Clavariadelphus alpinus J. Zhao & L.P. Tang, 2020

Huang, Hong-Yan, Zhao, Jie, Zhang, Ping, Ge, Zai-Wei, Li, Xian & Tang, Li-Ping, 2020, The genus Clavariadelphus (Clavariadelphaceae, Gomphales) in China, MycoKeys 70, pp. 89-121 : 89

publication ID	https://dx.doi.org/10.3897/mycokeys.70.54149
persistent identifier	https://treatment.plazi.org/id/C55B570F-668E-5939-BAAC-388E1485E720
treatment provided by	MycoKeys by Pensoft
scientific name	Clavariadelphus alpinus J. Zhao & L.P. Tang
status	sp. nov.

Treatment

1. Clavariadelphus alpinus J. Zhao & L.P. Tang sp. nov. Figs 2a View Figure 2 , 3a View Figure 3 , 4a View Figure 4 , 5a View Figure 5 , 6a, b View Figure 6

Diagnosis.

This species is distinguished from other taxa in Clavariadelphus by the light yellow, clavate basidiomes with enlarged apex, broadly ellipsoid basidiospores, hyphae of the basal mycelium with nipple-shaped protuberances and basidiomes turning lemon-chiffon in KOH.

Etymology.

Latin " alpinus " refers to this species occurring in high-altitude areas.

Description.

Basidiomes up to 12 cm high, 0.9 cm diam. at the base, enlarged upwards to 2 cm diam., simple, initially cylindrical to subcylindrical, then narrowly clavate to clavate, laterally compressed in age; hymenium initially smooth, then longitudinally rugose, light yellow (4A4-5) to yellow or yellowish-orange, apricot-yellow, light orange-yellow (4A6-7) or (5A5-6); apex subacute to obtuse, smooth to rugose, concolorous with the hymenium; surface not staining when cut or bruised; base terete, smooth, white to cream; mycelial hyphae white; flesh initially solid, then soft and spongy upwards as the apex enlarges, white not staining on exposure. Odour and taste not recorded. Spore deposit not recorded.

Hymenium extending over the apex of basidiomata, composed of basidia and leptocystidia. Basidia 65-85 × 8-10 μm, clavate, hyaline, thin-walled, (2-, 3-) 4-spored, sterigmata 8-12 μm in length. Basidiospores [20/1/1] (7.4-) 7.8-9.6 (-10.1) × 5.5 (-5.1)-7.4 μm, Q = 1.25-1.55 (-1.58), Q m = 1.38 ± 0.10, broadly ellipsoid, ovate or amygdaliform, with a small apiculus, inamyloid, thin-walled, hyaline in KOH, smooth. Leptocystidia 45-55 × 2.8-4.2 μm, scattered amongst and scarcely projecting beyond the basidia, cylindrical to narrowly clavate, thin-walled, smooth, hyaline, non-pigmented, clamped, inflated apically at maturity and at times, with apical or subapical branches. Mycelial hyphae 2-4 μm diam., interwoven or aggregated into rhizomorphic strands, branched, clamped; hyphal walls echinulate with light microscopy, covered with massive nipple-shaped protuberances without crystals with SEM.

Chemical reactions

(dried basidiomes). KOH = positive, lemon-chiffon; NH4OH = positive, orange; ethanol, FeCl3, FeSO4, Melzer’s reagent and phenol = negative.

Known distribution and ecology.

SW China, Yunnan Province. Solitary on the ground in forests dominated by conifers (e.g. Abies georgei ) at elevations of approximately 3700 m.

Materials examined.

China. Yunnan Province: Shangri-la Prefecture, Bita Lake, 24 August 2009, approximately 3700 m elev., B. Feng 667 (HKAS 57396, Holotype).

Comments.

Clavariadelphus alpinus is well characterised by its yellow basidiomes, broadly ellipsoid basidiospores, hyphae of the basal mycelium with nipple-shaped protuberances, the apex of the basidiomes having a positive reaction to NH4OH and KOH and distribution at high elevations in SW China in association with conifers.

Morphologically, this taxon is similar to C. khinganensis . However, C. khinganensis has light brown-tan basidiomes, more elongated basidiospores (Q = 1.6-2.2), negative reaction to NH4OH and distribution at lower elevations in NE China.

In the ITS phylogeny, this species is a sister species of C. truncatus with strong support (Fig. 1 View Figure 1 ). However, C. truncatus differs from C. alpinus by having dark coloured basidiomes from yellow to cinnamon-brown or brown, broader apices (up to 3.5 cm) and larger basidiospores (10.3-12.6 × 5.5-7.1 μm from neotype; Methven 1990).