red oaks

section Lobatae

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 red oaks.

black oaks

A subset of red oaks are informally also called black oaks.

california black oak
Quercus kelloggii

leaf:

9–20 cm
adaxially glabrous, bright green
abaxially finely tomentose, ± glabrous in age, pale green
moderately to deeply lobed, lobes 1–4-toothed, teeth generally bristle-tipped

acorn cap usually about as deep as wide, often covering most of the acorn shell
deciduous
common

coast live oak
Quercus agrifolia

leaf:

2.5–6 cm, roundish
generally adaxially convex, ± dull green
abaxially glabrous to densely tomentose, dull, pale green; sometimes with hair clustered at junction of midvein and lateral veins; typically with 3–5 pairs of lateral veins
tip rounded to spine-toothed
margin rolled under or not, weakly spine-toothed

acorn cap usually about as deep as wide
evergreen
common

interior live oak
Quercus wislizeni

catkins widely spaced, not clustered
leaf:

2–5 cm, roundish or lanceolate
adaxially ± flat
abaxially generally ± shiny, yellow-green, hairless, typically with > 5 pairs of lateral veins
tip generally abruptly pointed, but highly variable among leaves
margin entire to spine-toothed
petiole 3–15 mm, densely hairy on adaxial and abaxial surfaces

nut distally acute to ± obtuse
acorn cap bowl shaped, sometimes as deep as wide
evergreen
common

non-black oaks

coast oak
Quercus parvula

catkins clustered into groups
leaf:

3–9 cm, roundish or lanceolate
adaxially ± flat
abaxially glabrous, generally ± dull, generally with > 5 pairs of lateral veins
tip obtuse to acute or acuminate
margin entire to spine-toothed
petiole 2–25 mm, generally hairy adaxially and almost smooth abaxially

nut distally ± rounded to obtuse (ignoring the little spine on the end)
acorn cap bowl shaped, usually wider than deep
evergreen
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.

2 observed taxons / 2 unobserved taxons / 1 key

Chris’s observations: 29 (19 are research grade)

Locations:

Edgewood Park & Natural Preserve: 4
Henry Coe SP: 4
Castle Rock SP: 3
Bear Creek Redwoods OSP: 2
Calero CP: 2
Alum Rock Park, San Jose
Coyote Lake / Harvey Bear Ranch CP
Coyote Valley OSP
Dr. Aurelia Reinhardt Redwood RP
Huddart CP
Jacks Peak CP
Long Ridge OSP
Monte Bello OSP
Mt. Diablo SP
Mt. Madonna SP
Pleasanton Ridge RP
Skyline Ridge OSP
Waterdog Lake & Open Space
Windy Hill OSP

Months:

Aug.: 1
Sep.: 1
Oct.: 1
Nov.: 4
Dec.: 1
Jan.: 1
Feb.: 1
Mar.: 6
Apr.: 6
May: 1
Jun.: 6

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Taxon info: iNaturalist

Bay Area species: iNaturalist