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.

[1] Arctostaphylos myrtifolia is a red-barked, bristly shrub reaching just over a meter in maximum height.

The small bright green leaves are coated in tiny glandular hairs and are shiny but rough in texture.

[4] These microorganisms, as well as a newly identified one, Phytophthora cambivora, are spreading rapidly and may soon reach the entire range of the plant's distribution.

Because of this threat, which may lead to the extinction of the species, the United States Fish and Wildlife Service has recommended that it be upgraded from threatened to endangered status.