Hypospilina bifrons  

Description contributed by Graham Kinsey (CABI).

Anamorph: unknown.

Teleomorph: stromata 0.3-1 mm broad, ± angular, discoid, equal in thickness to the host leaf, with sharply delimited margins, outer layer blackened, visible on both sides of the leaf, interior paler, containing 1-10 ascomata. Ascomata perithecia, 100-300 µm diam, depressed globose to lenticular, the neck eccentric, curving to emerge perpendicular to the host surface, inconspicuous and scarcely emergent. Peridium 5-7 µm thick, pale brown, composed of 2-3 layers of flattened cells, irregularly lobed in surface view. Interascal tissue not seen. Asci 45-53 x 8-12 µm, clavate to cylindrical-clavate, with a tapering base, apex somewhat truncate, thick-walled particularly near the apex, with a refractive apical ring, 8-spored, J-, becoming detached within the perithecial cavity but often remaining stuck together. Ascospores 10-14 x 3.5-5 µm, narrowly ellipsoidal or somewhat ovoid, slightly curved, hyaline, 1-septate, the septum dividing the length ca 5:1, sometimes with faint appendages.