Clavulina ruchengensis X.F. Liu & P. Zhang

Liu, Xiang-Fen, Deng, Peng-Tao, Wang, Xiao-Yan & Zhang, Ping, 2024, A new edible Clavulina species from Hunan Province, China, Phytotaxa 661 (2), pp. 169-180 : 173-176

Clavulina ruchengensis X.F. Liu & P. Zhang , sp. nov. ( Figs. 1 , 2 )

MycoBank:851419

Diagnosis:—Differs from Clavulina reae by having white to gray-white stipes, sharper branch tips, and shorter basidia.

Holotype:— CHINA. Hunan Province, Rucheng County. 28°6′12″N, 113°1′55″E, 400 m, 22 June 2020, leg. P. Zhang ( MHHNU10346 ).

Etymology:—ruchengensis refers to “Rucheng County” from where the holotype was collected.

Description:— Basidiomata coralloid, gregarious in caespitose clusters, 3–6 cm tall, 1–3 cm broad. Branching 2–6 times, flattened, dichotomous to polychotomous, ash gray when young, becoming gray [1B1–1C2] with age, branch tips sharply acuminate, cristate, deep brown [5F4]. Stipes clear, 0.8–3 cm long, subcylindrical or flattened, smooth, white to gray white [1A1–3C1]. Hymenium amphigenous, gray [1C2], basidiocarp surface occasionally with longitudinal corrugation. Odor is unapparent.

Basidiospores [75/6/3] (6.2–)6.5–9.2(–9.7) × (4.5–)4.8–7.2(–7.6) μm [Q = (1.00–)1.07–1.64(–1.82), Q m = 1.33 ± 0.15], subglobose to oblong-ellipsoid, smooth, thin walled, inamyloid, with a hilar appendix 0.4–1 μm long, with one or several oleiferous guttules nearly suffused with spores. Basidia (26–)29–43(–45.5)×4.8–6.8(–8) μm, clavate to subcylindrical, colorless and transparent, with numerous granular contents and guttules, basal clamps occasionally present, postpartal septa observed in some basidia; two sterigmata on per basidium, cornute, 3.2–6.2 μm long. Basidioles abundant, subclavate to subcylindrical, widespread among basidia. Tramal hyphae smooth, thin walled, up to 13 μm wide, some of the inflated tramal hyphae up to 19.8 μm wide; clamp connections abundant. Basidia and hyphae with oleiferous contents. Cystidia absent.

Habitat and distribution:—Gregarious in humus layers on soil under mingled forest, basidiomata occur in summer (June). To date, only known from Hunan Province in central China.

Additional materials examined:— CHINA. Hunan Province, Rucheng County. 28°6′12″N, 113°1′55″E, 400m, 22 June 2020, MHHNU10347, MHHNU10349.

Phylogenetic analyses

The alignment of concatenated sequences, which comprised 1,799 bp in total, was used for the BI and ML analyses. The matrix comprised 170 sequences (82 ITS and 88 nrLSU) representing 55 Clavulina taxa and two outgroup taxa ( Table 1 ). The BI phylogeny (not shown) was extremely similar in topology to that of the ML tree. Thus, only the ML tree is presented in Fig. 3 . Support values from the bootstrap analysis (BS) and posterior probabilities (PP) that were greater than or equal to 50% and 0.95, respectively, are shown at the relevant nodes. In both the ML and BI phylogenetic reconstructions, the three newly collected accessions formed a distinct, monophyletic lineage within the Clavulina clade. In combination with the distinct morphology of the accessions compared with all previously described species of Clavulina , it was concluded that the three accessions represented an unnamed species of Clavulina .

Figures

FIGURE 1. Basidiomata of Clavulina ruchengensis (a, b MHHNU10346). Bars = 1cm. Photos by P. Zhang.

FIGURE 2. Microscopic features of Clavulina ruchengensis (MHHNU10346). a Basidiospores. b Basidia. c Hyphae. Drawings by X.F. Liu.

FIGURE 3. Phylogenetic tree of Clavulina species inferred from the combined dataset (ITS and nrLSU) using ML Bootstrap (BS) ≥ 50%; Bayesian posterior probabilities (PP) ≥ 0.95 are reported nodes. “-” means the support value was less than the reported level. Scale bar: 0.07 substitutions. The new species are in bold.