|Author||Greene 1889 Ill. W. Amer. Oaks 1: 32|
|Local names||Engelmann's oak; mesa oak ; evergreeen white oak ;|
|Range||Northeast California, Santa Catalina Island; Mexico; to 1200 m; restricted area;|
|Growth habit||reaches 15 m high, with trunk to 70 cm in diameter; branches low on the trunk; crown open, spreading;|
|Leaves||2.5-7 x 1.2-2.5 cm; evergreen or nearly so (leaves may fall during drought summers); oblong or elliptic; thick, leathery; apex rounded; base variable; margin entire or minutely dentate near apex; blue green, glabrous, smooth, not rough above; yellow green beneath with stellate trichomes with long rays, persisting at least on the base of midrib; 7-8 vein pairs, inconspicuous; petiole 3-7 mm;|
|Flowers||male flowers in April-May on 3-4 cm catkins;|
|Fruits||acorn 1.5-2.5 cm long, pale grey, elliptic, subsessile, striate near apex; single or paired, on a very short rachis; cup enclosing 1/3 to 1/2 of nut, strongly warty near the base; maturing in 1 year;|
Bark, twigs and
|bark light grey, finely striate; twigs stiff, brown, hairy; bud red brown, globose, glabrous, 1-2 mm;|
|Hardiness zone, habitat||almost hardy (zone 8 but withstands -14°C); all types of dry and hot soils, but thrives better in moist ones;|
Sub-genus Quercus, Section Quercus, Series Leucomexicanae, Group Glaucoideae;
-- A. Camus : n° 181 ;
-- Threatened (IUCN Red List Category : EN).
-- Closely related to Q.oblongifolia Torr., and maybe conspecific, with cup scales deeper, larger and more warty;
-- George Engelmann (1809-1884) was botanist at Saint-Louis, of German origin;
-- Hybridizes with Q.dumosa and Q.lobata.