Agaricales » ‎Agaricaceae » Lepiota

Lepiota pongduadensis

Pileus 19-35 mm, umbonate, expanding to capanlate, applanate with low umbo and straight margin, when young matted or glabrous, dark brown (6F7-8, 7F8) at umbo, brown (6E7-8, 7E7-8) around umbo to margin, this covering break open when mature, at umbo tomentose, felted to rough, dark brown to dark (7F4-5; 8F4), in radial streaks from umbo towards margin, with white surface in splits and yellowish-white (4A2) fibrillose background when mature, with brown (6E7-8, 7E7-8) squamules between splits or in radial streaks; marginal zone split or striate, fringed or fibrillose, exceeding lamellae. Lamellae free, moderately crowded, ventricose, 2.5-4.5 mm wide, cream-white, with white floccose edge. Stipe 32-55 × 2-3.2 mm, cylindrical, sometimes wider at middle and slightly tapering to apex and base, with subbulbous base, up to 4 mm wide, white from middle to apex, light brown (6D6-7) at middle zone and darker brown (7E6-7) down toward base, completely white fibrillose and floccose at middle zone to annular zone, squamulose from middle to base and with white to brown crowded squamules at base, hollow. Annulus an annular zone, white floccose or cortinate and brown squamulose. Context white to light brown (6D6-7) in pileus, in stipe

white at apex to middle, becoming brown (6E7-8) downward. Smell and taste not observed. Spore print white. Basidiospores [75,3,3] 13.0-16.0 × 4.5-5.5 μm, al × aw = 14.6 × 5.2 μm, Q = 2.2-3.2, Qav = 2.8, in side-view fusiform to amygdaliform, with or without confluent hilar appendage and with or without superhilar depression, in frontal view fusiform to subcylindrical, hyaline, thick-walled, dextrinoid, congophilous, cyanophilous, not metachromatic in Cresyl Blue. Basidia 18-30 × 8-10 μm, clavate, hyaline, slightly thick-walled, 4-spored. Lamella edge sterile, with crowded cheilocystidia. Cheilocystidia 20-30 × 8-13 μm, variable in shape, utriform, clavate or irregularly clavate, slightly thick-walled and colourless. Pleurocystidia absent. Pileus covering a trichoderm made up of narrowly cylindrical elements, mostly wider at middle and narrow at base and apex, 50-425 × 5-11.5 μm, slightly thick-walled and brown, with parietal and intracellular brown pigment, without short clavate elements, with cylindrical hyphae in under layer, smooth and rough- walled, 2.5-7.5 μm wide. Stipe covering of squamules a trichoderm with same structure as pileus covering. Clamp-connections present in all tissues. (Fig. 1)


MycoBank: MB 519961


Holotype: Thailand, Chiang Mai Prov, Mae Taeng Dist, Forest of Pong Duad Vill., N 16° 06’ 16.1”, E 99° 43’ 07.9”, 780-805 m alt., 22 June 2009, P. Sysouphanthong, MFLU100497.


Etymology: The name is derived from the first collecting site of this species close to Pong Duad Village.


Habitat: Growing solitary to a large group; saprotrophic and terrestrial on humus-rich soil, sandy soil with decaying leaves and wood; in deciduous mixed rain forest dominated by Castanopsis armata, Lithocarpus spp; only known from Northern Thailand.


Specimens examined: Thailand, Chiang Mai Prov., Mae Taeng Dist., Forest of Pong Duad Vill., N 16° 06’ 16.1”, E 99° 43’ 07,9”, 780-805 m, 8 August 2008, P. Sysouphanthong, MFLU090184; ibidem, 22 June 2009, P. Sysouphanthong, MFLU10 0497; Chiang Rai Prov., Mae Lao Distr., Forest of Khun Kon Waterfall, 22 July 2009, P. Sysouphanthong, MFLU100500.