Oaks of the World

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  Quercus macvaughii
Author Spellenb. 1992 Amer. J. Bot. 79: 1200
Synonyms fulva auct. not Liebm.
Local names  
Range Mexico (Chihuahua, Durango, Sonora, San Luis Potosi) ; 1500-3100 m;
Growth habit reaches more than 20 m tall; sometimes shrubby;
Leaves 6-15 cm long, 4-107 wide; broadly oboval or rounded; leathery; thick; convex; apex obtuse or rounded, seldom acute or acuminate, bristle-tipped; base progressively attenuate, abruptly rounded or slightly cordate, sometimes truncate; margin thick, revolute, cartilaginous, with 3-7 pairs of small teeth, ending in 2 mm long bristle, seldom margin subentire; dark green, lustrous, nearly hairless above, except fascicled and glandular hairs along midrib; dense tomentum beneath, yellowish white, made of numerous 4-10 rayed, sinuous, tangled fascicled trichomes, with a lot of white and yellow glandular hairs; 6-10 vein pairs slightly curved, strongly impressed adaxially; epidermis slightly bullate and papillose, invisible under tomentum; petiole 1-3.5 cm long, persistently tomentose; 
Flowers in April-May; male catkins 3-8 cm long, few-flowered; female ones bearing 1 or 2 flowers;
Fruits acorn 1-2 cm long; subsessile or on a 0.5-1 cm long peduncle; singly or paired; cup pubescent, margin not rolled under, 9-11 mm in diameter, enclosing 1/3 of nut; maturing in 2 years between July and September; 

Bark, twigs and
buds

bark dark grey, fissured; twig 3-8 mm thick, sulcate, with dense, purple, stellate tomentum at first, then becoming golden, dwindling with years; small, flat lenticels; bud 3-4 mm long, ovoid, hairy near apex; stipules 6-9 mm long, soon deciduous;
Hardiness zone, habitat probably hardy;
Miscellaneous -- Sub-genus Quercus, section Lobatae; 
-- Related to Q.crassifolia,of which it is a variety for Zavala-Chavez, 2003;
-- Possible confusion with Q. crassifolia, Q. fulva and Q. conzattii; Q. crassifolia differs in having the pedicel of abaxial trichomes longer (0.2 mm); Q. conzattii differs in the annual maturation of acorn, the cupule peduncle longer (10-15 mm), and more acorns on the same peduncle (to 5 or more); Q. fulva has a cupule 13-18 mm in diameter with margin rolled inside, and the abaxial foliar trichomes with 10-25 rays, 0.4-0.7 mm long;
Subspecies and
varieties
 
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