bearberries and manzanitas

genus Arctostaphylos

Member of heath family (family Ericaceae)
dicots (class Magnoliopsida)
flowering plants (subphylum Angiospermae)

Calflora lists 67 species and subspecies of manzanita in the bay area. I've discarded the rare ones, but it's still tough to distinguish among those that remain.

Per Monterey County Wildflowers, “Manzanitas are difficult to identify. 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.”

Key features:

burls at base of trunk or not [figure]
leaf color and features on each side
leaf clasping or not
leaf sticky or not
shape of nascent inflorescence bracts
inflorescence shape
flower parts in 4s or 5s
ovary/fruit features and diameter

Hosts bearberry and manzanita galls.

burl; leaves different on each side

bearberry
Arctostaphylos uva-ursi

plant prostrate, 10–50 cm
may or may not have a burl at the base of main stem (or above) from which new buds can sprout after a fire

may be hidden by fallen leaves

leaf:

adaxially dark green
abaxially light green, shiny, sparsely puberulent or glabrous

uncommon, mostly near San Bruno, but scattered elsewhere

pacific manzanita
Arctostaphylos pacifica

plant prostrate, 10–60 cm
burls on stems
leaf:

adaxially dark green sparsely hairy
abaxially light green

rare

brittleleaf manzanita
Arctostaphylos crustacea

plant erect, 1–3 m
burl prominent at base of main stem
leaf:

adaxially dark green, glabrous
abaxially light green, glabrous to densely short-hairy

common, mostly in the Santa Cruz Range, but also found in the Diablo Range

burl; leaves same on both sides

eastwood’s manzanita
Arctostaphylos glandulosa

plant erect, 1–4 m
leaf bright green to gray-green or strongly glaucous, shiny or dull, pappilate, glandular-puberulent to glandular-hairy

petiole 5–10 mm

uncommon everywhere

found mostly in Marin

no burl; leaves different on each side

glossyleaf manzanita
Arctostaphylos sensitiva

plant erect, 1–2 m
old stem bark smooth, ± red
flower parts in fours
leaf shiny, glabrous with hairy midvein

adaxially dark green
abaxially light green

common in outer coastal range

glossyleaf manzanita
Arctostaphylos nummularia

plant shape and size depends on subspecies
old stem bark generally rough or shredding, gray or red-gray
flower parts in fours
Jepson and iNaturalist have it only north of Pt. Reyes
glossyleaf manzanita (Arctostaphylos sensitiva) was previously considered a subspecies of glossyleaf manzanita (Arctostaphylos nummularia), so e.g. CalFlora is confusing

santa cruz manzanita
Arctostaphylos andersonii

plant tree-like, 2–5 m
old stem bark smooth, ± red
leaf light green
flower parts in fives
common in Santa Cruz Range

pajaro manzanita
Arctostaphylos pajaroensis

plant erect, 1–4 m
old stem bark persistent but shredding, gray or ± red
flower parts in fives
leaf blue-green
very rare on the eastern side of Monterey Bay

no burl; leaves same on both sides; low growing

san bruno mountain manzanita
Arctostaphylos imbricata

plant a prostrate shrub, 10–100 cm
leaf light green, sparsely glandular-hairy

petioles 0–2 mm; leaf base clasping

uncommon

presidio manzanita
Arctostaphylos montana ssp. ravenii

plant prostrate, 10–30 cm
fruit 3–5 mm wide
leaf dark green, shiny, puberulent or glabrous.
rare in Presidio area

franciscan manzanita
Arctostaphylos franciscana

plant prostrate to somewhat mounded, 20–150 cm
fruit 6–8 mm wide
leaf bright green, smooth, ± puberulent or glabrous

petioles 1–12 mm; leaf base not clasping

uncommon

no burl; leaves same on both sides; tall growing

nascent inflorescent bracts fleshy, scoop-shaped or scale-like

hooker’s manzanita
Arctostaphylos hookeri ssp. hookeri

inflorescence 0–1-branched
leaf bright green, shiny, ± puberulent or glabrous
rare around the eastern and southern parts of Monterey Bay

CalFlora has many records in Marin, but these are a subspecies that has been re-classified as mount tamalpais manzanita (Arctostaphylos montana)

big berry manzanita
Arctostaphylos glauca

erect shrub or small tree, 1–8 m
inflorescence a panicle, 4–8-branched
leaf white-glaucous, dull, glabrous
common
mostly SE of highway 17 in the Santa Cruz Range, with significant eastern pockets at Mt. Diablo, Grant, and Coe