64. Quercus john-tuckeri Nixon & C. H. Muller, Novon. 4: 391. 1994.
Tucker oak, desert scrub oak
Quercus turbinella Greene subsp. californica J. M. Tucker
Shrubs , subevergreen or evergreen, 1-3(-5) m. Bark light gray or brown, scaly. Twigs yellowish or dingy gray, 1-1.5(-2) mm diam., densely tomentulose. Buds brown, ovoid or globose, 1.5-2(-3) mm, glabrous except for ciliate margins of scales; proximal scales often yellowish puberulent. Leaves: petiole 1-4 mm. Leaf blade unicolored, elliptic or obovate, (10-)15-30(-40) × (8-)10-15(-20) mm, thick and leathery, often brittle, base truncate or rounded-attenuate, rarely subcordate, margins irregularly spinose-toothed, occasionally shallowly lobate, secondary veins (3-)4-7, often some veins branching near margin and passing into more than 1 tooth, apex acute or rounded; surfaces abaxially waxy grayish, light green, or yellowish, sparse to moderately dense (8-)10-12-rayed, (loosely) appressed-stellate hairs, often 0.2-0.5 mm diam., and sparse to crowded, yellowish, glandular hairs, adaxially dull grayish, with stellate hairs, similar to abaxial surface. Acorns solitary or paired, subsessile; cup cup-shaped or obconic to hemispheric, 5-7 mm deep × 10-15 mm wide, thin, scales whitish or yellowish, moderately or scarcely tuberculate, puberulent; nut fusiform, ovoid, or conic, 20-30 mm, apex acute. Cotyledons distinct.
Dry slopes, chaparral, pinyon and juniper woodlands, margins of oak woodlands and sagebrush; 900-2000 m; Calif.
Endemic to California, Quercus john-tuckeri occurs from Los Angeles County northward in the interior Coast Ranges and Sierra Foothills to the northern edge of Sacramento Valley.
Quercus john-tuckeri bears some resemblance to both Q . turbinella and Q . berberidifolia . Quercus turbinella has pedunculate fruit and cordate leaf bases, however, and Q . berberidifolia has a glabrate adaxial leaf surface, substantially smaller stellate trichomes with fewer rays on the abaxial leaf surface, heavier tuberculate acorn cups, and blunt or rounded (instead of acute) acorns.