Quercus crassipes Bonpl.

Mexico (Guanajuato, Hidalgo, Jalisco, Mexico, Michoacan, Morelos, Oaxaca, Puebla, Querretaro, Tlaxcala); 2000 to 3500 m; introduced in Great Britain in 1839 by Hartweg;

tree or shrub, 4 to 20 m; trunk 0.4-1 m in diameter, sometimes more;

2.5-9 cm x 1-3; deciduous or semi-evergreen; leathery; narrowly elliptic, or lanceolate or oblanceolate; base rounded or subcordate; apex acute, aristate; margin very thick, slightly rolled under, entire or sometimes slightly wavy; young leaves with dense, yellowish tomentum both sides (adaxially mainly on midrib); mature leaves dark greyish green adaxially, hairless (except along midrib or only near its base); abaxially with yellowish grey fasciculate stipitate trichomes (5-6 rayed, stalked, spreading trichomes), persistent but less dense in autumn; 10-20 vein pairs, prominent beneath like the midrib, forked before reaching margin, at an angle of nearly 90° with the midrib; adaxially the midrib is impressed; bullate epidermis; petiole thick, yellowish, tomentose or glabrescent, 2-10 mm long.

in May; staminate carkins 3-6 cm long, bearing 15-20 flowers with 5 stamens 3 mm long, and apiculate anthers; pistillate flowers 1-2 on a short peduncle 0.5 cm long;

acorn 1-2 cm long, ovoid, hairless except at the mucronate apex; singly or paired on a 2-8 mm long peduncle, thicker than the twig that bears it; cup half-round or conical, enclosing 1/3 of nut, with rim usually rolled inside or at least thickened, with thin, slightly tomentose scales triangular at apex; maturing in 2 years, from September to November;

hardy in zone 7; prefers deep, dry soils (not too much);

– A.Camus : n° 315; – Sub-genus Quercus, section Lobatae, Series Erythromexicanae; – Related to Q. confertifolia ; – For some Authors, it is a synonym of Q.mexicana Bonpl. but a confusion is possible as Q. mexicana Benth . 1840, not Bonpl. 1809 is a real synonym of Q. crassipes … – Differs from Q. mexicana Bonpl. in having more vein pairs (to 12 for mexicana ), abaxially an even indumentum (dots of contorted trichomes for mexicana ), cupule with involved margin (erect margin for mexicana ), secondary veins at an angle near 90° with the midrib(less than 80° for mexicana ), and a petiole likely glabrescent (pubescent for mexicana ). – Possible confusion with Q. castanea which has annual fruits, fasciculate sessile trichomes beneath, and 2-5 pairs of teeth in apical part.