Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Hyphal strands: superficial, black, aggregated in dark patches of numerous hyphal strands on the host thallus; strands: not markedly radiating, both plurihyphal (stromatic) and 1-cell wide, abundantly ramified, irregularly branched, convex; plurihyphal strands: dark brown, with 2-3 rows of cells, about 150-250 µm long and 8-12(-16) µm wide; 1-cell wide strands: medium brown, cells rounded, 5-7 µm wide, or elongate, 8-10 x 5-6 µm, frequently constricted at the septa; surface: coarsely ornamented with punctiform elements, less than 1 µm wide Ascomata: black, superficial, scattered, globose or elongate, recognizable as thickenings of the hyphal strands, 50-65 µm long and 30-40 µm wide, arising mostly towards the center of each dark patch internal structure: wall of the external cells: dark brown, with a granular pigment, paler in the internal ones; cells: 4-6 µm in diam. centrum: I+ pale red, K/I+ blue asci: subglobose, 15-21 x 12-16 µm, 8-spored ascospores: hyaline initially but soon brown, 1-septate, ellipsoid or obovate, slightly constricted at the septum, without halo, with a granular surface, the oldest coarsely ornamented and with fissures, 8-9.5 x 5-6 µm. Host: lichenicolous on the thallus of Caloplaca bolacina having a more markedly adverse effect on the host than other species of the genus, since the infected areoles lose their orange color and become gray due to the abundant hyphal strands and ascomata of the fungus World and Sonoran distribution: Baja California. Notes: Lichenostigma ampla is characterized by developing both plurihyphal and slender, 1-cell wide, abundantly branched strands of hyphae. Single celled strands are paler than plurihyphal ones, and their surface is markedly ornamented. Hyphal strands of L. elongata and L. subradians are thicker. Single celled strands of L. bolacinae resemble those of L. cosmopolites, but in the latter species the ascospores are hyaline. A specimen with thicker and ±radiating hyphae, representing a different Lichenostigma species on Caloplaca was also examined (from Baja California, herb. Hafellner 44872, GZU), but material was scarce.