Macrolepiota dolichaula (Berk. and Broome) Pegler and Rayner
Index Fungorum number: IF 333540; Facesoffungi number: FoF 09699.
Pileus 75–175 mm, first subglobose to globose, soon expanding to campanulate, um-bonate with high umbo, with inflexed margin, with brownish-orange to light-brown (6C5–6, 6D6–7) glabrous surface and smooth when young, soon surface radially broken from mar-gin to center, with light-brown (6C5–6, 6D6–7) radially crowded squamules around central calotte toward margin; squamules fragile and distant or completely disappearing when ma-ture, on white fibrillose background; marginal zone with white fibrils, sulcate when mature. Lamellae free, white, crowded, ventricose, wider at pileus margin and narrow to pileus center, 20–28 mm wide. Stipe 140–260 10–15 mm, cylindrical, white background, white and smooth from apex to the middle, covered with orange-white to pale-orange (5A2–3) minute squamules downward base, turning pale-red to pastel (7A3–5) when touched, with crowded white rhizomorphs at the base. Annulus membranous, descendent, white on the upper side, with concolorous squamules underside as those on pileus, moveable when mature. Context, white and moderately thick in pileus, white and hollow in the stipe, slowly turning pale-red to pastel (7A3–5) in both pileus and stipe. Taste and smell note observed. Spore print whitish to white.
Basidiospores [100,4,4] 12.5–15 8.5–11.5 m, avl avw = 13.86 10.2 m, Q = 1.31–1.5, avQ = 1.37, ellipsoid-ovoid, ellipsoid, to ellipsoid-amygdaliform in the side view, ellipsoid in frontal view, hyaline and thick-walled, with germ pore and hyalinous cap over germ pore, dextrinoid, congophilous, cyanophilous, metachromatic. Basidia 30–45 10–15 m, clavate, hya-line, and thin-walled, 4-spored. Lamella edge sterile. Cheilocystidia 20–30 10–14 m, clavate, rarely spheropedunculate, slightly thick-walled, hyaline. Pleurocystidia absent. Pileus covering a hymeniderm made up of oblong to cylindrical elements, terminal elements oblong, cylindrical, short clavate, with rounded or attenuate apex, 15–55 6–9 m, hyaline to pale-brown parietal pigment. Stipe covering not observed. Clamp-connections are present and abundant at the base of basidia and cheilocystidia.
Habitat and distribution: saprotrophic and terrestrial growing in grasslands, un-der shade trees beside grassland, in pine forests, and on cow dung; solitary or with many basidiomata spread over a wide area; widely distributed and found throughout northern Thailand.
Material examined: Thailand, Chiang Rai, Muang District, Mae Fah Luang University Campus: 20 03016.900 N; 99 53042.600 E, alt., 410 m, 7 August 2011, P. Sysouphanthong, 2011-15 (MFLU 12-1816); Chiang Rai, Muang District, Pong Phra Bath Village, 15 July 2012, P. Sysouphanthong, 2012-1 (MFLU 12-1764); ibidem, 20 August 2012, P. Sysouphanthong, 2012-13 (MFLU 12-1776); ibidem, 27 August 2012, P. Sysouphanthong, 2012-15 (MFLU 12-1778); Chiang Rai, Muang District, Mae Pu Ka Village, 14 June 2009, K. Anchalee, BJP020, culture (MFLUCC 10-0366); ibidem, 9 July 2009, K. Anchalee, BJP0046 (MFLU 12-1782); Chiang Rai, Mae Fah Luang District, Mae Salong Nok Village: 20 090121.700 N; 99 39026.6 00 E, alt., 985 m, 22 July 2012, P. Sysouphanthong, 2012-8 (MFLU 12-1771); Chiang Mai, Mae Taeng District, Pha Deng Village: 19 06049.100 N; 98 43033.500 E, alt., 971 m, 16 June 2009, P. Sysouphan-thong, BJP017, culture (MFLUCC 10-0363). Laos, Xiang Khouang Province, Pek District, Mak Khay Village, 8 June 2016, P. Sysouphanthong, PS2016-81 (HNL503204); Champasak Province, Pak Song District, 3 October 2015, P. Sysouphanthong, PS50 (HNL503277).
Notes: All specimens of M. dolichaula are characterized by large basidiomata, a pileus with small, brownish-orange to light-brown, crowded squamules on a white fibrillose background, a long stipe with pale-orange minute squamules, and membranous annulus attached at the upper part of stipe, ellipsoid to ellipsoid-amydaliform spores with germ pore and cap, clavate cheilocystidia, and oblong to cylindrical elements in the pileus covering. This species is widespread all through tropical Asia and has been reported from Sri Lanka, India, and Vietnam, both tropical and temperate China, Laos, and is also known from Australia. Macrolepiota dolichaula is common in Thailand, and it was also recorded from Laos by Læssøe et al., however, these studies were based on macromorphology only. Thus, we redescribe this species based on morphology and molecular evidence. The nrITS sequences from Thailand and Laos group with specimens from China and Australia with high bootstrap support. Macrolepiota aberdarensis Mbaluto and Otieno, a close relative from Kenya, does not differ much from M. dolichaula in morphology and nrITS sequences analysis. However, a multiple genes analysis is required to verify both species. It is well possible that the species recorded by Pegler and Rayner from East Africa is M. aberdarensis, and not M. dolichaula proper. One should also note that M. abararensis was not validly published as a herbarium for the type collections was not indicated.
Fig. 1 Maximum parsimony tree of Macrolepiota Bootstrap values for maximum likelihood equal to or greater than ≥60 and Bayesian posterior probabilities ≥0.95 are placed above the branches. Abbreviations are as follows: La. = Leucoagaricus, L = Lepiota, and M = Macrolepiota. All taxon names in bold are new sequences in this study. Leucoagaricus meleagris (Gray) Singer and Lepiota cristata (Bolton) P. Kumm. are used as outgroup. Country, type, and GenBank accession number are indicated after each species name.