Hypogymnia heterophylla “Seaside Bone Lichen”
Mt. Tamalpais State Park, Marin County, CA
December 29, 2015
A true coastal species, H. heterophylla is regularly found along the Pacific from California’s North Coastal Redwood Forests through British Columbia. There are three species with a similar growth habit found west of the Cascades. H. heterophylla is characterized by having many dichotomous branches that occur at 45 degrees, forming a series of perpendicular branch patterns. Another species, H. imshaugii, rarely has a similar branching pattern but, when broken open, H. imshaugii has white interiors while H. heterophylla has black interiors. A third species, H. inactiva, also has a similar growth habit and dark interiors, but rarely exhibits perpendicular branches. While both H. imshaugii and H. inactiva are found east to Montana and Idaho, H. heterophylla is restricted to coastal forests only.