Lepiota subvenenata Hai J. Li, Y.Z. Zhang & C.Y. Sun.
Index Fungorum number: IF 829580; MycoBank number: MB 829580; Facesoffungi number: FoF 09888; Figs. 1, 2
Pileus 30–50 mm diam., first subglobose, expanding to parabolic to convex or umbonate, plano-convex when mature, with straight margin; when young glabrous to granulose, completely light brown to brown (7D7-8), when mature surface breaking and leaving concolorous glabrous or granulose umbo, with concolorous squamules around umbo towards margin, on white to orange-white (5A2) background; margin with concolorous squamules and white partial veil remnants. Lamellae free, broadly ventricose, with 3 length lamellulae, up to 4 mm wide, white, crowded, with white eroded edge. Stipe 40–70×5–7 mm, cylindrical, with white fibrillose and light brown to brown (7D7-8) squamules at annular zone, with concolorous squamules under annular zone downwards base, on white to orange-white (5A2) background. Annulus an annular zone, with white fibrillose and concolorous squamules. Context in pileus white, 3–5 mm wide; in stipe hollow, concolorous with surface. Taste and smell unknown. Spore print white.
Basidiospores [50,1,1] 4.5–6.3 × 2.5–3.5 µm, avl × avw = 5.02 × 3 µm, Q = 1.7–1.8, Qav = 1.75, in side-view oblong ovoid, in frontal view oblong, slightly thick-walled, hyaline, dextrinoid, congophilous. Basidia 18–23 × 7–10 µm, clavate, slightly thick-walled, hyaline, 4-spored, rarely 2-spored. Cheilocystidia 13–25×6–10 µm, cylindrical to irregular cylindrical, narrowly clavate to clavate, sometimes fusiform or utriform, slightly thick-walled, hyaline. Pleurocystidia absent. Pileus covering a trichoderm made up of cylindrical elements with rounded or attenuate apex, 60–170×7–13 µm, thick-walled, with parietal pale brown and intracellular pigment. Stipe covering of squamules similar to pileus covering. Clamp connections present.
Material examined – Laos, Oudomxay Province, Xay District, Houay Houm Village, N 20° 32′ 00.67″, E 101° 53′ 48. 17.16″. 917 m., 25 July 2014, P. Sysouphanthong, PS2014- 1450 (HNL503121).
Habitat and distribution – Growing in a small group, on humus soil mixed with dead leaves; known from Yunnan province of Southwest China (Zhang et al. 2019). We report the first record of L. subvenenata from Laos in this study.
GenBank numbers – HNL503121–MT436258 (ITS).
Notes – Lepiota subvenenata was described from Yunnan province of Southwest China. It is closely related to L. venenata Z. H. Chen & Zhu L. Yang in morphology. Lao specimens clustered with the type specimens in the nrITS phylogenetic analyses and share similar morphology (Fig. 3).
Figure 1 – Lepiota subvenenata in habitat. a-e HNL503121
Figure 2 – Lepiota subvenenata (HNL503121, new record). a Basidiospores b Basidia c Cheilocystidia d Pileus covering
Figure 3 – Maximum likelihood phylogenetic tree based on nrITS sequences of Lepiota species. Bootstrap support≥70% is indicated at the nodes. New sequences from this study are in blue. The GenBank accession numbers are indicated after the species name. Abbreviation L=Lepiota, M=Macrolepiota. The tree is rooted in Macrolepiota orientiexcoriata