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  Quercus pinnativenulosa

C.H.Muller 1936 J. Arnold Arbor. 17: 171

Diagnosis here

Local names
Range Mexico, endemic to the Sierra Madre Oriental (Hidalgo, Nuevo Leon, Oaxaca, Querétaro, San Luis Potosi, Tamaulipas and Veracruz); 800-1900 m;
Growth habit 7-20 m tall, trunk to 0.5 m in diameter;
Leaves 6-13 x 1.8-3 cm; more or less leathery; lanceolate to elliptic-lanceolate; apex acuminate with long bristle-tip, often in a spiral; base acute, seldom rounded; margin entire, sometimes slightly undulate and even remotely rolled under (old trees); yellowish green, lustrous, hairless above; hairless beneath; somewhat concolor; 8-18 vein pairs, angled more than 45° with the midvein , flat or impressed above but not conspicuously, flat or weakly raised below; epidermis smooth, slightly papillose ; petiole 5-17 mm long, glabrous;
Flowers in March-April; male catkins 6-9 cm long, with some unicellular hairs, lax; female inflorescence 5-8 mm long, most often 2 flowered;
Fruits acorn 1-1.8 cm long, 1 cm wide; solitary or paired on a 5-8 mm long stalk; nut enclosed 1/3 by cup; cup half-round with straith margin, 0,7-0,9 cm wide, with triangular, pubescent scales; maturing in 2 years from August to October;

Bark, twigs and

twig 1.4-3 mm in diameter, hairless, greyish, silky, slightly sulcate, with inconspicuous, yellowish lenticels; buds narrowly conical or ovoid, 3-4.5 mm long x 1.3-1.7 mm wide, with greyish, glabrous scales and apex pointed; stipules linear 1-1,3 cm long, hairy at margin, deciduous;

Hardiness zone, habitat mixed cloud mountain forests (with Q.affinis, Q.polymorpha) ; withstands -16°C;
-- A. Camus : n° 353;
-- Sub-genus Quercus, section Lobatae, Series Erythromexicanae, Group Eugeniaefoliae;
-- Not well known; area restricted;
-- Closely related to
Q.salicifolia Liebm., from which it differs in having narrower leaves (2-4 cm for salicifolia) longly acuminate at apex, base cuneate (round for salicifolia), veins less prominent beneath, petiole longer (1-6 mm for salicifolia), stipules longer (5 mm for salicifolia), and acorns maturing in 2 years (annual for salicifolia);
-- Q. pinnativenulosa is distinguished from Q. delgadoana by its leaves with a flat, not revolute, margin, shiny adaxially and with secondary veins flat (not impressed); Q. delgadoana has leaves with a revolute margin, dull and glaucous adaxially and the veins are impressed on the adaxial blade surface.

Subspecies and