[Wikipedia] Limited Range, Habitat, Endangered: Arctostaphylos myrtifolia is a rare species of manzanita known by the common name Ione manzanita. It is endemic to the Sierra Nevada foothills of California. It grows in the chaparral and woodland plant community on a distinctive acidic soil series, an oxisol of the Eocene-era Ione Formation, in western Amador and northern Calaveras counties.[2] There are only eleven occurrences, of which three have not been recorded since 1976.[3] This is a federally listed threatened species.[1] (link added by Mary Ann Machi)