Arctostaphylos imbricata is a species of manzanita known by the common name san Bruno Mountain manzanita. It is endemic to san Mateo County, California, where it is known only from six populations on san Bruno Mountain. Despite its rarity, this manzanita is not a federally listed endangered species because five of its six remaining populations are protected by the san Bruno Mountain Habitat Conservation Plan. This is a small, spreading shrub that forms in mounds. The branches are coated in long bristles tipped in resin glands. The light green, glandular leaves are round to oval with rough, bristly, dull surfaces and smooth or toothed edges about 2" long and 1" wide. The dense inflorescence is crowded with rounded, urn-shaped white flowers, each only 1/2" long. The fruit is a hairy drupe about 3/4" wide. This plant grows in the chaparral plant community. Like many other chaparral species, it requires wildfire for reproduction. Fire suppression in its native habitat is one threat to its survival.