Amanita altipes Zhu L. Yang, M. Weiss & Oberw.
Facesoffungi number: FoF04857
Basidiomes medium-sized. Pileus 70 mm in wide, parabolic when young, convex to plano-convex, depressed at centre, broadly umbonate, yellowish to yellow (3A4–7), pale yellow toward margin, often with dark yellow to brownish (5D6–8) over disk, viscid when moist; universal veil mostly over disc as felty, floccose patches, 2–5 mm wide, thick, yellowish to yellow to dirty yellow (3A2–5); margin tuberculate-striate (0.13–0.41R), non-appendiculate. Lamellae 2–4 mm broad, free to nearly free, crowded to plentiful, white to yellowish (2A1–3); lamellulae of 2–5 lengths, crowed, truncate; context white, hollow in centre. Stipe 150 × 16 mm. (length includes bulb), with tapering upward, yellowish (3A2–4), becoming whitish toward stipe base, often covered with yellow to yellowish (3A4–6) squamules above partial veil, white, with yellowish to whitish squamules or fibrils under partial veil, white (1A1). Bulb subglobose to ovate, 8–32 mm diam., white. Universal veil on stipe base as very short volval limb on bulb margin, floccose patches or warts near apex of bulb, yellow to yellowish (3A6–8). Partial veil subapical, membranous, 18 mm below apex of stipe, surface yellowish, with a yellow edge. Odour indistinct. Lamellar trama bilateral, divergent; mediostratum 50–60 μm wide; filamentous hyphae 1.8–8 μm wide, branching, hyaline, of abundant fusiform to subellipsoid, inflated cells (60–90 × 12–33 mm); vascular hyphae not observed. Subhymenium 30–50 μm thick; inflated cells dominating, in 2–3 layers, ovoid to subellipsoid, 10–25 × 8–18 μm, subtended by concatenated partially inflated hyphal segments. Basidia 32–70 × 10–14 μm, narrowly clavate to clavate, mostly 4-spored, occasionally 2-spored, with sterigmata up to 7 μm long; clamps absent. Basidiospores [60/1/1] (7.5–)8–10(–11) × (7–)7.5–9.5(–10) μm, (Q = 1–1.1(–1.2); Q’= 1.07 ± 0.06), smooth, hyaline, colourless, thin-walled, inamyloid, globose to subglobose, rarely broadly ellipsoid, apiculus rather variable, sublateral, very prominent to rather small, cylindric to truncate-conic; contents monoguttulate or occasionally granular; white in deposit. Lamellar edge sterile; filamentous hyphae 3–7 μm wide, hyaline, colourless or pale yellow, thin-walled; inflated cells dominating, mostly globose to subglobose and sometimes ovoid, 15–25 × 10–18(–24) μm, colourless, thin-walled. Pileipellis up to 155 μm thick; upper layer (70–130 μm thick) strongly gelatinized, composed of interwoven, thin-walled, colourless, filamentous hyphae 3–8 μm wide; lower layer (50–65 μm thick) composed of compactly arranged, filamentous hyphae 3–8 μm wide; vascular hyphae rare. Universal veil on pileus filamentous hyphae 2.5–6.2 μm wide, branching, with slightly inflated elements; inflated cells very abundant to nearly dominant, globose to subglobose to ovoid or ellipsoid to subfusiform (45–90 × 15–30 μm), in chains of 2–4, thin-walled, colourless vascular hyphae occasional. Universal veil on stipe base composed 5–6 irregularly arranged elements; filamentous hyphae very abundant 2.2–15 μm wide; inflated cells abundant to very abundant, fusiform to long ellipsoid, 40–80 × 10–35 μm, colourless or with intracellular pale brown pigment, thin- to slightly thick-walled, terminal or in chains of 2–3 and then terminal, becoming rare toward inner layer; filamentous hyphae abundant; vascular hyphae occasional. Stipe trama longitudinally acrophysalidic; filamentous hyphae 2.2–14 μm wide; acrophysalides subfusiform to clavate, 250–450 × 25–40 μm; vascular hyphae rare. Partial veil filamentous hyphae 2–5 μm wide, gelatinized, branching, hyaline, inflated cells terminal, thin-walled, ellipsoid to long ellipsoid, 15–70 × 10–24 μm, colourless, or with intracellular pale brown pigment, thin-walled; vascular hyphae rare. Clamp connections absent in all parts of basidiomes.
Material examined: THAILAND, Lampang Province, Along road number 1252, 18.935, 99.390833, elev.1450 m, 14 June 2013, B. Thongbai, BZ201342 (MFLU 14-0065).
Host and habitat: Solitary in forests dominated by Fagaceae.
Distribution: Known from China and Thailand.
Notes: Amanita altipes, originally described from southwestern China by Yang et al. (2004), resembles several species in the section Amanita, such as A. elata (Massee) Corner & Bas, A. gemmata (Fr.) Bertillon, A. orientigemmata Zhu L. Yang & Yoshim. Doi, A. russuloides (Peck) Sacc., and A. xylinivolva Tulloss et al. Amanita altipes shares some morphological similarities with these yellow to yellowish species which have been discovered in either Europe or Asia. Molecular analyses indicate that A. altipes is a distinct species closely related to A. melleialba. The combined gene phylogenetic analyses indicate that Thai A. altipes sequences clustered with A. altipes sequences from China with 100% ML support (Fig. 1).
Fig. 1 Phylogenetic tree of Amanita species inferred from a combine LSU and RPB2 sequence dataset using maximum likelihood. Bootstrap values (BS) C 50% are shown above the branches. The first records of Amanita species from Thailand in this study are in blue font. Voucher collection identifiers are provided after each species name. Type specimens are indicated in bold