Quercus kelloggii


Pacif. Railr. Rep. 6: 28, 89, fig. 6. 1859.

Common names: California black oak
Synonyms: Quercus californica (Torrey) Cooper Quercus tinctoria var. californica Torrey
Treatment appears in FNA Volume 3.

Trees, deciduous, to 25 m. Bark dark brown to black, ridges broad, irregular. Twigs brown to red-brown, (1.5-)2-3.5 mm diam., glabrate. Terminal buds chestnut brown, ovoid, 4-10 mm, glabrous or with scales ciliate on margins. Leaves: petiole 10-60 mm, glabrous to densely pubescent. Leaf blade ovate or broadly elliptic to obovate, 60-200 × 40-140 mm, base cordate to obtuse, occasionally rounded, margins with 7-11 lobes and 13-45 awns, lobes acute to distally expanded, separated by deep sinuses, apex acute; surfaces abaxially glabrous with small axillary tufts of tomentum to densely pubescent, adaxially glabrous to minutely pubescent, veins raised on both surfaces. Acorns biennial; cup saucer-shaped to deeply bowl-shaped, 13-27 mm high × 20-28 mm wide, covering 1/2-2/3 nut, outer surface glabrous to sparsely puberulent, inner surface 1/3 to completely pubescent, scales more than 4 mm long, attenuate or acuminate to acute, smooth, occasionally tuberculate near base of cup, tips loose, especially at margin of cup; nut oblong to broadly ellipsoid, 21-34 × 14-22 mm, puberulent, especially at apex, scar diam. 5.5-10.5 mm. 2n = 24.

Phenology: Flowering late spring.
Habitat: On slopes and valleys of hills and mountains
Elevation: 300-2400 m


The abundant crops of acorns from Quercus kelloggii were at one time an important food source for Native Americans.

The species reportedly hybridizes with Quercus agrifolia (= Q. ×ganderi C. B. Wolf) and Q. wislizenii (= Q. ×morehus Kellogg).

Selected References


Lower Taxa

... more about "Quercus kelloggii"
Kevin C. Nixon +
Newberry +
California black oak +
Calif. +  and Oreg. +
300-2400 m +
On slopes and valleys of hills and mountains +
Flowering late spring. +
Pacif. Railr. Rep. +
Endemic +  and Illustrated +
Quercus californica +  and Quercus tinctoria var. californica +
Quercus kelloggii +
Quercus sect. Lobatae +
species +