Anamorph. Cephalosporiopsis sp.
Mycelium not evident, or appearing as a ring of white hyphae around each perithecial base. Perithecia superficial, nonstromatic, globose to pyriform with a flat apex, white, 150-250 µm diam., with an ostiolar disc of intertwined hyphae. Asci clavate, (50-)60-80(-87) x (6-)8-11 µm, apex with an obscure ring, often appearing simple. Ascospores clavate to fusiform, 27-42 x 3-4.5 µm, 5-9(-13)-septate, smooth, colorless.

Habitat. On woody and herbaceous debris.

Notes. For illustrations and complete descriptions see Samuels (1978, as Nectria corynospora) and Rossman (1983, as Nectria opalina). Rossman (1983) gave Nectria corynospora as a synonym of N. opalina. However, perithecia of N. opalina were originally described as being half immersed in the substrate, and with a papilla (Crouan & Crouan, 1867). Ms. Rosalind Lowen (NY) has reexamined the type collection of N. opalina (CO), finding an immersed ascomycete with light-colored perithecia and phragmosporous ascospores; the ascal apex was thickened, however, typical of the Clavicipitales. Because perithecia of Peristomialis corynospora are entirely superficial, and because its asci lack apical thickening, it is unlikely that P. corynospora and N. opalina are conspecific. Rossman's (1983) description agrees in all details with P. corynospora, thus suggesting that at least one perithecium of the species was indeed present with perithecia of the type of N. opalina.