Pseudoastrosphaeriella longicolla

Pseudoastrosphaeriella longicolla Phook. & K.D. Hyde

Index Fungorum number: IF551645; Facesoffungi number: FoF 01237

Holotype: MFLU 11-0207

Etymology: The epithet “longicolla” refers to ascostromata with long neck.

Saprobic on bamboo, visible as numerous, black domes, with spike-like structures on host surface, covered by dense, brown vegetative hyphae. Sexual morph: Ascomata 350–570μm high (excluding neck), 900–1200μm diam., scattered, gregarious, immersed in host epidermis, becoming raised, erumpent through host tissue by papilla, depressed conical or lageniform, flattened at the base, uniloculate, glabrous, coriaceous, ostiolate. Necks 1.4–2.5 mm high, 110–175μm diam., black, central, cylindrical, oblique, internally periphysate, brittle, carbonaceous. Peridium 10–60μm wide, of unequal thickness, thick at the sides towards the apex, composed of small, dark brown to black, pseudoparenchymatous cells, outer layers comprising host cells plus fungal tissue, arranged vertically in a textura angularis, poorly developed at the base, with palisade-like cells at rim. Hamathecium composed of dense, filiform, 0.7–2 μm wide, trabeculate pseudoparaphyses, anastomosing at the apex, embedded in a hyaline gelatinous matrix. Asci (140–)160–180(–200)(–240) × (10–)12–15(–17) μm (x̄ = 179.3 × 13.7 μm, n = 30), 8-spored, bitunicate, cylindric-clavate, with a furcate pedicel, apically rounded with well-developed ocular chamber. Ascospores (48–)50–60(–63.5) × 5.5–7(–7.5) μm (x̄ = 55 × 6.3 μm, n = 30), overlapping uni- to bi-seriate, pale yellowish when young, becoming reddish brown to dark brown at maturity, fusiform, with acute ends, 1-septate, constricted at the septum, slightly swollen above central septum, rough-wall, with longitudinal ridges. Asexual morph: Undetermined. (Description from Phookamsak et al. 2015)

Material examined: THAILAND, Chiang Mai Province, Chom Tong District, Doi Inthanon, on dead branch of submerged bamboo, 16 November 2010, R. Phookamsak, RP0087 (MFLU 11-0207, holotype), ex-type living culture, MFLUCC 11-0171.

Notes: Pseudoastrosphaeriella longicolla is similar P. papillata by having coriaceous ascostromata with long necks and was found on submerged bamboo. However, P. longicolla differs from P. papillata due to its ascospores. Pseudoastrosphaeriella longicolla has larger ascospores, with reddish brown, narrowly fusiform and distinct longitudinal ridges. Whereas P. papillata has smaller, broadly fusiform to clavate, rough-walled ascospores, with small appendages at both ends. Hu (2010) described a species Astrosphaeriella francensis in her study, but it was not validly published. Pseudoastrosphaeriella longicolla is also similar to this species in having coriaceous ascostromata, with long necks and narrow fusiform, striate ascospores. However, Pseudoastrosphaeriella differs from Astrosphaeriella francensis due to its ascospore septation which are often only 1-septate in P. longicolla. Whereas A. francensis having ascospores with 1–3(–5) septa. Based on phylogenetic analyses, Pseudoastrosphaeriella longicolla forms a distinct clade at the base of Pseudoastrosphaeriellaceae, close to P. africana. (Notes from Phookamsak et al. 2015)

Freshwater distribution: Thailand (Phookamsak et al. 2015)