Multilocularia bambusae Phookamsak, Ariyawansa & K.D. Hyde, sp. nov.
Index Fungorum number: IF 551947, Facesoffungi number: FoF 01659, Fig. 1
Etymology: The specific epithet “bambusae” refers to the host
Holotype: MFLU11–0216

Saprobic on bamboo. Sexual morph Ascostromata 200 – 240 μm high, 1100 – 1900 μm long, gregarious, clustered, immersed, raised, in black rows on host surface, multi-loculate, elongate, glabrous, ostiolate. Locules 130 – 240 μm high, 200 – 700μm diam., clustered, immersed in ascostromata, globose to subglobose, or elongate hemisphaerical, ostiole individually central. Peridium 10 – 40 μm wide, thin – to thick-walled slightly thick at the rim, composed of several layers of small, brown to dark brown pseudoparenchymatous cells, arranged in a textura prismatica to textura angularis, and arranged in textura porrecta at the sides among the locules. Hamathecium composed of dense , 1.2 – 2 μm wide , cellular pseudoparaphyses, distinctly septate, anastomosing among the asci, embedded in a hyaline gelatinous matrix. Asci (64–)70 – 90(–94) × (10–)11 – 14(–17) μm (x̄ = 82.5 × 14.2 μm, n = 30), 8-spored, bitunicate, fissitunicate, clavate, long pedicellate (30 – 50 × 3 – 5 μm), apically rounded, with welldeveloped ocular chamber. Ascospores (11–) 12 – 15 (–16) × (3–) 4 – 5 (–7) μm (x̄ = 14.2 × 4.7 μm, n = 30), overlapping 1 – 2 – seriate, hyaline, ellipsoidal, with rounded ends, slighty curved, 3 – septate, rarely 1 – to 4 – septate, slightly constricted at the central septum, smooth-walled, with small guttules. Asexual morph Undetermined.

Culture characteristics: Colonies on PDA reaching 30 – 40 mm diam. after 4 weeks at 25 – 30 °C, colony from above, dark greenish to black at the margin, white to orange in the middle, white at the centre; from below, dark greenish to black; medium dense, irregular, slightly raised to umbonate, surface slightly rough, dull with umbonate edge, concave at the centre, fluffy to floccose, with white tufts at the centre; producing brown pigmentation in agar.

Material examined: THAILAND: Chiang Rai Province, Mae Jun District, Huai kang Pla Waterfall, on dead stem of bamboo (Poaceae), 25 October 2010, R. Phookamsak, RP0096 (MFLU 11–0216, holotype), ex-type living culture, MFLUCC 11-0180, BCC.

Fig. 1 Multilocularia bambusae (holotype) a Appearance of ascostromata on host surface b Section through an ascostroma c Appearance of locules d Section through peridium e Asci with pseudoparaphyses, stained in congo red f, g Asci h – l Ascospores m Ascospore stained congo red n Spore germination on WA after 8 h. Scale bars: b = 200 μm, c = 100 μm, d = 50 μm, e – g = 20 μm, n = 10 μm, h – m = 5 μm.