Lepiota pongduadensis Sysou., Hyde & Vellinga in Sysouphanthong et al., Cryptog. Mycol. 33(1): 37 (2012).
Index Fungorum number: IF 519961; MycoBank number: MB 519961; Facesoffungi number: FoF 09886 Figs. 1, 2
Pileus 30–45 mm, campanulate, expanding to convex or umbonate with small umbo, applanate with low umbo, straight margin; glabrous to rough at umbo, brown to dark brown (6E5-8, 7F7-8), with light brown to brown (7D6-8, 7E7-8) glabrous around umbo, later surface broken in radial streaks from around umbo towards the margin, with concolorous tomentose to crowded squamules towards the margin, on white to yellowish-white (4A2) black ground; marginal zone broken, split, fringed, cortinate with write bibrils and light brown to brown (7D6-8, 7E7-8) partial veil remnants. Lamellae free, slightly crowded, ventricose to broadly, 3–5 mm wide, with 2 length lamellulae, white to yellowish-white (4A2), with concolorous eroded edge. Stipe 35–45×4–6 mm, cylindrical, fibrillose or cortinate at middle zone, then with light brown to brown (7D6-8, 7E7-8) squamules downwards base, with white to yellowish-white (4A2) black ground from middle to apex, with reddish-white (7A2) below middle zone downwards base. Annulus an annular zone, cortinate with white fibrils. Context white and up to 3 mm wide in pileus; hollow and concolorous with surface. Smell and taste unknown. Spore print white.
Basidiospores [50,2,2] 11.5–16.5 × 4–5.5 µm, avl×avw =13.4×4.6 µm, Q =2.8–3, Qav=2.91, in sideview cylindrical amygdaliform, with attenuate apex, with straight abaxial side, with hilar appendage, with superhilar
depression, in frontal view fusiform, hyaline, slightly thick-walled, dextrinoid, congophilous. Basidia 16–26×7–9 µm, clavate, hyaline, thick-walled, 4-spored. Cheilocystidia abundant, 27–35×6.5–15 µm, mostly fusiform or clavate, sometimes utriform, thick-walled, hyaline. Pileus covering a trichoderm made up of narrowly cylindrical elements, normally wider at middle and narrow to apex, with attenuate apex 70–400×6–13.5 µm, thick-walled, with brown parietal and intracellular pigment, smooth, sometimes incrusted at base of element and hyphae. Stipe covering of squamules a trichoderm 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., 10 July 2014, P. Sysouphanthong, PS2014-1460 (HNL503131); ibidem, 12 August 2014, P. Sysouphanthong, PS2014-1479 (HNL503150).
Habitat and distribution – Growing solitary to a small group; saprotrophic and terrestrial on humus soil; originally described from northern Thailand (Sysouphanthong et al. 2012). This is the first report of L. pongduadensis in Laos.
GenBank numbers – HNL503131–MT436259 (ITS). HNL503150–MT436260 (ITS).
Notes – Lepiota pongduadensis is a new record from Laos; two Lao specimens were collected from Oudomxay Province of northern Laos, and they show similar morphology and nrITS sequences to the type specimen (Fig. 3). Lepiota pongduadensis was originally described from Chiang Mai and Chiang Rai Provinces of northern Thailand. The species is placed in the section Lepiota by Sysouphanthong et al. (2012) and is distinguished from other species in the section. Only a few species are similar to L. pongduadensis (Sysouphanthong et al. 2012). Lepiota attenuata, the type specimens from China, is similar to L. pongduadensis in morphology, but different in lacking a dark brown surface on umbo, lighter colour of squamules on pileus, and stipe covering (brownish-yellow to yellowish-brown), larger basidiospores (14.5–19×4–5.5 mm), shorter elements of pileus covering (80–231×3.8–13 mm) (Liang et al. 2011).
Figure 1 – Lepiota pongduadensis in habitat. a-b HNL503131 c HNL503150
Figure 2 – Lepiota pongduadensis (HNL503131, new record). a Basidiospores b Cheilocystidia c 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