Clavulina griseoviolacea Yue Gao, Hao Zhou, & C. L. Hou, 2024

Gao, Yue, Tong, Xin, Zhou, Hao, Wang, Hai-Qi, Li, Cheng & Hou, Cheng-Lin, 2024, Three new species of the genus Clavulina (Hydnaceae, Cantharellales) from North China based on morphological and phylogenetic analysis, MycoKeys 108, pp. 75-94 : 75-94

Clavulina griseoviolacea Yue Gao, Hao Zhou, & C. L. Hou sp. nov.

Figs 2 D – E , 3 D , 5

Diagnosis.

Clavulina griseoviolacea differs from known Clavulina species in its gray to dark grayish violet basidiomata, with a white stipe, monopodial or irregularly polychotomous branches toward branch apices, basidiospores 6.5–8.0 × 6.2–7.2 μm, basidia 31.3–49.8 × 4.5–7.2 μm, postpartal septa present, and clamp connections present.

Etymology.

The epithet “ griseoviolacea ” refers to the basidiomata being gray to dark grayish violet.

Type.

China • Tianjin, Jizhou District, Jiulongshan ; 40 ° 8 ' 51 " N, 117 ° 30 ' 36 " E, alt. 170 m; 21 Aug. 2022; H. Zhou, X. Y. Shen & X. B. Huang ( BJTC ZH 0998 ); GenBank nrITS: PP 835334 , nrLSU: PP 835347 , rpb 2: PP 889520 .

Description.

Basidiomata coralloid, solitary or scattered; individual basidiomata 25–45 mm tall, 12–20 mm wide across branches, basidiomata sparsely branched two to three times, monopodial or irregularly polychotomous toward branch apices and dichotomous at the base, branches subclavated to fattened and somewhat flattened with age, rough, with rounded tips; gray (# a 5 a 5 a 5) to dark grayish violet (# 9 b 92 a 6) when fresh and tips somewhat very dark brown (# 1 f 1605), dark brown (# 4 c 350 b) when dry. Stipes generally distinct, 10–20 mm long, 2–5 mm wide, subcylindrical or flattened, dark gray (# 777777) to dark grayish purple (# 7 a 747 f) and sometimes with a white base (# ffffff). Hymenium amphigenous, generally nodulosus and farinaceous.

Basidiospores [65 / 2 / 1] 6.5–8.0 (- 8.6) × (5.9 -) 6.2–7.2 (- 7.9) μm, Q = 1.00–1.23 (- 1.27), Q m = 1.12 ± 0.06, globose to subglobose, smooth, hyaline in H 2 O and KOH, thin-walled, inamyloid, with a 0.6–0.9 μm irregular hilar appendix, and one large oleiferous guttule. Basidia (29.3 –) 31.3–49.8 (- 65.3) × 4.5–7.2 (- 8.3) μm, clavate to subcylindrical, tapering from apex to base; postpartal septa present in most basidia, occurring 12–24 μm below basidia tips; two sterigmata occur per basidium, 3.8–6.7 μm long, and cornute. Basidioles abundant, subclavate to subcylindrical. Tramal hyphae in stipe smooth, with slightly thickened walls, hyaline in KOH, 2.6–5.5 μm wide, some tramal hyphae inflated; tramal hyphae in branch hyaline, thin-walled, 3.7–6.1 (- 8.9) μm wide; clamp connections abundant. Hyphal system monomitic. Cystidia absent.

Habit, habitat, and distribution.

Solitary or scattered humus layers on soils under Theropencedrymion, associated with Pinus L. Basidiomata generally occurring from July to August; currently known from Tianjin and Beijing, China.

Additional specimens examined.

China • Beijing, Mentougou District, Baihua Mountain ; 39 ° 47 ' 50 " N, 115 ° 33 ' 35 " E, alt. 1,223 m; 16 Aug. 2023; H. Zhou, Y. Gao & X. Tong ( BJTC ZH 1653 ) .

Notes.

C. griseoviolacea is phylogenetically closely related to Clavulina cinerea , Clavulina iris var. occidentalis and Clavulina iris var. iris according to phylogenetic analyses (Fig. 1 .), but Clavulina cinerea has lilac-gray to gray basidiomata, larger basidiospores (7–10 × 6–8 µm) and basidia (38–65 µm long up to 7 µm wide) ( Burt 1922); Clavulina iris Loizides, Bellanger & P. - A. Moreau can be distinguished by its white-pruinose basidiomata, branches sometimes partially or extensively fused, larger basidiospores (9.2–10.4 × 6.5–8.5 µm) and basidia (45–80 × 6–9 µm), and 7–9 µm wide hyphal ends (pseudocystidia) ( Crous et al. 2019). C. griseoviolacea is morphologically similar to Clavulina tuxtlasana M. Villegas, Garibay-Orijel & Pérez-Pazos in the color of basidiomata, but C. tuxtlasana basidiomata are simple, rarely branching dichotomously, branches with slight longitudinal wrinkles, smaller basidiospores (6–7.5 × 5.5–7 µm), and lacking clamp connections ( Salas-Lizana et al. 2023). Clavulina crystallifera Meiras-Ottoni also has similar branching, but acerose crystals are present in the medullary hyphae of its branches ( de Meiras-Ottoni and Gibertoni 2023).

Figures

Figure 1. Phylogenetic tree generated from a ML analysis based on combined nrITS-nrLSU- rpb 2 sequences. Numbers representing Maximum Likelihood bootstrap support (MLBS ≥ 75 %, right) and significant Bayesian posterior probability (BPP ≥ 0.95, left) are indicated above the nodes. Novel sequences are printed in bold. Voucher specimens and localities where the specimens were collected are provided behind the species names.

Figure 2. Morphology of Basidiomata A – C Clavulina chengdeensis (A BJTC TX 646 holotype B BJTC ZH 1205 C BJTC ZH 1225) D – E Clavulina griseoviolacea (D BJTC ZH 0998 holotype E BJTC ZH 1653) F – I Clavulina pallida (F BJTC C 669 holotype G BJTC S 062 H BJTC ZH 1055 I BJTC C 229). Scale bars: 1 cm.

Figure 3. Morphology of Basidiomata A – C Clavulina chengdeensis (A BJTC TX 646 holotype B BJTC ZH 1205 C BJTC 0249) D Clavulina griseoviolacea (D BJTC ZH 0998 holotype) E – G Clavulina pallida (E BJTC C 669 holotype F BJTC S 062 G BJTC ZH 0056). Scale bars: 1 cm.

Figure 5. Microscopic characteristics of Clavulina griseoviolacea A basidiospores B basidia C tramal hyphae. Scale bars: 10 µm.