Agaricales » ‎Agaricaceae » Agaricus

Agaricus armandomyces

Agaricus armandomyces M.Q. He & R.L. Zhao

Fungal Names: FN570353; Faceoffungi Number: FoF 02928

Pileus 16–42 mm in diam., convex first, plane with age, disc umbonate, or truncate umbonate, margin decurved when young, then straight with age, slightly exceeding; surface dry, covered by fibrils at the whole cap, forming fibrillose scales, light brown, ochre, or reddish brown, dense at disc and scattered towards the margin; background white or light yellow. Context 4 mm thick, flesh, white at pileus and yellowish brown at stipe. Lamellae 5–6 mm broad, free, crowded, broad, first white, pink or pinkish brown, then brown, edge even, intercalated with lamellulae. Annulus up to 3 mm in diam., fragile, membranous, single, white, pendant, smooth at both sides. Stipe 38–40 × 3–5 mm (6–7 mm at base), cylindrical, sometimes with a swallow base, hollow, surface dry, white, fibrillose below the annulus. Odour of almonds. Basidiome flavescent, orange when touching and bruising. Context turning flavescent first, then brown on exposure after few minutes. KOH reaction: positive yellow. Schäffer’s reaction: positive, reddish orange on dry specimen. Basidiospores 4.7–5.3 × 3.2–3.7 μm, [x = 4.9 ± 0.2 × 3.4 ± 0.1, Q = 1.4–1.6, Qm = 1.4 ± 0.0, n = 20], ellipsoid, smooth, thick-walled, brown. Basidia 15.7–21.2 × 6.2–8.0 μm, clavate, hyaline, 4-spored, smooth. Cheilocystidia 16.2–40 × 8.2–16.7 μm, smooth, pyriform mostly, broadly clavate and capitate with long narrow stipe, occasionally septate at the base with the cylindrical terminal element, hyaline. Pleurocystidia absent. Pileipellis a cutis composed of hyphae of 4.2–8.2 μm in diam., smooth, cylindrical, brown, slightly constricted at septa in some cases.

Habitat: solitary or scattered on soil in artificial forest which is dominant by Pinus armandii Franch.

Other specimens examined: Ludian County, Zhaotong, Yunnan Prov., China, alt. 2000–3000 m, 2 August 2015, collected by Zhao Rui-Lin, ZRL2015999 (HMAS275769); same location, 2 August 2015, collected by Su Sheng-Yu ZRL2015991 (HMAS275770); same location, 2 August 2015, collected by He Mao-Qiang, ZRL2015998 (HMAS275771), ZRL20151023 (HMAS275789), ZRL2015997 (HMAS275767); Tahe County, Great Hinggan, Heilongjiang Prov., China, 16 August 2015, collected by Li Guo-Jie, ZRL20151693 (HMAS275785).

Notes: The new species is represented by six specimens from Southwest and Northeast China under the support of 1.0/98 PP/BS values. In phylogeny, the clade of A. armandomyces is sister to A. kerriganii L.A. Parra, B. Rodr., A. Caball., M. Martín-Calvo & Callac, A. sp. (specimen WC912) and A. edmondoi L.A. Parra, Cappelli & Callac which are origin from Europe and West America in the clade I4 (Figs 1–2). In the morphology all of them have discoloration of distinct yellow on touching, similar basidiospores and cheilocystidia in size and shape. Even A. armandomyces are morphologically similar to the known species A. kerriganii and A. edmondoi, they can be molecular identified as different species. For example, there are six informative characters in ITS sequences between A. armandomyces, A. kerriganii (KF447893 from type specimen) and A. edmoindoi (KF447902 from type specimen) respectively.

Fig. 1 Maximum Likelihood (ML) tree of Agaricus section Minores based on LSU, tef1-α, rpb2 and ITS sequences with the outgroup Agaricus campestris. The Bayesian posterior probabilities and bootstrap support values more than 0.9/50% (PP/BS) are indicated at the nodes. The branches in Bold mean the related PP > 0.95. Sequences produced from this study are in blue. “T” refers to sequences from type specimen, and “T” in red refers to the sequences from type specimen and new to science from this study.






























Fig. 2 Morphology of Agaricus armandomyces (ZRL2015992, holotype), (A): Basidiome in field (ZRL2015992), (B): Cheilocystidia, (C): Basidiospores, (D): Basidia, and (E): Pileipellis hyphae.


He, M.Q., Chen, J., Zhou, J.L., Ratchadawan, C., Hyde, K.D. and Zhao, R.L., 2017. Tropic origins, a dispersal model for saprotrophic mushrooms in Agaricus section Minores with descriptions of sixteen new species. Scientific reports, 7(1), p.5122.



About GMS Mushrooms

The webpage provides an up-to-date classification and account of GMS Mushrooms


Supported by 
National Research Council of Thailand (NRCT) 

Project entitled:
“Total fungal diversity in a given forest area with implications towards species numbers, chemical diversity and biotechnology” (Grant no. N42A650547).


Published by the Mushroom Research Foundation 
Copyright © The copyright belongs to the Mushroom Research Foundation. All Rights Reserved.