Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, usually continuous, rather thick, rimose; prothallus: absent surface: pale gray, warted or wrinkled Apothecia: flat, c. 0.5 mm in diam. disc: dull black margin: dull black, distinct, level with with disc, persistent exciple: with crystals along rim and as radiating clusters in the interior of the exciple, interior colorless except innermost part which is merging with hypothecium pigmentation, edge brown (K-), fading below epithecium: ±brown (K-) and inspersed with crystals in distinct layer hymenium: hyaline, c. 75 µm tall; paraphyses: c. 1.5 µm wide in mid-hymenium, apices ±clavate, 1.5-4 µm wide, some with distinct hoods of brown pigment hypothecium: brown (K-) asci: clavate, Lecanora-type, 8-spored ascospores: hyaline, 5-septate, acicular with both ends pointed, straight to curved, c. 30 x c. 2.5 µm Pycnidia: not seen Spot test: unknown Secondary metabolites: unknown. Habitat and ecology: on bark World distribution: unknown Sonoran distribution: known only from the type collection from southern coastal California (San Diego). Notes: The main characteristic that makes Bacidia jacobi stand out are its ascospores with both ends pointed (as opposed to having one narrow and pointed and one thick, blunt end as in most Bacidia). The generic affinities of B. jacobi are unclear. It does not belong in Bacidia or even in the family Ramalinaceae. Bacidia jacobi in the sense of Hasse (1913) corresponds to B. veneta.