white oaks

section Quercus

Member of high-latitude oaks (subgenus Quercus)
oaks (genus Quercus)
beech family (family Fagaceae)
dicots (class Magnoliopsida)
flowering plants (subphylum Angiospermae)

Various species of oak galls can form on white oaks.

valley oak
Quercus lobata

leaf:

margins deeply lobed (sinuses > 50% to midrib), without spines

sinuses typically wider than oregon oak (Quercus garryana).

adaxially often ± shiny, dark green
abaxially fine-tomentose, dull to pale green

acorn cap 10–30 mm deep, often as wide as deep, all scales tubercled
nut 30–50 mm, generally long-conic, distally acute to ± obtuse
common

oregon oak
Quercus garryana

leaf

margins deeply lobed (sinuses > 50% to midrib), without spines

sinuses typically narrower than valley oak (Quercus lobata).

adaxially shiny, dark green
abaxially short-hairy, dull, light green

acorn cap 4–9 mm deep, less deep than wide, proximal scales ± tubercled, distal ± not
nut 20–30 mm, ovoid to ± spheric, distally rounded
uncommon

blue oak
Quercus douglasii

leaf:

adaxially dull, blue-green
abaxially puberulent, pale blue-green
tip generally rounded
margin ± entire, wavy, or ± shallowly lobed (sinuses < 50% to midrib), without spines

acorn cap less deep than wide
common

leather oak
Quercus durata var. durata

leaf:

adaxially convex, dull green
margin wavy, often rolled under, spine-toothed or very pointy toothed

common

nuttall’s scrub oak
Quercus dumosa

leaf:

adaxially [maybe convex?], ± shiny, green
margin ± wavy or not, ± spine-toothed

uncommon

california scrub oak
Quercus berberidifolia

Caution: ID unsure

leaf:

adaxially ± flat to wavy, ± shiny, green
abaxially with minute appressed stellate hairs, dull, pale green
margin mucro- [sharp rib] or spine-toothed

uncommon

Toxicity of acorn, oak (Quercus spp.):
1 – Skin contact with these plants can cause symptoms ranging from redness, itching, and rash to painful blisters like skin burns.
3 – Ingestion of these plants is expected to cause nausea, vomiting, diarrhea and other symptoms that may cause illness but is not life-threatening.

4 observed taxons / 2 unobserved taxons / 1 key

Chris’s observations: 25 (17 are research grade)

Locations:

Edgewood Park & Natural Preserve: 8
Mt. Diablo SP: 3
Sierra Azul OSP: 2
Almaden Quicksilver CP
Calero CP
Coyote Creek Trail
Coyote Valley OSP
Ed R. Levin CP
Fremont Older OSP
Henry Coe SP
Joseph D. Grant CP
Máyyan 'Ooyákma Coyote Ridge OSP
Russian Ridge OSP
Santa Teresa CP
Windy Hill OSP

Months:

Mar.: 1
Apr.: 5
May: 2
Jun.: 0
Jul.: 2
Aug.: 0
Sep.: 2
Oct.: 1
Nov.: 9
Dec.: 2
Jan.: 1

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Taxon info: iNaturalist

Bay Area species: iNaturalist