Dothidea Fr., Observ. mycol. (Havniae) 2: 347 (1818).

Synonyms

Phragmodothis Theiss. & Syd., Annls mycol. 12(2): 179 (1914)

Systremma Theiss. & Syd., Annls mycol. 13(3/4): 330 (1915)

Saprobic on dead wood, stems and twigs. Sexual state: Ascostromata dark brown to black, erumpent through the outer layer of the host tissue, to superficial, solitary or scattered, pulvinate, globose to subglobose, coriaceous, multiloculate, with 3−15 locules, cells of ascostromata composed of several layers of dark brown cells of textura angularis. Locules globose to subglobose, broadly or narrowly conical, thick-walled, with or without ostioles. Peridium of locules comprising 1−2 layers of thick-walled, lightly pigmented, dark brown to black cells of textura angularis. Hamathecium lacking pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, clavate to sub-cylindrical, with a short broad pedicel, thickened and rounded at apex, with a clear ocular chamber. Ascospores uniseriate to biseriate, partially overlapping, hyaline, sometimes brown, 1-septate, constricted at the septum, ellipsoidal or oblong to obovoid with broadly rounded ends, smooth-walled, thick-walled, with or without a sheath. Asexual state: See notes.

Notes: Dothidea was introduced by Fries (1818) and later Fuckel (1869) assigned Dothidea as the type genus of Dothideaceae with D. gibberulosa (Ach.) Fr. as the type species. Theissen and Sydow (1915) introduced Systremma to accommodate Dothidea typified by D. sambuci Pers., while D. ribesia and D. berberidis were transferred to Dothidella (Shear 1936) which was in the subfamily Dothideae. Theissen and Sydow (1915) chose the oldest species, Sphaeria natans Tode, as the basionym and cited the later Dothidea sambuci as a synonym (Shoemaker and Hambleton 2005). Clements and Shear (1931) changed the type genus and assigned D. sambuci as the type species, in accordance with the recommendation of the Cambridge revision of the International Code (Blain 1927; Orton 1924; Shear 1936). Shoemaker et al. (2003) proposed that the type for Dothidea be formally conserved as Sphaeria sambuci Pers. (Dothidea sambuci (Pers.) Fr.:Fr.) and an epitype specimen was established by Shoemaker and Hambleton (2005). D. sambuci, D. hippophaës and D. insculpta Wallr., form a highly supported monophyletic group, and cluster with high support with other genera classified in Dothideaceae and Dothioraceae in one of the three lineages of dothideomycetous taxa (Hambleton et al. 2003; Lutzoni et al. 2004; Shoemaker and Hambleton 2005). Dothidea presently comprises 499 epithets in Index Fungorum (2014).

In our phylogenetic tree, the the epitype of Dothidea sambuci (Pers.) Fr. clustered in the the Dothideaceae clade with 99/100 % bootstrap support along with D. insculpta and we refer this clade as Dothidea sensu stricto. D. muelleri, D. hippophaës and D. berberidis are not Dothidea species in Dothidea sensu stricto and may later require a new genus.

Type species: Dothidea sambuci (Pers.) Fr., Syst. mycol. (Lundae) 2(2): 551 (1823).