Clavariadelphus miniatus P. Zhang & M. J. Li sp. nov.

Diagnosis.

Differs from other Clavariadelphus species in the small and pale yellow to salmon to purple-drab basidiomata with age.

Type.

China • Yunnan Province, Deqin Prefecture, 27°24'15"N, 98°57'55"E, 3750 m asl., 17 August 2018, leg. P. Zhang (holotype MHHNU 9952).

Etymology.

Miniatus (Latin) refers to the small basidiomata of this species.

Description.

Basidiomata 4–10 cm tall, 0.2–0.5 cm in diameter, simple, narrowly cylindrical to clavate with age, slightly flexuous when young, occasionally branched; hymenium initially smooth, longitudinally rugose at maturity, pale yellow (2 A 3) to salmon (6 A 4) to purple-drab (11 E 5); apex fertile, smooth to rugose, obtuse to subacute, occasionally truncated with age, monochromatic with hymenium; base terete, almost smooth, pale orange (5 A 3); context solid when young, gradually becoming soft and spongy with age. Odor and taste not recorded.

Hymenium extending over the apex of basidiomata, composed of basidia and leptocystidia. Basidia 72–120 × 10–13 µm, narrowly clavate, pale yellow in the KOH, smooth, thin-walled, clamped, 4 sterigmata (rarely 2), 6–12 µm tall, with numerous granular contents and guttules. Basidiospores [66 / 3 / 2] (16.5 –) 18.0–26.6 (– 27.0) × 4–6 (– 7.2) µm [Q = (2.75 –) 3.00–5.67 (6.50), Q m = 4.35 ± 0.79], ellipsoid to oblong, with a prominent apiculus, hyaline in the KOH, thin-walled, smooth, inamyloid. Leptocystida 30–82 × 3–4 µm, narrowly clavate, hyaline, smooth, clamped, with branches. Contextual hyphae 3–7 µm in diameter, thin-walled, clamped.

Ecological information and distribution.

Scattered or gregarious on the ground or on twigs in forest dominated by Picea in an elevational range of 3750–3800 m. Southwestern China.

Additional material examined.

China • Yunnan Province, Deqin Prefecture, Baima Snow Mountain, 28°15'28"N, 99°15'20"E, 3800 m asl., 19 August 2024 (MHHNU 12089).

Comments.

Unlike the other two new species identified in this study, C. miniatus is saprophytic and can be distinguished by the small size and pale yellow to salmon to purple-drab basidiomata. This taxon is confusable with C. sachalinensis. With regard to morphological characters and molecular sequence data, C. miniatus is similar to C. sachalinensis. Both species were resolved in a clade phylogenetically close to the two species of Lentaria, but their basidiospores are oblong, thin-walled, and hyaline in the KOH. Clavariadelphus sachalinensis has tawny or light walnut-brown to light brown basidiomata; thus, it is confusing to distinguish it from C. miniatus based on the color of the basidiomata alone. However, microscopic characteristics differ between C. miniatus and C. sachalinensis. Specifically, C. miniatus has longer basidiospores (18.0–26.6 × 4–6 µm vs. 21–24 × 4–6 µm) and basidia (72–120 × 10–13 µm vs. 65–105 × 8–12.5 µm).