Bot. Jb. 22: 100. 1895. ( Fig. 5 , Plate 2 )

Type:— CAMEROON. Ekundu–Liongo, 20 May 1892, P. Dusén 41 ( UPS).

Description:— Pileus 1–4 mm diam, convex to plano-convex, umbilicate, with prominent dark brown conical papilla; margin sulcate; surface dull, dry, glabrous; white at margins becoming tan to cream towards disk. Context thin (<1 mm), buff. Lamellae adnate to a collarium, distant (11–12), no lamellulae, ventricose, buff to cream (5 A 2), non-marginate. Stipe 2–9 × <0.5 mm, central, wiry, pliant, hollow; surface glabrous; initially white darkening to light brown or brown (6 E 8) at the base. Odor and taste not distinctive.

Basidiospores (7.2–) 8–9.6 × (3.8–) 4–4.4 μm [x m = 8.50 ± 8.4 × 4.02 ± 0.12 μm; Q = 1.36–2.40; Q m = 2.11 ± 0.18, n = 25, s = 1], ellipsoid, smooth, hyaline, inamyloid, thin-walled. Basidia 19.2–28 × 4.8–6.4 μm, clavate, 4-spored, hyaline, inamyloid, thin-walled; sterigmata 3.2–4.8 × 1.6 μm. Basidioles 12–29.6 × 3.3–5.6 μm, clavate, hyaline, inamyloid, thin-walled. Cheilocystidia of Siccus - type broom cells; main body 9.6–16 × 7.2–8 μm, clavate to subglobose or irregular, seldom lobed, hyaline, inamyloid, thin-walled; apical setulae 0.8–2.4 × 0.8 μm, cylindrical, hyaline, inamyloid, thin-walled. Pleurocystidia absent. Pileipellis not mottled, a hymeniform layer of Siccus- type broom cells; main body 7.2–20 × 4.8–10.4 μm, clavate to subglobose, seldom lobed, hyaline, inamyloid, thick-walled; apical setulae 0.8–3.2 × 0.8 μm, cylindrical, hyaline, inamyloid, thick-walled. Pileus trama interwoven; hyphae 3.2–14.4 μm diam, cylindrical to inflated, smooth, hyaline, inamyloid, thin-walled. Lamellar trama regular; hyphae 2.4–6.4 μm diam, cylindrical, hyaline, inamyloid, thin-walled. Stipe tissue monomitic; cortical hyphae 3.2–8.8 μm diam, cylindrical to slightly inflated, smooth, hyaline, dextrinoid, thick-walled; medullary hyphae 0.8–22.4 μm diam, cylindrical to inflated, smooth, hyaline, inamyloid, thin-walled. Caulocystidia absent. Clamp connections present.

Habit, habitat and known distribution:—Gregarious, in clusters on leaves of Eugenia (dicot, Myrtaceae ). Africa ( Burundi, DR Congo, Cameroon, Ghana, Ivory Coast, Nigeria, Uganda, Sierra Leone), Indonesia (Java), Madagascar.

Material examined:— MADAGASCAR. Region Alaotra-Mangora, District Moramanga, Commune Andasibe, Vohimana Forest, Piste 5, elev. 820–860 m, GPS: 18˚ 55.422’ S, 48˚ 30.201’ E, 26 January. 2014, J. E. Shay 180 ( SFSU).

Notes:— Marasmius conicopapillatus is distinguished by small (1–4 mm diam), sulcate, umbilicate pileus with a prominent dark brown conical papilla and initially white margin that develops tan to cream tones in age, distant (11–12) non-marginate collariate lamellae, a short stipe initially white to cream and becoming brown in age, basidiospores with mean 8.5 × 4 μm, Siccus - type cheilocystidia and pileipellis broom cells, and growth on dicotyledonous leaves. The Madagascar specimen ( JES 180) matches nicely the description of African material by Antonín (2007). Unfortunately, repeated attempts to obtain an ITS sequence were unsuccessful.

Figures

PLATE 2. Basidiocarps representing sect. Marasmius subsect. Sicciformes a) Marasmius conicopapillatus (JES 180) b) Marasmius aff. curreyi (JES 135) c) Marasmius rubrobrunneus (JES 183). Scale bar = 5 mm (a); = 10 mm (b, c). Photography by D.S. Newman.

FIGURE 5. Marasmius conicopapillatus (JES 180) a) basidiospores; b) basidia; c) basidioles; d) cheilocystidia; e) pileipellis cells. Scale bar = 10 μm. Illustrated by J.E. Shay.