Hassea bacillosa (Nyl.) Zahlbr., Beih. Botan. Centralbl. 13: 150 (1902) Fig. 1
≡ Verrucaria bacillosa Nyl., Lichens of South California, edn 2: 20 (1898)
Index Fungorum number: IF 386699; Facesoffungi number: FoF 06246
Lichenicolous on the rock. Sexual morph: Ascomata 275–295 μm high × 235–275 μm diam., perithecial, subglobose to applanate, carbonaceous, black, smooth or rough, semi-immersed or superficial in the thallus of the host, ostiolate, with a central ostiole located in a papilla; singly scattered or more rarely crowded in small groups, slightly glistening. Peridium 18–45 μm continuous, composed of three layers: an inner excipular layer and two outer involucrellum layers; extemal involucrellum layer carbonaceous, consisting of isodiametric, thick-walled cells, with enlarged lumina and black walls; intemal involucrellum layer colorless to black, paraplectenchymatous, consisting of isodiametric, thin-walled cells, with enlarged lumina and a colorless to pigmented wall; intemal involucrellum layer thicker than the extemal one; excipular layer: thinner, hyaline, composed of cells becoming laterally compressed, with thin, colorless walls and enlarged lumina. Hamathecium 0.8–1.9 μm composed of paraphyses and periphyses. Paraphyses septate, simple, poorly branched becoming evanescent, branched, hymenial gelatineous. Asci 46–69 µm × 8–10 µm (x̅ = 56.2 × 9.3 µm, n = 10), 8-spored, elongate claviform to cylindrical, shortly stalked, unitunicate, thin-walled, slightly thickened at the apex of young asci. Ascospores 29–39 µm × 2.3–2.4 µm (x̅ = 35.5 × 2.3 µm, n = 10), overlapping in the ascus, simple, cylindrical to filiform, one or more transverse septa, not constricted at the septa, thin-walled without mucilaginous sheath. Asexual morph: Undetermined.
Material examined – USA, California, foothills of the Santa Monica Range near the Soldiers Horne, on the rock, 1 January 1897, A. Zahlbruckner (FH 00213640, holotype).
Economic significance – None is reported.