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Jepson Interchange (more information)
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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).



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.


Q. john-tuckeri Nixon & C.H. Mull.


Shrub 2–5 m (sometimes tree-like, < 7 m), evergreen; young twigs finely tomentose
Leaf 1.3–2.8 cm; petiole 1–4 mm; blade oblong, elliptic, or obovate, base rounded to widely wedge-shaped, tip obtuse to rounded, margin irregularly spine-toothed, upper surface dull, gray-green, lower surface finely hairy, pale gray-green
Fruit maturing in 1 year; cup 10–15 mm wide, 5–7 mm deep, thin, obconic to hemispheric, scales flat to slightly tubercled; nut 20–30 mm, ovoid to conic, tapered to tip, shell glabrous inside
Ecology: Slopes on desert borders, chaparral, pinyon/juniper woodland
Elevation: 900–2000 m.
Bioregional distribution: Tehachapi Mountain Area (e slope), Inner South Coast Ranges, Western Transverse Ranges (n slope), San Gabriel Mountains (n slope), sw edge Mojave Desert
Synonyms: Q. turbinella Greene subsp. californica J. Tucker
Hybridizes with Q. berberidifolia, Q. douglasii, Q. lobata.
Horticultural information: DRN, SUN: 7, 8, 9, 11, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.

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