Oaks of the World

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  Quercus deserticola
Author

Trel. 1914 Mem. Natl. Acad. Sci. 20: 79

Diagnosis here

Synonyms alveolata Trel. 1924 Diagnosis here
bipedalis Trel. 1924 Diagnosis here
tamiapensis C.H.Mull. 1942
texcocana Trel. 1924   (A. Camus : 247) Diagnosis here
vallicola Trel. 1924 Mem. Natl. Acad. Sci. 20: 81 (A. Camus : 246) Diagnosis here
Local names encino tecux; encino chico;
Range Mexico (D.F., Guanajuato, Hidalgo, Jalisco, Mexico, Michoacan, Puebla, Queretaro, Sinaloa); 1100 - 2800 m ;
Growth habit rarely exceeding 3 m (may sometimes reach 10 m); crown spreading, wider than high;
Leaves 4-9 x 1.5-3 cm; deciduous or semi-evergreen; leathery, rough; oblong, oboval or elliptic; apex rounded or obtuse, mucronate; base rounded sometimes cordate; margin revolute, thick, entire or undulate or crenate-dentate, with 2-5 pairs of lobes or teeth with straight mucro 0.3-0.5 mm long; dark yellow-green above with some scattered stipitate multiradiate 7-11 rays hairs, especially along midvein; paler below, glaucous, with dense, pediculate, stellate pubescence and some glandular hairs; épidermis slightly bullate; 6-9 vein pairs, slightly curved, impressed above, prominent beneath; petiole tomentose, 2-6 mm long, thickened at base;
Flowers

in April-May; 18-20 male flowers on a 2-3 cm long rachis; pistilate flowers 3-10 together on a 3 cm long peduncle, densely pubescent;

Fruits acorn 1.5 cm, ovoid; 1 to 3 together, on a stout, tomentose, 0.3-1 cm long stalk; enclosed 1/3 in the cup; cup half-round, 1.4-2 cm wide, with scales obtuse covered with white pubescence ; stylopodium persistent ; maturing in 1 year, from August to October;

Bark, twigs and
buds

bark sulcate, grey or dark coffee, with conspicuous lenticels on old twigs; twigs 1.5-3 mm thick, with dense, yellow, persistent tomentum; bud subglobose, pale coffee, hairy, 2-4 mm; stipules 3-9 mm long, reddish, persistent;

Hardiness zone, habitat not quite hardy (zone 8); dry, rocky soils ;
Miscellaneous

-- A. Camus : n° 251;
-- Sub-genus Quercus, Section Quercus, Series Leucomexicanae;
-- Resembles Q. grisea, but this one is much taller, has ovoid buds, 2-4 cm long leaves with stalkless stellate trichomes abaxially; resembles also Q. praeco which has stellate trichomes abaxially, raised veins above, the rim of the cup invaginate. Possible confusion as well with Q. laeta which has glabrescent twigs, the margin of the blade not ou remotely revolute, the abaxial face of the blade with sessile trichomes on the papillose epidermis.

 

Subspecies and
varieties

--
Q.vallicola is considered by some Authors (Govaerts & Frodin), as true species, but not by today's Mexican Authors (Susana Valencia-A., 2006); in 2006, this Author considers Q. texcocana and Q. tamiapensis as synonyms of Q.depressipes.

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