Seiridium Nees, Syst. Pilze (Würzburg): 22 (1816) [1816-17]
Xylariomycetidae, Amphisphaeriales, Sporocadaceae, Seiridium
Index Fungorum number: IF 9868; 39 morphological species (Jaklitsch et al. 2016, Species Fungorum 2020); 20 species with sequence data.
Saprobic or pathogenic on plant substrates. Sexual morph: Ascomata immersed to erumpent, scattered or gregarious, perithecial, depressed, globose to pyriform, ostiolate. Ostioles black, central, slightly papillate, periphysate. Ascomatal wall dark brown, pseudoparenchymatous. Paraphyses hyaline, filiform, smooth. Asci 8-spored, unitunicate, cylindrical, thin-walled, pedicellate, with a J+ apical ring. Ascospores yellow to dark brown, cylindrical-oblong, euseptate, septa usually thicker than the wall, guttulate. Asexual morph: Coelomycetes. Conidiomata brown or black, semi-immersed to erumpent, acervuloid to pycnidioid, uni- to multi-locular, glabrous, upper wall comprising irregular splits upon dehiscing. Conidiomata wall multi-layered, outer layer brown, inner layer pale brown or hyaline. Conidiophores arising from the inner layer cells of the conidioma, hyaline, usually branched, septate, smooth, or reduced to conidiogenous cells. Conidiogenous cells integrated, distinct, hyaline, ampulliform to lageniform or subcylindrical, smooth, with percurrent proliferation at the apices. Conidia fusiform, distoseptate, septal pores present or absent, end cells hyaline, median cells brown to dark brown, smooth or striated, constricted at the septa or not, thick-walled; appendage often present at the apex, single, branched or unbranched, cellular; appendage at the basal cell centric or not, usually unbranched (adapted from Bonthond et al. 2018, Hyde et al. 2020).
Type species: Seiridium marginatum Nees, Syst. Pilze (Würzburg): 5 (1816) [1816-17]
Notes: Seiridium taxa are characterized by 6-celled conidia (Jeewon 2003, Maharachchikumbura et al. 2014) and are widely distributed as saprobes and plant pathogens (Tsopelas et al. 2007). The genus was established by Nees (1816). Blogiascospora and Lepteutypa were identified as the sexual morphs (Senanayake et al. 2015). Jaklitsch et al. (2016) epitypified Seiridium marginatum and confirmed its sexual morph as Blogiascospora marginata based on molecular data (notes from Hyde et al. 2020).
Species illustrated in this entry:
Seiridium spyridiicola G. Bonthond, M. Sand.-Den. & P.W. Crous