Lepiota psalion Huijser & Vellinga, in Vellinga & Huijser, Belg. J. Bot. 131(2): 203 (1999) [1998]

Vizzini, Alfredo, Tatti, Alessia, Huijser, Henk A., Liang, Jun F. & Ercole, Enrico, 2019, Looking for Lepiotapsalion Huijser & Vellinga (Agaricales, Agaricaceae), MycoKeys 52, pp. 45-69 : 45

Lepiota psalion Huijser & Vellinga, in Vellinga & Huijser, Belg. J. Bot. 131(2): 203 (1999) [1998] Figs 3, 4, 5, 6

Description.

Macrocharacters (Fig. 3). Pileus 8-36 mm wide, at first slightly obtusely campanulate, hemispherical-trapezoid or broadly conical, later plano-convex to applanate-expanded, subumbonate, with a shallow umbo; not hygrophanous; margin not striated, slightly exceeding the lamellae when young, sinuous-undulate, entire or slightly fringed with age, with minute adhering remnants of partial veil when young; surface dry, at first smooth, later irregularly cracking around centre into concentric non-uplifted squamules; cream to pinkish-light brown at centre [*Vinaceous-buff (Plate XL 17 ’’’.c-y./d) HTML d3b094 to Orange-Cinnamon (Plate XXIX 13 ’’.ou-o.) or Ochraceous-Tawny (Plate XV 15'.y-o./i) HTML bc7e4d], paler towards the margin [Pale Cinnamon-Pink (Plate XXIX - 13 ’’.oy-o./f) HTML e5d6c3 to Pale Smoke-Gray (Plate XLVI 21 ’’’’.o-y./d) HTML cdc9c6]. Stipe 22-33 × 1.5-2 mm, central, cylindrical, usually regular, but sometimes also slightly flexuous, hollow; shiny, at first white, soon becoming pink-brown [Tilleul-Buff (Plate XL - 17 ’’’.c-y./f), HTML c3b092 to *Drab Gray (Plate XLVI 17 ’’’.o-y./d) HTML bda599] starting from the base and progressing upward; minutely silky fibrillose along all length; with whitish [Pale pinkish buff (Plate XXIX 17 ’’.o-y./f) HTML ede2d4], ascending and often incomplete annulus on the upper part of the stipe, sometimes disappearing in age; often with minute white rhizomorphs. Lamellae 2-3(4) mm wide, l = 1-3(4), free, crowded, at first white, soon with evident pinkish tints [Cream-Buff (Plate XXX 19 ’’.yo-y /d) HTML dfc38c to Clay-Color Plate (XXIX 17 ’’.o-y.) HTML ce9b44]; edge finely granulose. Context elastic, whitish, pink-brown towards the stipe base; without specific smell and taste. Spore-print pale cream.

Microcharacters (Figs 5, 6). Spores [700, 6, 2] (2.7 –)3.5–4.3(– 4.9) × (2.0 –)2.6–3.2(– 3.9) μm, on average 3.9 × 2.9 μm, Q = (1.03 –)1.23–1.49(– 1.78), Qav = 1.36, from broadly ellipsoid to ellipsoid, hyaline, thin-walled, smooth, not verruculose in Melzer’s reagent, binucleate, not metachromatic in Cresyl Blue, nonamyloid, non-dextrinoid, cyanophilic in Cotton Blue (Figs 5e, f, 6c). Basidia mainly 4-spored, (15.5 –)17.1–21(– 22.0) × (4.2 –)4.7– 5.8 (-6.0) μm (n = 54), rarely 1- or 2-spored, clavate, hyaline, thin-walled; sterigmata (2.6-) 3.0-4.2 (-4.9) × (0.5 –)0.6–1.1(– 1.2) μm (n = 67) (Fig. 6d). Lamella edge sterile. Cheilocystidia (10.0 –)13.7– 21.1 (-26.3) × (4.6 –)6.2–8.7(– 10.0) μm (n = 84), numerous and crowded, hyaline, thin-walled, various in shape, mostly clavate to subutriform, occasionally subfusiform, subcapitulate (Figs 5c, 6b). Pleurocystidia absent. Pileus covering a (140.7 –)153.7–179.1(– 201.1) μm (n = 16) thick hymeniderm with transition to an epithelium (Figs 5a,b, 6a), with up to 2(or 3) colourless elements on top of each other; terminal elements not tightly packed, (10.4 –)18.0–53.6(– 62.3) × (3.9 –)7.7–19.3(– 24.0) μm (n = 62), vesiculose, sphaeropedunculate to clavate-pyriform, utriform; slightly thick-walled (walls ca 0.5 μm), with walls embedded in a thin gelatinous matrix; subpellis composed of densely arranged and branching cylindrical hyphae, (21.3 –)49.0–108.5(– 136.8) × (3.8 –)4.5–8.8(– 9.7) µm (n = 38). Pileitrama of cylindrical hyphae, (33.1 –)42.1–93.2(– 111.8) × (2.7 –)4.3–9.8(– 14.4) µm (n = 45). Hymenophoral trama subregular, consisting of cylindrical hyphae (33.8 –)36.5–64.4(– 83.1) × (6.0 –)7.6–15.8(– 17.3) µm (n = 61). Stipe covering consisting of cylindrical hyphae, (23.8 –)80.1–214.4(– 370.8) × (2.6 –)5.4–12.1(– 15.4) µm (n = 58). Stipe trama consisting of cylindrical hyphae, (21.8 –)58.5–178.9(– 302.7) × (2.5-) 3.3 –11.6(– 12.5) µm (n = 32). Caulocystidia absent. Partial veil (annulus) composed of cylindrical elements, (21.1 –)27.5–52.7(– 94.7) × (2.2 –)2.9–4.8(– 8.5) µm (n = 36) with terminal clavate elements, (12.4 –)17.9–34.0(– 40.3) × (8.4 –)10.6–17.7(– 19.8) µm (n = 60) (Figs 5d, 6e). Clamp-connections present and abundant everywhere.

Ecology and distribution.

Gregarious on bare soil, in gardens and parks; so far known only from the type locality (Austria) and Sardinia (Italy).

Collections examined.

Italy, Sardinia, Cagliari, Botanical Garden, 6 basidiomes growing among the Searsia / Rhus sp. litter, calcareous soil, 17 January 2017, Alessia Tatti and Giacomo Calvia (CAG P.11_9/7.68). Austria, Wien-Lobau, N. Uferhaus, 23 August 1985, Anton Hausknecht (WU 5152, holotype) (Fig. 4).