Agaricales » ‎Agaricaceae » Agaricus

Agaricus badioniveus

Agaricus badioniveus Linda J. Chen, R.L. Zhao & K.D. Hyde

Facesoffungi number: FoF 02283.

Pileus 3.5 cm diam, 3 mm thick at disc; convex and truncated at disc; surface dry, with yellowish brown fibrils, densely at disc, and progressively sparse towards the margin, on a white background. Margin straight, not exceeding the lamellae, with appendiculate remains of the annulus. Lamellae free, crowded, 3 mm broad, with intercalated lamellulae, ventricose, pinkish to brown with time. Stipe 45 × 7 mm (12 mm at base), cylindrical with a bulbous base, surface above the ring smooth, below the ring fibrillose, white, strongly flavescent when bruised. Annulus simple, membranous, superous, white, fragile. Context firm, white, flavescent when cut. Odour of strong almonds.

Spores (5–)5.4–5.8(–6.2) × 3.1–3.5(–3.8) µm, (x = 5.6 ± 0.12 × 3.3 ± 0.11 µm, Q = 1.54–1.86, Qm = 1.67 ± 0.01, n = 20), ellipsoid, smooth, brown, thick-walled. Basidia 15–19 × 6.5–7 µm, clavate to broadly clavate, hyaline, smooth, 4-spored. Cheilocystidia 23–35(–40) × 9–12(–16) µm, abundant, simple, or septate at base, pyriform, clavate or narrowly clavate, with yellowish pigments, smooth. Pleurocystidia absent. Pileipellis a cutis constituted of cylindrical hyphae of 6–9 um wide, not or slightly constricted at the septa, with brownish pigment. Macrochemical reactions — KOH reaction positive, yellow. Schäffer’s reaction positive, reddish orange on dry specimen. (Figs. 1–2)

 

Etymology: Refers to the pileus with tawny fibrils on a white background.

Habitat: Solitary on soil, in forest.

Material examined:THAILAND, Chiang Rai Prov., Doi Pui site1, 25 July 2012, J. Chen, LD2012131 (holotype MFLU12-0964).

   Notes: Agaricus badioniveus is characterized by a pileus surface covered with yellowish brown fibrils, simple cheilocystidia and spores on average size of 5.6 × 3.3 μm. In gross morphology, A. badioniveus is highly similar to A. megalosporus. However, the latter species has larger sporocarps (the pileus diameter can reach 10 cm) and spores (6 × 3.5 μm on average). According to phylogenetic results, A. badioniveus is closely related to A. flammicolor, a species easily distinguished by its bright orange colour.

 

Fig 1. Agaricus badioniveus (holotype LD2012131). a. Pileus surface; b. lamellae and stipe.

 

Fig 2. Agaricus badioniveus (holotype LD2012131). a. Cheilocystidia; b. basidia; c. basidiospores. — Scale bars: c = 10 µm, d–e = 5 µm.

 

 

 

 

 

Reference

Chen J, Callac P, Parra LA, Karunarathna SC, He MQ, Moinard M, ... & Zhao RL 2017 Study in Agaricus subgenus Minores and allied clades reveals a new American subgenus and contrasting phylogenetic patterns in Europe and Greater Mekong Subregion. Persoonia: Molecular Phylogeny and Evolution of Fungi, 38, 170.

 

About GMS Mushrooms

The webpage Gmsmushrooms.org 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).

Contact



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