Astrocystis cocoes (Henn.) Laessøe & Spooner, Kew Bull. 49(1): 27 (1994) (Fig. 6)

≡ Rosellinia cocoes Henn., Hedwigia 47(4): 256 (1908)

MycoBank: MB580660

Saprobic on the surface of dead bamboo stalk, visible as black raised spots on the host. Sexual morph: Stromata erumpent, solitary or gregarious, not or somewhat confluent, black, carbonaceous, containing 1 ascoma, almost conical with a round apex, 0.4–0.6 mm diam., 0.5–0.8 mm high, with an outer stellate layer; persistent pale squamules from host cuticle, apex smooth and sometimes almost annulate with a minutely papillate ostiole. Asci 118–129 × 6.6–8.5 μm (mean 123 × 7.6 μm, n = 30), 8-spored, spore bearing part cylindrical, stipe short and tapering, apically rounded, with a discoid, subapical, J+ apical apparatus, with sides tapering to the base, blue staining in Melzer’s reagent, 2.4–3.5 μm (mean 2.8 μm, n = 30) high, 2.0–3.2 μm (mean 2.8 μm, n = 30) wide. Ascospores 18.1–22.8 × 5.5–6.0 μm (mean 19.8 × 6.2 μm, n = 30), overlapping uniseriate, aseptate, dark reddish brown, inequilaterally fusiform, with one or both ends beaked, flattened side slightly convex, with a germ slit on flattened side, less than full spore-length, with thin mucilaginous sheath and pad-like polar appendages. Asexual morph: undetermined.

Specimens examined:— CHINA. Hainan Province: Wuzhishan City, Wuzhishan Nature Reserve (18.541959°N, 109.405444°E), elev. 767 m, on dead bamboo culms, 11 October 2020, Q.R. Li 2020WZS64-3 (GMB0037; KUN-HKAS 112701; living culture, GMBC0037) .

Culture characteristics:— Ascospores germinated on PDA within 24 hours at 25 °C, colonies, dense but thinning towards the edge, edge irregular, white from above, reverse similar in colour. No conidia were observed on PDA or OA media.

Habitat/Distribution:— Known to inhabit dead bamboo, Brazil, China, India, Philippines.

Notes:— Astrocystis cocoes was described on dead branches of Cocos nucifera (Laessøe & Spooner 1994) collected from Philippines. Our new collection (GMB0037) morphologically resembles A. cocoes . Astrocystis cocoes is distinct from A. sublimbata by its size of ascospores (15–19 × 6.5–8.5 μm vs 17–22 × 7.5–9.5 μm). Moreover, the ascospores of A. sublimbata do not possess a mucilaginous sheath and pad-like polar appendages (Smith & Hyde 2001). Phylogenetic analyses of the combined ITS, RPB2, β-tubulin and α-actin genes show that GMBC0037 groups with A. cocoes with high support (100% ML, 1.00 BYPP; Fig. 1). This is the first report of A. cocoes from China.