| Quercus oblongifolia | |
| Author |
Torr. 1853 Sitgreaves, Kept., p. 173, pi. 19, 1853 Diagnosis here |
| Synonyms | |
| Local names | Sonoran
blue oak ; Mexican blue oak ; |
| Range | SW
U.S.A. (Arizona, SW New-Mexico, W Texas); North of Mecico (Durango, Sonora,
Chihuahua, Coahuila); to 1700 m; |
| Growth habit | may
reach 15 m, but usually smaller; |
| Leaves |
2.5-7 x 1.5-2.5 cm; semi-evergreen; sub-leathery, stiff; oblong to elliptic, sometimes lanceolate or oval; apex obtuse or broadly rounded; base cordate or obtuse, sometimes acute or cuneate; margin undulate, cartilaginous, entire or seldom with some teeth (shortly mucronate or not) near apex; blue-green above, bloomy at first, sometimes slightly floccose near the base of the midrib, soon hairless except at the base of midvein; paler beneath, yellowish green or glaucous, with some scattered stellate hairs, becoming glabrous at maturity except at the base of the midvein; 7-9 branched vein pairs, prominent beneath, slightly raised above; petiole short (2-6 mm), slender, often reddish and tomentose; |
| Flowers | March-May;
male catkins 2-4 cm long, bearing more than 10 flowers; |
| Fruits | acorn
ovoid 1.2-1.8 cm ; solitary or paired; sessile or on a short peduncle
de 4-12 mm long; enclosed 1/3 by cup; cup with scales greyish pubescent,
slightly warty; maturing in 1 year from September to November; cotyledons
connate; edible; |
|
Bark, twigs and |
bark
light grey, deeply fissured into small square plates; young twigs 1-1.5
mm thick, at first stellate tomentose, becoming hairless, grey to red
brown; older twigs rough, becoming blackish; buds brown, subglobose, 1-3
mm long, scales ciliate on margin; stipules sometimes |
| Hardiness zone, habitat |
hardy (hardiness zone 7); all types of soils; |
| Miscellaneous | --
A. Camus : n° 180; -- Sub-genus Quercus, Section Quercus, Series Leucomexicanae; -- Closely related (or conspecific ?) to Q.engelmannii, but leaves wider (on average 4.5 x 3 cm, instead of 4 x 1 cm for Q.engelmannii); -- No hybrids known; |
| Subspecies and varieties |
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| Pictures |
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