Thallus: crustose, cottony, leprarioid, caespitose in early stages, later widespreading forming up to a few mm thick patches to several cm (sometimes a diameter or more) wide, dull, pale lime-green, composed of colorless, anastomosing hyphae 2.5-5 µm and, especially in upper part, of soredia-like, irregular clusters to 15(-20) µm comprising a few algal cells surrounded by hyphae medulla: not evident photobiont: coccoid, green; cells 4-6(-8) µm in diameter Spot tests: all negative Secondary metabolites: lesdainin, and ±a range of unidentified terpenoids (mostly in traces and sometimes not evident; zeorin possibly present). Substrate and ecology: in shallow and shaded rock cavities and crevices in canyons, 1335 to 1540 m World distribution: as for the genus Sonoran distribution: Arizona (northern Gila Co. and Coconino Co.). Notes: Zeorin has been reported by Canals et al. (1997), but Tønsberg (2002) could not positively find zeorin in material in 7 specimens analyzed from Europe, North America and Asia. Botryolepraria lesdainii may be confused with Lepraria lobificans; but that species has a distinct white medulla, sometimes distinct lobes, and a chemistry including stictic acid, zeorin and atranorin.