Agaricales » ‎Agaricaceae » Lepiota

Lepiota microcarpa

Pileus 3.5-6 mm, convex, with small umbo, or umbonate to applanate, it straight to slightly inflexed margin, at center brown to red-brown (7E5-8, E5-6), glabrous to felted, densely fibrillose, or rarely with pyramid liked squa- ules, around umbo with irregularly concentrical squamules toward margin, squa- ules distant or absent at margin, squamules brown (7E5-8) on white fibrillose background; margin white fibrillose to cordinate, sulcate or fringed, exceeding lamellae. Lamellae free, sub-distant to slightly crowded, broadly ventricose, 0-3 mm wide, white with white eroded edge. Stipe 8.5-20 × 0.8-1.2 mm, cylindrical, covered with white fibrils, crowded at annular zone downward base, on light brown (6D5-6) background, with or without brown (7E5-8) squamules at base zone. Annulus an annular zone, cortinate or fibrillose, white. Context in ileus thin, white to light brown, less than 1 mm wide; in stipe concolorous with urface, hollow. Taste and smell not observed. Spore print white. Basidiospores [75,3,3] 10.8-16.5 × 4.0-5.3 µm, avl × avw = 13.5 × 4.7 µm, Q = 2.5-3.6, avQ = 2.9, in side-view with more or less straight abaxial side, strongly inflexed above hilar appendage (‘penguin-shaped’), in frontal view fusiform to cylindrical, hyaline and thick-walled, dextrinoid, congophilous, cyanophilous, not etachromatic in Cresyl Blue. Basidia 18-23 × 8.2-10.5 µm, narrowly clavate, 4- pored. Lamella edge sterile. Cheilocystidia 15.5-30 × 6.5-12.5 µm, mostly fusiform utriform, clavate to narrowly clavate, hyaline and thin-walled. Pleurocystidia absent. Pileus covering a trichoderm made up of narrowly cylindrical elements, arrow and tapering to apex, curved at base of elements, 62-240 × 10-12.5 µm, rown and thin-walled, with brown parietal and intracellular pigments, with short lavate elements, 8.5-37.5 × 4.5-12.5 µm, brown and slightly thick-walled; under ayer with hyaline to pale brown hyphae, up to 4.5 µm wide. Stipe covering of quamules at base a trichoderm similar to pileus covering. Clamp connections resent in all tissues. (Fig. 1)


MycoBank: MB 519962


Holotype: Thailand, Chiang Rai Prov., Mae Fah Luang District, Forest of Doi Tung, 10 June 2009, P. Sysouphanthong (MFLU 100491).


Etymology: named because of its tiny basidiomata.


Habitat: growing solitary or on a small group, mostly on umus-rich soil; under shade of deciduous forest dominated by Dipterocarpus spp. r in forest of Pinus kesiya. Found in rainy season (June to October) of moun- ainous areas of Northern Thailand.

Specimens examined: Thailand, Chiang Rai Prov, Mae Fah Luang Dist., Forest of Doi Tung, 10 June 2009, P. Sysouphanthong (MFLU100491) (Holotype). Chiang Mai Prov., Mueng Dist., Forest of Doi Suthep, N 18°48.62’, E 98° 54.60’ 1455 m. alt, 6 June 2010, P. Sysouphanthong (MFLU100521), ibidem, 12 June 2010, P. Sysouphanthong (MFLU 100526).