Aggregated cluster of ascomata; asci with brown, muriformly septate ascospores.

Cucurbitaria berberidis on stems of Berberis julianae. Photo Credit: H.A. van der Aa & C.N. Swart-Velthuyzen, specimen CBS H-11629, culture CBS 394.84

The genus Cucurbitaria (Cucurbitariaceae, Dothideomycetes) is based on C. berberidis, which has Pyrenochaeta berberidis as asexual morph (de Gruyter et al. 2013). Currently, 450 species are accepted in Cucurbitaria (http://www.mycobank.org/mycotaxo.aspx). Members of Cucurbitaria usually grow saprobically on dead twigs and branches.

Asomata black, globose, aggregated in clusters, erumpent through cracks in the bark, strongly verrucose, at times covered with short, dark brown, thick-walled, blunt setae; outer wall region of dark brown, thick-walled textura angularis; inner wall region of pale brown, thin-walled textura angularis. Pseudoparaphyses cellular, septate, intermingled among asci. Asci cylindrical, short-stalked, thick-walled, fissitunicate, the apex rounded with a distinct inner layer, 8-spored. Ascospores variable in shape, subcylindrical with acute to obtuse ends, muriformly septate, golden brown. Conidiomata uniloculate, similar in structure but smaller than the ascostromata; black, smooth or slightly verrucose, frequent covered with short, dark, thick-walled, blunt setae. Conidiophores lining the inner cavity, hyaline smooth, cylindrical, with each cell producing a single conidiogenous cell. Conidiogenous cells ampulliform to slightly tapered, thin-walled, phialidic, with conidiogenous loci formed laterally just below each septum. Conidia cylindrical to bacilliform, straight, thin-walled, hyaline, aseptate.

References:

• Gruyter J de, Woudenberg JHC, Aveskamp MM, Verkley GJM, Groenewald JZ, Crous PW. (2013). Redisposition of Phoma-like anamorphs in Pleosporales. Studies in Mycology 75: 1–36.