Oaks of the World

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  Quercus microphylla

Née 1801 Anales Ci. Nat. 3: 264

Diagnosis here

Synonyms frutex Trelease 1924 Mem. Natl. Acad. Sci. 20: 82 Diagnosis here
frutex var. uhdeana Trel. 1924
macrocarpa Endl. 1848, nom. illeg. not Michx. 1801
microphylla var. uhdeana (Trel.) A.Camus 1939
repanda Benth. 1840, not Bonpl. 1809
Local names 
Range Mexico (Aguascalientes, Durango, Guanajuato, Hidalgo, Jalisco, Nuevo Leon, Oaxaca, Puebla, Querétaro, Tamaulipas, Tlaxcala, Veracruz, Zacatecas) ; 2000-3000 m ;
Growth habit small shrub 0.4-1 m tall, branched even at base of trunk;
Leaves 1-3 x 0.7-1.8 cm; deciduous; coriaceous; elliptic more or less narrowly, or oval; apex obtuse or rounded, often mucronate; base rounded or subcordate; margins slightly revolute, entire or slightly toothed near apex (1-2 pairs of teeth); lustrous grey-green, rough above, with stalkless 6-8 rays stellate hairs; yellowish persistent tomentose beneath (fascicled stalkless trichomes with up to 15 rays); 4-7 veins pairs prominent beneath; epidermis bullate and papillose, whitish; petiole tomentose 2-4 mm;
Flowers pistillates flowers on a tomentose peduncle reaching 1cm long, 1mm thick;

acorn 1-1.5 cm; globose to ovoid; mucronate; stalkless; singly or paired; enclosed 1/3 by scaly, half-round or flattened conical cup; rippening first year, from August to September;

Bark, twigs and

bark fissured, not scaly, dark; twigs 1-4 mm in cross-section, glabrescent the second year; bud ovoid to globose, 1-2mm, brown, obtuse, with ciliate scales; lenticels unconspicuous;
Hardiness zone, habitatnot hardy; prefers dry places;

-- A. Camus : n° 242;
-- Sub-genus Quercus, Section Quercus, Series Leucomexicanae, Group Microphyllae;

-- Q. frutex is considered as a separate species by some Mexican Authors (S. Romero Rangel 2002, S. Valencia-A., 2004, The Plant List 2013), differing from Q. microphylla in having taller height (to 3 m), scally bark, densely and persistently (nearly 2 years) tomentose twigs 1-2 mm in diameter, longer leaves (1.8-6 x 1-2 cm), foliar apex mucronate, margin revolute, lower face less tomentose (stipitate fasciculate hairs with only 5-9 rays), acorn never globose; at 2300-3000 m in Mexico ((Mexico, Hidalgo, Jalisco, Michoacan, Puebla, Queretaro, San Luis Potosi, Tlaxcala, Veracruz). Only the variety uhdeana Trel. stays as synonym of microphylla.

-- Possible confusion with Q. striatula but this species has subcoriaceous, 0.5-2 cm x 0.3-0.7 leaves, margins flat, and is not taller than 1 m;

Subspecies and