Dextrinocystis calamicola S.H. He & S.L. Liu

Liu, Shi-Liang, Ma, Hai-Xia, He, Shuang-Hui & Dai, Yu-Cheng, 2019, Four new corticioid species in Trechisporales (Basidiomycota) from East Asia and notes on phylogeny of the order, MycoKeys 48, pp. 97-113 : 101-103

Dextrinocystis calamicola S.H. He & S.L. Liu sp. nov. Fig. 3

Typification.

CHINA. Fujian Province, Wuyishan County, Wuyishan Nature Reserve, on dead culms of Calamus , 3 Oct 2018, He 5701 (holotype, BJFC 026763).

Etymology.

“calamicola” refers to growing on Calamus .

Basidiomata.

Annual, resupinate, effused, thin, soft, easily separated from the substrate, at first as irregular small patches, later confluent up to 15 cm long, 2 cm wide. Hymenophore surface smooth, orange white (5A2) to greyish-orange [5B(3-5)], finely cracked with age; margin thinning out, fimbriate, slightly paler than hymenophore surface, becoming indistinct with age.

Microscopic structures.

Hyphal system monomitic; generative hyphae with clamp connections, hyaline, thin-walled, frequently branched and septate, loosely interwoven, 2-3 µm in diam. Cystidia-like branches present, branched from subicular hyphae, embedded, hyaline, thick-walled, encrusted at apex, 20-30 × 1.5-2 µm. Hymenial cystidia abundant, subulate, projecting beyond hymenium, bi- or multi-rooted, hyaline, distinctly thick-walled with a narrow lumen, slightly encrusted at apex, distinctly dextrinoid, 50-110 × 5-6 µm. Basidia suburniform to subclavate, hyaline, thin-walled, with 4 sterigmata and a basal clamp connection, 20-30 × 5-8 µm; sterigmata mostly cylindrical with a blunt tip; basidioles in shape similar to basidia, but slightly smaller. Basidiospores abundant, oblong ellipsoid to short cylindrical, hyaline, thin-walled, smooth, negative in Melzer’s reagent, acyanophilous, (7 –)7.5–8.8(– 9) × (3.2 –)3.3– 4 µm, L = 8.1 µm, W = 3.7 µm, Q = 2.1-2.2 (n = 60/2).

Additional specimens examined.

CHINA. Fujian Province, Wuyishan County, Wuyishan Nature Reserve, on dead culms of Calamus , 3 Oct 2018, He 5693 (BJFC 026755) & He 5700 (BJFC 026762).

Remarks.

The thin whitish basidiomata on a palm tree, distinctly thick-walled cystidia with a dextrinoid reaction in Melzer’s reagent, presence of small cystidia-like branches and short cylindrical basidiospores indicate that the new species is a member of Dextrinocystis . Two species, D. capitata (D.P. Rogers & Boquiren) Gilb. & M. Blackw. and D. macrospora (Liberta) Nakasone have been reported in the genus, both of which differ from D. calamicola by having much larger basidiospores (11-14 × 3-4 µm for D. capitata in Gilbertson and Blackwell 1988; 12-19 × 4.5-7 µm for D. macrospora in Liberta 1960) and a distribution in America. In the phylogenetic tree, D. calamicola formed a sister lineage to Tubulicium with relatively strong support (Fig. 2).