FAGACEAE

OAK FAMILY

John M. Tucker

Shrub or tree, monoecious, deciduous or evergreen
Leaves simple, alternate, petioled; margin entire to lobed; stipules small, generally deciduous
Staminate inflorescence: catkin or stiff spike; flowers many
Pistillate inflorescence 1–few-flowered, generally above staminate inflorescence; involucre in fruit generally cup-like or lobed and bur-like, bracts many, generally overlapping, flat or cylindric
Staminate flower: sepals generally 5–6, minute; petals 0; stamens 4–12+
Pistillate flower: calyx generally 6-lobed, minute; petals 0; ovary inferior, style branches generally 3
Fruit: acorn (nut subtended by scaly, cup-like involucre) or 1–3 nuts subtended by spiny, bur-like involucre; nut maturing in 1–2 years
Seed generally 1
Genera in family: 7 genera, ± 900 species: generally n hemisphere. Wood of Quercus critical for pre-20th century ship-building, charcoal for metallurgy; some now supply wood (Fagus, Quercus ), cork (Q. suber ), food (Castanea , chestnut).

QUERCUS

OAK

Evergreen or deciduous
Leaf: stipules small, generally early deciduous
Staminate inflorescences: catkins, 1–several, slender, on proximal part of twig
Pistillate inflorescence axillary among upper leaves, short-stalked; flower generally 1
Staminate flower: calyx 4–6-lobed, minute; stamens 4–10
Pistillate flower: calyx minute, generally 6-lobed; ovary enclosed by involucre
Fruit: acorn, maturing in 1–2 years; nut enclosed by cup-like involucre with thin or tubercled scales
Chromosomes: 2n=24 for all reports
Species in genus: ± 600 species: n hemisphere, to n South America, India
Etymology: (Latin: ancient name for oak)
Many more hybrids have been named but are not included here. Reproduction of many species declining.

Native

Q. kelloggii Newb.

CALIFORNIA BLACK OAK

Tree < 25 m, deciduous; trunk bark becoming deeply furrowed, checkered, dark gray-brown to black
Leaf (6)9–20 cm; petiole (3)10–40 mm; blade widely elliptic, obovate, or ± round, tip generally acute, bristled, margin generally deeply 6-lobed, each lobe with 1–4 coarse, bristle-tipped teeth, upper surface glabrous, bright green, lower surface finely tomentose when young, becoming ± glabrous, pale green
Fruit maturing in 2 years; cup 16–25 mm wide, 15–25 mm deep, generally cup-shaped, scales thin, flat, glabrous to puberulent; nut 20–35 mm, oblong-ovoid, puberulent, tip generally obtuse, shell woolly inside
Ecology: Slopes, valleys, woodland, coniferous forest
Elevation: 200–2400 m.
Bioregional distribution: California Floristic Province (except Great Central Valley, South Coast, Channel Islands)
Distribution outside California: Oregon, Baja California
Hybridizes with Q. agrifolia, Q. wislizeni.
Horticultural information: DRN: 1, 4, 5, 6, 15, 16, 17 &IRR or part SHD: 2, 3, 7, 8, 9, 14, 18, 19, 20, 21.