Nodulosphaeria Rabenh., Klotzschii Herb. Viv. Mycol., Edn Nov, Ser. Sec., Cent. 8: no. 725 (in sched.) (1858).
Saprobic or hemibiotrophic mostly on herbaceous dicotyledons. Sexual morph: Ascomata scattered, solitary to gregarious, immersed to semi-immersed, or erumpent through host epidermis at maturity, visible as black dots on host surface, uniloculate, globose to subglobose, setose, covered by hyphae, dark brown to black, ostiole central, papillate, with broad setae in ostiolar canal, towards the apex. Peridium thin to thick-walled, of equal thickness, composed of two types of brown to dark brown, pseudoparenchymatous cells, arranged in a textura angularis to textura globulosa. Hamathecium composed of numerous, filamentous, anastomosing, broad cellular pseudoparaphyses, with distinct septa. Asci 8-spored, bitunicate, fissitunicate, clavate to cylindric-clavate, subsessile to short pedicellate, apically rounded with indistinct ocular chamber. Ascospores overlapping 2–4-seriate, phragmosporous, cylindrical or elongated fusiform, brown to yellowish-brown, septate, with an enlarged cell near apex, smooth-walled. Asexual morph: Unknown (Adapted from Phookamsak et al., 2014).
Type species: Nodulosphaeria hirta Rabenh.
Notes: Nodulosphaeria was introduced by Rabenhorst (1858) with N. hirta as type species. Nodulosphaeria is characterized by solitary to gregarious, immersed to semi-immersed ascomata, clavate to cylindric-clavate, subsessile to short pedicellate asci and phragmosporous, cylindrical or elongated fusiform, brown to yellowish-brown, septate ascospores. Clements and Shear (1931) treated Nodulosphaeria as a synonym of Leptosphaeria. Holm (1957) reinstated Nodulosphaeria with N. hirta as type species. Shoemaker (1976) transferred several species of Nodulosphaeria to Ophiobolus. Barr (1979) treated Nodulosphaeria in Phaeosphaeriaceae based on morphological similarities to Ophiobolus such as ascospores forming an enlarged cell(s). Later, several authors added new species to Nodulosphaeria based on morphology and phylogeny (Shoemaker, 1984; Kulkarni, 1970; Shoemaker & Babcock, 1987, 1990; Zhang et al., 2012; Ariyawansa et al., 2015; Li et al., 2015). Mapook et al. (2016) described the sexual morphs of Nodulosphaeria hirta and N. spectabilis and described two additional Nodulosphaeria species namely N. aconiti and N. scabiosae based on morphology and phylogenetic analyses of ITS, LSU, SSU, TEF and RPB2 sequence datasets. Chaiwan et al. (2019) described the sexual morph of Nodulosphaeria digitalis from Campanula trachelium in Italy. Nodulosphaeria is morphologically and phylogenetically a distinct and well-defined genus in Phaeosphaeriaceae. Molecular markers available for Nodulosphaeria are ITS, LSU, SSU, TEF and RPB2.