Diademaceae Shoemaker & C.E. Babc., Can. J. Bot. 70(8): 1618 (1992).
MycoBank number: MB 81955; Index Fungorum number: IF 81955; Facesoffungi number: FoF 08207, 8 species.
Parasitic or saprobic on decaying stems and leaves. Colonies dark brown to black with subepidermal or subcuticular and later become superficial. Sexual morph: Ascomata subepidermal or subcuticular and later become superficial, dark brown to black, globose, opening via a flat, circular lid. Peridium consisting of small, pigmented, thick-walled cells of textura angularis. Hamathecium comprising dense, cellular pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, clavate or ellipsoidal, with short, broad, furcate pedicel, apically rounded with an ocular chamber. Ascospores 2-seriate, fusiform, brown, with 3 or more transverse septa, with or without longitudinal septa, applanate or rarely terete, with a thick sheath most of the time. Asexual morph: Undetermined.
Type – Diadema Shoemaker & C.E. Babc.
Notes – Diademaceae was introduced by Shoemaker & Babcock (1992) based on the ascomata characteristic of opening by a flat, circular lid, and comprised five genera (Clathrospora, Comoclathris, Diadema, Diademosa and Macrospora) (Shoemaker & Babcock 1992). Later Clathrospora, Comoclathris, Diademosa and Macrospora were transferred to Pleosporaceae (Kruys et al. 2006, Lumbsch & Huhndorf 2010, Ariyawansa et al. 2014a). Wijayawardene et al. (2018) accepted two genera Diadema and Diademosa in this family. We agree with Ariyawansa et al. (2014a) to transfer Diademosa to Pleosporaceae. This genus needs recollecting to confirm its placement with DNA sequence data. In this study, we accept only Diadema in Diademaceae.