Postia cylindrica H.S. Yuan, 2017

Yuan, Hai-Sheng, Mu, Yan-Hong & Qin, Wen-Min, 2017, A new species of Postia (Basidiomycota) based on morphological and molecular characteristics, Phytotaxa 292 (3), pp. 287-295 : 290-291

Postia cylindrica H.S. Yuan , sp. nov. ( Figs. 2 , 3 )

MycoBank no.: MB 817085

Differs from Postia leucomallella in having cylindrical basidiospores and absence of gloeocystidia.

Holotype: CHINA. Jiangxi Prov., Jiujiang County, Lushan Mt. , on dead tree of Pinus , 2.VIII.2015 Yuan 8340 (holotype in IFP).

Etymology: the species epithet cylindrica referring to the cylindrical basidiospores.

Fruiting body:—Annual, resupinate to effused reflexed, soft and fleshy, without odour or taste when fresh, becoming soft corky and brittle when dry. Resupinate part 6 cm long, 4 cm wide and 3 mm thick, tightly adnate, sterile margin thinning out, cream to pale buff; pileus projecting up to 5 mm long, 4 cm wide, and 4 mm thick at the base. Pileal surface cream to buff when fresh, buff to cinnamon-buff upon drying, velutinate to glabrous, azonate; margin acute, reddish-brown and incurved when dry. Pore surface white to cream-colored when fresh, unchanging color when bruised, becoming cream to buff on drying; pores round to angular, 3–4 per mm; dissepiments thin, entire to lacerate. Context white and soft, azonate, up to 1 mm thick; tubes cream and soft corky, up to 3 mm long.

Hyphal structure:—Monomitic; all septa with clamp connections; generative hyphae IKI–, CB–; hyphal wall distinctly swollen in KOH, then with a narrow lumen.

Context:—Generative hyphae hyaline, slightly thick- to thick-walled with a wide lumen, occasionally branched, more or less regularly arranged to loosely interwoven, 2.8–4.5 μm in diam. Cuticular layer of pileal surface consists of gloeoplerous hyphal cells, resembling gloeocystidia, thin- to slightly thick-walled, tubular to sinuous, up to 10 μm in diam.

Tubes:—Generative hyphae slightly thick- to thick-walled, occasionally branched, subparallel along the tubes, 2.3–4.5 μm in diam. Cystidia and cystidioles absent. Basidia clavate, thin-walled, with a basal clamp connection and four sterigmata, 13–16 × 4–5 μm. Basidioles in shape similar to basidia, but slightly shorter.

Basidiospores:—Basidiospores cylindrical, hyaline, thin-walled, smooth, IKI–, CB–, (4.6–)4.7–5.2(–5.4) × 1.3–1.5(– 1.6) μm, L = 4. 9 μm, W = 1.4 μm, Q = 3.46–3.49 (n=60/2).

Additional specimen examined: China. Jiangxi Prov., Jiujiang County, Lushan Mt., on dead tree of Pinus , 2.VIII.2015 Yuan 8317 (IFP).

Other specimen examined: Postia leucomallella : Finland. EH. Lammi Biological Station, on fallen trunk of Pinus , 8.X.1992 Dai 227 (IFP).

Figures

FIGURE 2. Basidiocarps of Postia cylindrica (holotype).

FIGURE 3. Microscopic structures of Postia cylindrica. a: Basidiospores. b: Basidia and basidioles. c: Hyphae from trama. d: Hyphae from subiculum. e: Gloeoplerous hyphal ends of cuticular layer.