Phaeoclavulina aeruginea P. Zhang, 2022

Liu, Wen-Hao, Yan, Jun, Deng, Peng-Tao, Qin, Wei-Qiang & Zhang, Ping, 2022, Two new species of Phaeoclavulina (Gomphaceae, Gomphales) from Hunan Province, China, Phytotaxa 561 (1), pp. 27-40 : 31

Phaeoclavulina aeruginea P. Zhang , sp. nov. ( Figs. 1 , 2 , 4 )

Mycobank no.: 845329

Diagnosis: —Basidiomata coralloid, stipe single, cylindrical at the base, and gradually thinning upward to produce branches, with brown base and distinctive copper-green tips, and the context is yellowish-white, turning wine red when injured. Basidiospores are large, echinulate, and cyanophilic. Basidia with 2 sterigmata, clamp connection is always present in all tissues.

Holotype: — CHINA. Hunan Province: Chenzhou, Yizhang County, Mangshan National Forest Park , 1205 m, 24°57′13.58″ N, 112°56′14.21″ E, 12 September 2016, P. Zhang MHHNU8909 (holotype, MHHNU!); KUN-HKAS 124382 (KUN-HKAS).

Etymology:—Aeruginea (Lat.): refers to the distinctive copper-green color of the tips of the basidiomata branches.

Basidiomata ( Fig. 1a, b ):—Coralloid, 3–6 cm tall × 4–7 cm wide. Stipe 2–3 cm tall × 1–2 cm wide, snow-white rhizomorphic strands near the ground, which gradually turn yellowish white; many branches diverge from the stalk, then branch dichotomously approximately 4–5 times; stipe surface pale brown when young and dark brown [6E3-6, Cameo Brown, Rood’s Brown, Cacao Brown, or Walnut Brown] when old, the inner flesh is yellowish white, all parts turn wine red when injured. The top of the branch is blunt and short, and has a distinctive copper-green color [26D4-6, Light Porcelain Green, Light Terre Verte, Terre Verte, Niagara Green].

Basidiospores ( Fig. 2a , Fig. 4a ) [60/3/2] (10–)13–16(–20) × (6–)8–9(–10) µm [Q = 1.70–2.14(–2.37), Q = 1.81 ± 0.19], elongate-ellipsoid, pale yellow to golden yellow in mass, thick-walled, acute echinulate, broad spines 3–4 µm high, cyanophilic, with oil droplet contents. Hilar appendix acuminate (3 µm in length). Basidia ( Fig. 2b ) 50–65 × 10–12 µm, clavate, 2 sterigmata, basically 3 µm width, 5 µm length, clamped. Hyphae ( Fig. 2c, d ) parallel, up to 5 µm wide, inflated, hyaline, thin-walled, clamp connections present. Odor and taste not recorded.

Habit and distribution: —Solitary or gregarious, humicolous, in a mixed forest at approximately 1200 m elevation.

Additional specimens examined: — CHINA. Hunan Province: Chenzhou, Yizhang County, Linhai Villa , 1250 m, 24°57′47″ N, 112°57′31″ E, 15 September 2003, P. Zhang MHHNU6887 ( MHHNU!) CHINA. Hunan Province: Chenzhou, Yizhang County, Mangshan National Forest Park , 1205 m, 24°57′13.58″ N, 112°56′14.21″ E, 12 September 2016, P. Zhang MHHNU8901 ( MHHNU!) .

Comments:— Phaeoclavulina aeruginea is distinguished from other species by the unique copper-green color of the branch tips. This blue tone is characteristic and is a taxonomic character that has evolved in several species. In the wild, it is easy to confuse with Phaeoclavulina cyanocephala (Berkeley & Curtis 1868: 191) ( Giachini 2011: 191) , but P. cyanocephala has larger basidiomata (8–18 × 2–7 cm), the surface is yellowish brown or ochre brown, and the upper branch and branch tips are purple gray, whereas the basidiomata of P. aeruginea are 3–6 × 4–7 cm, the stipe and branches are brown, the top of the branch is copper green, and the inner flesh is yellowish white, becoming wine red when bruised. The spores of Phaeoclavulina aeruginea are large (13–16(–20) × 8–9(–10) µm) and clearly seen under a scanning electron microscope, the surface is ornamented with long spines (3–4 µm), and the hilar appendix is acuminate.The spores of P. cyanocephala are teardrop shaped or broadly comma-shaped. Phaeoclavulina cyanocephala is distributed worldwide and mainly in Yunnan Province in China. It was found on the ground of a broad-leaved forest or a bamboo forest in low-altitude tropical areas in summer. The new species is only known from a coniferous forest in Hunan Province. The abovementioned morphological characters and molecular phylogenetic analyses show that P. aeruginea is a distinctive novel species.

Figures

FIGURE 1. Basidiomata of Phaeoclavulina aeruginea (a. MHHNU8909), Bars a = 2 cm; Branch tips of Phaeoclavulina aeruginea (b. MHHNU8909), Bars b = 0.25 cm. Basidiomata of Phaeoclavulina cinnamomea (c. MHHNU10376), Bars c = 2 cm; Branch tips of Phaeoclavulina cinnamomea (d. MHHNU10376), Bars d = 0.25 cm.

FIGURE 2. Microscopic features of Phaeoclavulina aeruginea (MHHNU8909, holotype). a Basidiospores; b Basidia; c Hyphae from context; d Hyphae from trama. Bars: a, c, d = 10 μm, b = 20 μm.

FIGURE 4. Basidiospores of a Phaeoclavulina aeruginea (MHHNU8909) and b Phaeoclavulina cinnamomea (MHHNU10376).