Species description: Thallus small to medium but not minute; lobes averaging to more than 1.5 mm wide, always dorsiventral; isidia present or absent, distinctly wrinkled upper surface AND Lobe margins naked; isidia, if present, naked AND Lobes broad or, if elongate, then never both erect and terminating in distinctly swollen tips; lobe tips averaging to less than 0.2 mm thick when moist, seldom strongly wrinkled when dry; habitat and distribution various AND Lower surface naked or bearing scattered tufts of hair at points of attachment, never distinctly woolly AND Isidia and/or lobules present over upper surface AND Thallus distinctly thin, averaging to less than 0.1 mm thick when moist; distribution various AND Isidia partly flattened and lobulate at maturity
OR
Thallus small to medium but not minute; lobes averaging to more than 1.5 mm wide, always dorsiventral; isidia present or absent (Note: all lichens having a distinctly wrinkled upper surface key here) AND Lobe margins naked; isidia, if present, naked AND Lobes broad or, if elongate, then never both erect and terminating in distinctly swollen tips; lobe tips averaging to less than 0.2 mm thick when moist, seldom strongly wrinkled when dry; habitat and distribution various AND Lower surface naked or bearing scattered tufts of hair at points of attachment, never distinctly woolly AND Isidia and lobules absent over upper surface AND Lobes short or elongate, margins not at all turned under; lobe tips not at all horn-shaped AND Upper surface only weakly wrinkled; lobe margins even to weakly lobulate AND Ecology not as above; cellular cortex present AND Lobes distinctly elongate; upper surface mostly smooth; apothecia rare; over mossy rock in hypermaritime sites
Comments: As defined here, L. californicum unites both isidiate and nonisidiate forms. It also appears to freely intergrade with L. lichenoides which is typically a much more wrinkled and lacerate species. Further work is needed.
