Quercus wislizeni A.DC.

California; Mexico; 300 - 1900 m; introduced in Europe in 1874;

usually a shrub, but may reach 20 m, with trunk to 1.5 cm in diameter; numerous branches; broad open crown;

2.5-5 x 1.2-3 cm; evergreen; leathery; flat (i.e. not rolled under), elliptic or oval lanceolate; apex more or less pointed; base obtuse, or sometimes cordate; margin entire or with small, awn-shaped teeth (to 16); both sides hairless; dark lustrous green above; yellowish green beneath; petiole 3-20 mm long, hairless or weakly pubescent;

male flowers in March-April, on 3-6 cm long catkins;

acorn 2-4 cm long, 0.8-1.4 cm wide; narrowly ovoid and gradually tapered at apex; hairless; sessile; both sides of cup slightly pubescent; cup enclosing 1/3 to 1/2 (sometimes 2/3) of nut, with flat, pointed scales free at their tip.

hardy; occurs on arid slopes; all types of soils; slow-growing;

– A. Camus : n° 298; – Sub-genus Quercus, section Lobatae, Series Agrifoliae; – Discovered by Adolf Wislizenus (1810-1889) = physician of St Louis, of German origin, botanist and friend of G. Engelmann; – Related to Q.kelloggii and to Q.agrifolia (with which it forms hybrids) – Resembles Q.parvula , but the latter has stalked acorns and dull upper surface of leaves; Q.parvula deserves a species rank;