Chaetothyrina musarum (Speg.) Theiss., Annls mycol. 11(6): 495 (1913). Fig. 20

Chaetothyrium musarum Speg., Anal. Mus. nac. Hist. nat. B. Aires 6: 297 (1898).

MycoBank number: MB 239828; Index Fungorum number: IF 239828; Facesoffungi number: FoF 02009.

Epiphytic on the surface of fruit of Musa sp. Sexual morph: Thyriothecia 114–160 × 106–154 μm (= 132 × 125 μm, n = 5), superficial, solitary, circular, brown to dark brown, rounded at the margin, easily removed from host surface, poorly developed at the base, with setae, ostiole central, lacking superficial mycelium. Setae 93−118 μm long, arising from the surface of thyriothecia, straight, rounded at the apex, unbranched, septate, darkened at the septa, brown to dark brown. Upper wall 2−3 layers of cells of textura epidermoidea, brown to dark brown. Hamathecium comprising septate, pseudoparaphyses. Asci 25–40 × 12–16 μm (= 35 × 14 μm, n = 8), 8-spored, bitunicate, broadly obovoid to pyriform, rounded at apex, with an ocular chamber. Ascospores 10– 14 × 3–5 μm (= 13 × 4 μm, n = 20), 2–3-seriate, broadly ellipsoidal to fusoid, hyaline, 1-septate, slightly constricted at the septum, upper cell mostly larger than lower cell, rounded ends, smooth- walled.

Material examined – Mexico, Intercepted Laredo Texas, on fruit of Musa sp., 6 December 1959, Lopez A. (BPI 646468).

Figure 20 Chaetothyrina musarum (BPI 646468). a, b Herbarium specimens. c Thyriothecium on host surface. d Thyriothecia when viewed in squash mount. e Section through thyriothecium. f Seta arising from the surface of thyriothecium. g Upper wall of thyriothecium when viewed in squash mount. h, i Asci. j, k Ascospores. Scale bars: d = 100 μm, e, f = 50 μm, g–i = 10 μm, j, k = 5 μm.