Ericaceae: Heath Family — Arctostaphylos (Manzanita)
Manzanitas can be extremely challenging to identify with certainty. All have similar flowers and a range of features that frequently overlap more than one species. They are notorious for their proclivity for hybridization, and many examples will be found that will challenge the expert, let alone the layman.
The first thing to look for (though not always easy to see) is whether the shrub has a burl at the base of the main stem. About 30% of all manzanitas have burls, a repository of dormant buds which allows the plant to resprout from the base if the above-ground part of the shrub is destroyed in a wildfire.
Next, one has to consider the leaves; how they are growing, are they mainly erect or are they spreading, are they similar in appearance above and below and are they tomentose (densely white-hairy), glabrous, or something in between? Are they glandular? The shape of the leaves, particularly the tips and the bases, can often help differentiate between species.
The degree of hairiness and the presence or not of glands are other features to consider as is the bark. Several species have shaggy bark but with subtle differences in their appearance.