Ericaceae: Heath Family — Arctostaphylos (Manzanita)
The Heath family is mostly chaparral shrubs with alternate evergreen leaves. Examples are Arctostaphylos (Manzanita), Vaccinium (Huckleberrry), as well as trees, such as Arbutus (Madrone). All these have pendulous, bell- or urn-shaped flowers. The family also includes Rhodododendron and Azalea, with showy, funnel-shaped flowers. Most prefer acidic soil.
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 hybridizing, which results in a mix of features. 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 one, and they resemble a rounded, knotty platform. Caution: if old leaves are piled up on the burl, it may be hard to see. A burl is 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 on both surfaces? 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.
Other features to consider are the degree of hairiness, the presence or absence of glands, and the bark. Several species have shaggy bark, but with subtle differences in their appearance.