Uleothyrium Petr., Annls mycol. 27(5/6): 388 (1929)

Synonym
Lembosiopeltis Bat. & J.L. Bezerra, in Batista et al., Atas Inst. Micol. Univ. Pernambuco 5: 227, 230 (1967)

Epiphytes on leaves. Superficial hyphae composed of densely branched, septate, brown hypha, lacking appressoria. Sexual state: Thyriothecia gregarious, usually clustered, circular, elongate to ellipsoidal, black or brown, surrounded by brown to black hyphae, opening by a central pore. Upper wall comprising a thin layer of mostly neatly arranged brown cells, which are branched at the outer rim, from which hyphae strands develop, base poorly developed. Asci 8-spored, bitunicate, clavate to ellipsoidal, apedicellate, apical region of asci usually with a thick opaque region. Ascospores parallel in the asci, straight or slightly curved, elongate fusoid, hyaline, 1 septate. Asexual state: “Septothyrella”, coelomycetous, Pycnidia dimidiate to scutate, densely aggretated, rounded, crusty, with wide pore. Conidiogenous cells cylindrical, flaskshaped, hyaline with brown walls, one-celled, holoblastic. Conidia hyaline, cylindrical to clavate, 1–3-septate (asexual state description from Sivanesan 1984).

Notes: Uleothyrium was formally established by Petrak (1929) as a monotypic genus represented by U. amazonicum Petr. until Sydow (1932) added U. clavisporum (Rehm) Syd. and U. leptocarpum Syd. Von Arx and Müller (1975) placed this genus in Asterinaceae based on its thyriothecium wall being composed of cells of textura radiata, 1- to 3-septate ascospores and having a pycnidial conidial state. Sivanesan (1984) also regarded this genus in asterinaceous based on the longitudinal slits in thyriothecia at maturity. The ascospores are, however, distinct, being cylindrical, hyaline, and parallel in the asci. Other genera with cylindrical, ascospores in Asterinaceae are Parasterinopsis and Schenckiella. The former differs from Uleothyrium in having a wide thyriothecial opening, while Schenckiella has brown ascospores; thus they are not congeneric.

Type species: Uleothyrium amazonicum Petr., Annls mycol. 27(5/6): 388 (1929)