TYPE. UNITED STATES. Puerto Rico, Rio Grande, on rocks in open places, 7.XII.1915, B. Fink 690 (MICH, NY, isosyntypes); Mayaguez, on rocks in open field by sea, 23.XII.1915, B. Fink 1257 (F, MICH, MIN, NY, O, US, isosyntypes); Aibonito, on rocks in open field at 2200 ft, 5.I.1916, B. Fink 1950 (NY, isosyntype).
Description.Life form: lichenized fungus.
[Translated and interpreted from the protologue (Zahlbruckner 1930)] Thallus epilithic, expanded, thin, uniform, brownish-black, opaque, minutely areolate when dry; more continuous and gelatinous when wet; edge not well delimited. Vegetative diaspores absent. Photobiont Gleocapsa cyanobacterium in purplish sheath, K+ violet. Ascomata apothecoid ascopycnocarps (developing from pycnidia), scattered or nearly so, from innate sessile, minute, up to 0.5 mm diam., black, disk convex, margin hardly visible. Hymenium very narrowly olivaceous, not sparse, otherwise discolored, pure transparent, 95-100 nm high, I+ bluish; paraphyses conglutinate but distinct, simple, septate, tips not swollen. Asci oval-clavate or obpyriform, rounded at the apex and surrounded by a thickened membrane, 8-spored; ascospores in 2-3 rows in ascus, hyaline, simple, ellipsoid, straight, covered with a thin membrane, 9-10 x 3-3.5 µm.
Chemistry. Not reported.
Substrate and Habitat. On exposed rock in maritime and inland areas.
Distribution. Neotropical (Galapagos, Caribbean) north to southeastern North America; in North Carolina found in Piedmont ecoregion.
Schultz, M. (2007) Pyrenopsis. Pp. 286-287 in T. H. Nash, III, C. Gries and F. Bungartz. Lichen Flora of the Greater Sonoran Desert Region. Volume 3. Lichens Unlimited, Arizona State University, Tempe.
Zahlbruckner, A. (1930) New species of lichens from Porto Rico. III. Mycologia22: 69-79 (original description).