Four new corticioid species in Trechisporales (Basidiomycota) from East Asia and notes on phylogeny of the order Author Liu, Shi-Liang Author Ma, Hai-Xia Author He, Shuang-Hui Author Dai, Yu-Cheng text MycoKeys 2019 48 97 113 http://dx.doi.org/10.3897/mycokeys.48.31956 journal article http://dx.doi.org/10.3897/mycokeys.48.31956 1314-4049--97 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 x 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 x 5-6 µm . Basidia suburniform to subclavate, hyaline, thin-walled , with 4 sterigmata and a basal clamp connection, 20-30 x 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) x (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 x 3-4 µm for D. capitata in Gilbertson and Blackwell 1988 ; 12-19 x 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). Figure 3. Dextrinocystis calamicola (holotype, He 5701). a basidiomata b, f basidiospores c, g basidia d, h cystidia e, i cystidia-like branches in subiculum j subicular hyphae. Scale bars: 1 cm (a), 10 µm ( b-j ). b, c Taken in phloxine d, e taken in Melzer's reagent.