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.

Source:  Lichens of British Columbia