Dacrymyces chiangraiensis Ekanayaka, S.C. Karunarathna, Q. Zhao & K D. Hyde

Index Fungorum number: IF552549 Facesoffungi number: FoF 2696

Etymology: Name reflects the province, where the type species was collected

Holotype: MFLU 16-0572

Saprobic on wood, stems and twigs. Sexual morph Basidiomata 478–482 × 908–915 µm ( = 480.8 × 911.6 µm, n = 10) superficial, mostly solitary, sometimes gregarious, pulvinate, yellow to orange. Sterile parts of basidiocarps covered with simple or branched, tightly packed, cylindrical, septate, hyaline, thin-walled marginal hyphae. Internal hyphae branched, thin walled, gelatinous, septate, hyaline, loosely packed, clamp connections absent. Hymenium composed of dikaryophyses and basidia. Dikaryophyses 2–5.5 µm ( = 4 µm, n = 20) branched, septate, thick-walled, hyaline. Hymenium hyaline, limited to the upper surface of the basidiocarp. Probasidia 32–53 × 7–10 µm ( = 41.4 × 8.5 µm, n = 20) hyaline, guttulate, cylindrical to clavate, thin-walled, becoming bifurcate. Basidiospore 19–23 × 6.5–8 µm ( = 20.9 × 7.3 µm, n = 20), allantoid, somewhat bent, hyaline, with many transverse septa, smooth walled. Asexual morph undetermined.

Material examined: THAILAND, Mae Fah Luang University, Chiang Rai Province, 22 December 2014, A.H. Ekanayaka, (MFLU 16-0572, holotype). GenBank number ITS:KY498587.

Notes: Dacrymyces chiangraiensis is phylogenetically close to D.san-augustinii. However, they are separated with strong bootstrap support. Morphologically D. chiangraiensis is similar to D. san-augustinii in having yellow to orange pulvinate basidiomata, but they differ in the size of the basidiomata and colour of probasidia and basidiospores. Dacrymyces san-augustinii has larger basidiomata (1–2 mm high, 1–3 mm diam.) with pale yellow probasidia, and subhyaline, smaller basidiospores (15.5–23.6 × 4.6–6.8 µm) (McNabb 1973). Dacrymyces chiangraiensis differs from D. novae-zelandiae in having yellow to orange non-gelatinized basidiomata with smaller probasidia (Ellis and Ellis 1990; Shirouzu et al. 2009).

The best scoring RAxML maximum likelihood phylogenetic tree based on a combined ITS and SSU sequence dataset. Strain/culture numbers are given following the taxon names. The newly generated sequences are in blue. Bootstrap support values for maximum likelihood >60% are given near the nodes. The tree is rooted with Exidia uvapsassa (AFTOL ID 461).


Morphology of Dacrymyces chiangraiensis (MFLU 16-0572, holotype). a Substrate. b Basidiomata on wood. c Cross section of basidiome. d Close up of the hymenium layer and interscal tissue. e Close up of hymenium layer. f Septate, branched hyphae. g, h Probasidia. i, j Developing basidia. k, l Ellipsoid basidiospores. Scale bars: a = 1000 µm, b = 200 µm, = 200 µm, c = 400 µm, d = 100 µm, e = 100 µm, f = 15 µm, g-j = 20 µm, k, l = 5 µm.