Collybiopsis baiyunensis X.C. Liu & L.H. Qiu

Liu, Xiao-Chun, Lin, Zhi-Jun, Liang, Ying-Shan, Cao, Li-Xiang & Qiu, Li-Hong, 2024, Collybiopsis baiyunensis sp. nov. (Omphalotaceae, Agaricales) from Baiyun Mountain, Southern China, Phytotaxa 640 (2), pp. 183-195 : 185-189

Collybiopsis baiyunensis X.C. Liu & L.H. Qiu , sp. nov. ( Figs. 2 , 3 )

MycoBank: MB 850229

Etymology:—The epithet “ baiyunensis ” refers to the location where the type specimen was collected, Baiyun Mountain, Guangzhou, Guangdong Province, China.

Holotype:— CHINA. Guangdong Province, Guangzhou City, Baiyun Mountain , 23°10′16″N 113°17′32″E, elev. 240 m, 16 August 2021, L.H. Qiu, GDGM93885 , GenBank acc. no.: OR598795 for ITS, OR598808 for nrLSU.

Diagnosis:—This species is distinguished from other Collybiopsis species by its light brown to yellowish brown pileus with reddish orange to reddish brown disc and whitish margin, a cutis pileipellis composed of subparallel, sometimes intertwined hyphae, and clavate to broadly clavate or spheropedunculate cheilocystidia.

Description:— Pileus 23–50 mm in diam, hemispherical to convex when young, becoming applanate at maturity, sometimes with a curved or raised margin; surface dry, smooth, dull; reddish orange (#A0522D) to reddish brown (#601F00) at the disc, light brown (#E9C68D) to yellowish brown (#B88951) towards the margin, usually whitish (#FFFDF8) at the margin. Lamellae adnexed, subdistant, L = 25–37, l = 1–6, white to light brown in color. Stipe 30–85 × 2.4‒4.1 mm, cylindrical, central, hollow, surface dry, yellowish brown (#B88951) to reddish brown (#601F00), sometimes light brown (#E9C68D) at upper half, reddish brown (#601F00) at lower half, base slightly thickened with white mycelium. Smell indistinctive. Taste not obtained.

Basidiospores [130/5/3] (6.2–) 6.8–9.5 (11.3) × (2.9–) 3.3–4.5 (–4.9) μm, avl × avw = 8.2 × 3.9 µm, Q = (1.84–) 1.87–2.33 (–2.40), Q m = 2.10 ± 0.14, oblong to subcylindrical, smooth, thin-walled, hyaline in 5 % KOH, non-dextrinoid. Basidia (20.2–) 20.6–27.7 (31.1) × (5.2–) 5.5–8.4 (–8.6) μm, avl × avw = 23.7 × 7.1 µm, 4-spored, hyaline, thin-walled, clavate, sometimes constricted or curved. Cheilocystidia (15.6–) 16.6–32.6 (37.7) × (8.3–) 8.8–13.6 (15.6) μm, avl × avw = 22.8 × 10.9 µm, clavate to broadly clavate, spheropedunculate, sometimes with obtuse or slightly acute apex, thin-walled, smooth. Pleurocystidia absent. Trama hyphae cylindrical, subparallel in arrangement, some part inflated, hyaline, thin-walled, smooth, non-dextrinoid, 2.3–14.2 µm in diam, avw = 4.7 µm. Pileipellis a cutis, hyphae subparallelly arranged, sometimes intertwined, 3.0–7.5 μm wide, avw = 4.8 µm, cylindrical, hyaline, thin-walled, smooth. Stipitipellis a cutis made up of cylindrical, parallel-arranged hyphae, thin-walled, smooth, 2.2–10.3 µm in diameter, avw = 5.5 µm. Caulocystidia (17.2) 21.2–71.2 (100.6) × (3.3–) 3.6–6.4 (–7.0) μm, avl × avw = 39.5 × 4.6 µm, abundant, cylindrical, flexuose, thin-walled, hyaline. Clamp connections present in all tissues.

Habitat:—Solitary or scattered in leaf litter or on living trees of an evergreen broadleaf forest.

Distribution:—Currently known from Guangdong Province, China.

Additional specimens examined:— CHINA. Guangdong Province, Guangzhou City, Baiyun Mountain , 16 August 2021, coll: X.X. Huang GDGM93884 ; 29 May 2022, coll: Z.J. Lin & Y.S. Liang GDGM93886 ; 14 September 2023, coll: X.C. Liu GDGM93887 . Guangdong Province, Zhaoqing City, Dinghushan Biosphere Reserve , 3 May 2017, coll: L.H. Qiu K17050311 ; ditto 29 June 2017, coll: L.H. Qiu H17062908, GDGM93883 .

Figures

FIGURE 2. Collybiopsis baiyunensis sp. nov.: a–g. Basidiomata (a–b: K17050311; c: GDGM93885, holotype; d–e: GDGM93884; f: GDGM93886; g: GDGM93887) Scale bar: a–g = 1 cm. Photos by L.H. Qiu and X.C. Liu.

FIGURE 3. Microscopic features of Collybiopsis baiyunensis sp. nov.: a. Basidiospores; b. Basidia; c. Cheilocystidia; d. Stipitipellis showing caulocystidia; Scale bar: a–c = 10 μm; d = 20 μm. Drawings by X.C. Liu.