Clavariadelphus pseudoelongatus P. Zhang & Z. H. Chen, 2025

Clavariadelphus pseudoelongatus P. Zhang & Z. H. Chen sp. nov.

Diagnosis.

Differs from other Clavariadelphus species in having ecru-drab to light purple drab basidiomata with age, becoming cinnamon after cutting or bruising.

Type.

China • Yunnan Province, Shangri-La Prefecture , 27°13'13"N, 100°02'20"E, 3828 m asl., 26 August 2020, leg. P. Zhang ( holotype MHHNU 32323 ) GoogleMaps .

Etymology.

Pseudoelongatus (Latin) refers to having longer basidiomata than other Clavariadelphus species, but differing from C. elongatus .

Description.

Basidiomata 6–14 cm tall, 0.7–0.9 cm in diameter, simple, narrowly cylindrical to clavate in age, erect or slightly flexuous, occasionally branched; hymenium longitudinally apparent rugose, ecru-drab (5 A 2–4) to light purple drab (12 D 3–12 D 4), slowly stained cinnamon (6 D 6) after cutting or bruising; apex fertile, smooth to rugose, obtuse to subacute with age, monochromatic with hymenium, rarely dark violet (16 F 8); base terete, almost smooth, white; context solid when young, gradually becoming soft and spongy in age. Odor and taste not recorded.

Hymenium extending over the apex of the basidiomata, composed of basidia and leptocystidia. Basidia 81–113 × 8–13 µm, narrowly clavate, pale yellow in KOH, smooth, thin-walled, clamped, 4 sterigmata (rarely 2), 8–15 µm tall, with numerous granular contents and guttules. Basidiospores [60 / 3 / 2] (9.2 –) 9.8–11.0 (– 13.0) × (6.0 –) 6.4–9.5 (– 11.0) µm [ Q = 1.16–1.55 (– 1.67), Q m = 1.31 ± 0.10], ellipsoid to broadly ellipsoid, with a prominent apiculus, and several oleiferous guttules within the spores, pale yellow in KOH, thin-walled, smooth, inamyloid. Leptocystida 31–71 × 2–6 µm, narrowly clavate, hyaline, smooth, clamped, with branches. Contextual hyphae 5–9 µm in diameter, thin-walled, clamped.

Ecological information and distribution.

Scattered or gregarious on the ground in the coniferous and broadleaved mixed forest in an elevational range of 3800–3828 m. Southwestern China.

Additional material examined.

China • Yunnan Province, Shangri-La Prefecture, Qianhu mountain , 27°25'45"N, 99°40'55"E, 3800 m asl., 24 August 2024 ( MHHNU 12123 ) GoogleMaps .

Comments.

Clavariadelphus pseudoelongatus can be distinguished by having longer and ecru-drab to light purple-drab basidiomata. It was initially misidentified as C. elongatus J. Khan, Sher & Khalid owing to the similar color of the basidiomata, which are light purple at maturity. In the phylogenetic analysis, C. pseudoelongatus and C. elongatus were respectively placed in different subclades based on molecular evidence. In addition, C. pseudoelongatus has broader basidiospores (9.8–11.0 × 6.4–9.5 µm vs. 9–11.0 × 5.7–7.4 µm) and larger basidia (81–113 × 8–13 µm vs. 75–95 × 6–10 µm) than C. elongatus .