Life habit: lichenized Thallus: crustose, rather thin, 100-600 µm thick, sometimes evanescent and then +endophloeodal cortex: c. 20 µm thick, of thick-walled hyphae photobiont: primary one a chlorococcoid green alga, secondary one absent; algal layer: 50-90 µm thick, with arachnoid hyphae composed of 10-15 x 3 µm large cells with c. 1 µm thick walls; algal cells:, subspherical, 6-9 µm in diam. medulla: composed of arachnoid hyphae only, present only when the thallus is sufficiently thick surface: white to dark or glaucous gray, smooth or rugulose, isidia and soredia absent Ascomata: apothecial, sessile, with 2-10 µm thick attachment layer and anchorage bundles originating from the apothecial base and the attachment layer, 0.5-1(-2.5) mm in diam. and 0.35-0.45 mm thick, disc: very variable, black or brown to gray or pale yellow, +white pruinose, sometimes black only in a rim around the disc, dull, initially concave but becoming plane or convex exciple: composed of 3-3.5 µm thick, thick-walled hyphae with c. 1 µm wide lumina; ectal part: 50-80 µm thick, compact, with dense, conglutinated hyphae with 2.5-3.5 µm thick walls and 1-2(-3.5) µm wide, usually with the same dark blue-green pigment as the epithecium in its outer part, sometimes limited to a zone around the disc; medullary part: consisting of loose hyphae and including small aggregates of crystals parathecium: usually indistinct, restricted to outer part of apothecium epihymenium: with diffuse, dark blue-green to olive-green pigment that is most concentrated around the paraphyses tips, but sometimes scarce or lacking hymenium: hyaline, (100-)110-140(-160) µm tall, I+ deep blue to greenish blue, with soft gelatin; paraphyses: 1 µm thick, clearly septate, branched and gradually thickened to 3-4 µm wide; subhymenium: c. 35 µm thick; subhypothecium: not clearly differentiated from the hypothecium, 10-15 µm thick, in the center up to 30 µm thick hypothecium: asci: cylindrical, c. 90 x 20 µm, (1-)2(-4?)-spored; wall: c. 3 µm thick in young asci and c. 8 µm thick in mature asci, K/I+ pale blue with a c. 0.5 µm thick deep-blue outer layer; apical dome: in young asci clear, c. 20 µm thick, mostly without an ocular chamber, dome K/I+ deep-blue, 2-celled ascospores: hyaline, straight, (40-)50-60(-65) x 15-22 µm; wall c. 2 µm thick, septa less thick, with a rather clear central pore; epispore lacking Conidiomata: pycnidial, immersed in small warts with a dark tip, in cross section +circular and c. 0.3 mm in diam.; conidiophores: type II sensu Vobis (1980) conidia: weakly clavate to subbacilliform, c. 3.5 x 1 µm Spot tests: thallus K- or + weakly yellow, C-, KC-, P-, UV- Secondary metabolites: zeorin and atranorin, usually in small amounts or absent. Substrate and ecology: on bark of Pinus, preferring light, mossy forest, but tolerating considerable shade World distribution: neotropical mountains at (850-)1500-3500 m in both North and South America Sonoran distribution: Sierra Madre Occidental in Sinaloa. Notes: Lopezaria versicolor is very variable in many respects, including: size of the apothecia, color and pruinosity of the discs, presence, distribution, and intensity of pigment in the epithecium and ectal exciple See Sipman (1983) for further discussion of the species.