Oaks of the World

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 Quercus grisea
AuthorLiebm. 1854
Synonymsundulata Torr. var. grisea (Liebm.) Engelm. 1877
oblongifolia Coult., not Torr. 1853, nor R.Br. ter 1871
Local namesscrub oak, gray oak ; mountain white oak ;
Range Southwest Texas; North and Center of Mexico; 1500-2700 m;
Growth habit4-7 m, sometimes to 10 m, but smaller in cultivation; trunk short, 10-30 cm wide;

2-4 x 1-3 cm; semi-evergreen; thick, stiff; oboval or oblong-elliptic; apex pointed or obtuse, mucronate; base rounded to cordate; margin entire or often when youth crenate-dentate, with 1-4 pairs of mucronate teeth; glaucous grey, slightly lustrous above with stalkless, stellate hairs; greyish green , hairy beneath, with dense, stalkless, stellate trichomes; 6-10 vein pairs, remotely raised above or sometimes slightly impressed, prominent beneath; epidermis papillose; petiole pubescent, 2-8 mm long;

Flowers in April; male catkins 4-7 cm long, with more than 20 pubescent flowers; female inflorescences 1-4 cm, with 1 to 8 flowers slightly tomentose;
Fruits acorn 1.2-2 cm long; singly or paired or more; short peduncle 0-3 cm long; cup half-round, greyish tomentose, enclosing 1/2 of nut; cup scales with base thickened; maturing in 1 year from October to December; cotyledons connate;

Bark, twigs and

bark light grey, furrowed into plates; young twigs smooth, yellowish tomentose, glabrescent; buds dark red brown, ovoid, glabrous, 1-2 mm long, covered with yellowish stellate hairs; persistent stipules, 3-6 mm long, pubescent;
Hardiness zone, habitatzone 7-8; prefers dry, rocky soils;
Miscellaneous-- A. Camus : n 179;
-- Sub-genus Quercus, Section Quercus;
-- Possible confusion with Q. chihuahuensis but this species has abaxial foliar trichomes fascicled stipitate;
Subspecies and

Q.grisea is actually a complex of two species :

--- 1/ Q.grisea Liebmann
= gray oak, mountain white oak ;
it is the type described above;
the specimens named Q.endemica C.H.Muller 1937 are actually identical;
several hybrids with : Q.gambelii, Q.mohriana, Q.arizonica, Q.turbinella;

---2/ Q.arizonica Sargent 1895 : see this word