Amanita aureofloccosa Bas, Persoonia
Creators: name: Liu, Yuan S.
name: Kumla, Jaturong
name: Suwannarach, Nakarin
name: Sysouphanthong, Phongeun
name: Lumyong, Saisamorn
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Agaricales
Amanitaceae
Amanita
Amanita aureofloccosa

description: Amanita aureofloccosa Bas, Persoonia 5: 384 (1969). Figure 1c and 4
Basionym: Lepiota aurea Beeli, Bull. Soc. Roy. Bot. Belg. 59: 105. 1927; non Amanita aurea (Beeli) E. J. Gilbert, Iconogr. Mycol. 27: 205. 1941 (= Amanitopsis aurea Beeli, Bull. Soc. Roy. Bot. Belg. 63: 108. 1931).
Basidiomata large. Pileus 10.5–13.9 cm diam., plano-convex to applanate at maturity; volval remnants on pileus fibrillose to floccose or somewhat pulverulent, vivid yellow (3A8) to yellow (3B8), densely arranged on the disk; margin non-striate, appendiculate; context white (1A1), unchanging. Lamellae free, crowded, white (1A1); lamellulae attenuate with some subtruncate. Stipe 16.2–24.5× 1.8–2.1 cm, cylindrical and slightly tapering upwards, covered by vivid yellow (3A8) to yellow (3B8), floccose and somewhat pulverulent scales; context fistulose, white (1A1); basal part slightly inflated, fibrillose to floccose, light yellow (1A5) to vivid yellow (3A8) volval remnants. Annulus apical, fragile, sub-membranous, vivid yellow (3A8) to yellow (3B8). Odor not recorded.
Lamellar trama bilateral. Mediostratum 10–15 μm wide, composed of abundant sub-cylindrical inflated cells (40–62 × 8–15 μm); filamentous hyphae abundant to dominant, 1–10 μm wide; vascular hyphae scarce. Lateral stratum 15–23 μm wide, composed of abundant clavate to sub-cylindrical inflated cells (20–53 × 8–15 μm), diverging at an angle of ca. 30° to 45° to mediostratum; filamentous hyphae abundant, 2–7 μm wide. Subhymenium 15–25 μm thick, with 1–3 layers of subglobose, or irregular cells, 6–12 × 5–11 μm. Basidia (Figure 4b) 33–53 × 11–15 μm, clavate, 4-spored; sterigmata up to 3–4 μm long; basal septa lacking clamps. Basidiospores (Figure 4a) [50/2/2] (8) 8.5–10 (10.5) × 7–9 (9.5) μm, avl X avw = 9.1 × 8.4 μm, Q = 1.0–1.19 (1.29) μm, Qm = 1.09 ± 0.07, globose to subglobose, sometimes broadly ellipsoid, amyloid, colorless, guttulate, thin-walled, smooth; apiculus small. Pileipellis composed of radial, thin-walled, yellowish white, filamentous hyphae 3–18 μm wide; vascular hyphae scarce. Volval remnants on pileus (Figure 4c) composed of yellowish white, interwoven to repent arranged elements: filamentous hyphae fairly abundant, 2–9 μm wide, thin-walled, branching, anastomosing; inflated cells very abundant to dominant, slenderly clavate to fusiform, 18–165 × 10–40 μm, thin-walled; vascular hyphae scarce. Volval remnants on stipe base is semblable with the structure of volval remnants on pileus, filamentous hyphae scattered, 4–6 μm wide, thin-walled, branching, anastomosing; inflated cells very abundant to dominant, ellipsoid, clavate to sub-cylindrical, 23–200 × 18–35 μm, thin-walled; vascular hyphae scarce. Stipe trama composed of longitudinally arranged, filamentous hyphae, 5–15 μm wide; vascular hyphae scarce. Clamps absent in all parts of basidiomata..
Habitat: Solitary to scattered on soil in subtropical semi-deciduous seasonal forest, tropical deciduous forest, and on the ground along a road, in slightly sun-exposed areas, April to September.
Distribution: This species is currently known in Brazil (Wartchow et al. 2015), Colombia (Palacio et al. 2015), Ghana (Pegler 1968; Wartchow et al. 2015), the Southern Democratic Republic of the Congo (Bas 1969), and Thailand (this study).
Specimens examined: THAILAND. Chiang Rai Province: Mueang District, N 20°02’29’’, E 99°49’47’’, alt. 435 m, 22 Jun 2020, Phongeun Sysouphanthong, PS-2020-38 (SDBR-STO-2020-PS38, GenBank accession no.: nrLSU = OM 980704, ITS = ON000811, RPB2 = ON007281, and TEF1 -α = ON007299); Phongeun Sysouphanthong, PS-2020- 39 (SDBR-STO-2020-PS39, GenBank accession No.: nrLSU = OM 980705, ITS = ON000812, RPB2 = ON007282, and TEF1 -α = ON007300); Chiang Mai Province: Mueang District, N 18°47’48’’, E 98°57’11’’, alt. 334 m, 11 Jun 2021, J. Kumla & N. Suwannarach, NK1470 (SDBR-CMUNK1470, GenBank accession no.: ITS = ON695871).
Remarks: Morphologically, Amanita aureofloccosa is unique among congeners by having a pulverulent, bright orange-yellow volva remnant on its pileus, a slender stipe covered by orange-yellow floccose scales, a globose to subglobose, amyloid basidiospore and the lacking clamps in all parts of basidiomata. According to the original literature (Bas 1969), the basidiospores size of A. aureofloccosa was described as 7–8.5 × 6.5–8.5 μm, but Wartcow et al. (2015) re-examined the lectotype (BR2229) and additional material from Ghana (K173243), and amended the basidiospores size to (6.5–) 6.8–10.5 (–10.8) × (6.5–) 6.8–10.2 (–10.5) μm, of which the results are similar to Thai material. Significantly, compared to the materials from other countries, our collections from Thailand have larger basidiomata and basidia.
description: Published as part of Liu, Yuan S., Kumla, Jaturong, Suwannarach, Nakarin, Sysouphanthong, Phongeun & Lumyong, Saisamorn, 2022, Three species of Amanita section Lepidella (Amanitaceae, Agaricales) from northern Thailand, pp. 16-28 in Phytotaxa 570 (1) on pages 23-24, DOI: 10.11646/phytotaxa.570.1.2, http://zenodo.org/record/7529863