Quercus hypoleucoides A. Camus
Family: Fagaceae
silverleaf oak,  more...
[Quercus hypoleuca Miq.]
Quercus hypoleucoides image
Max Licher  
Trees or shrubs , evergreen, to 10 m. Bark black, deeply furrowed. Twigs dark reddish brown, 1.5-3 mm diam., pubescent. Terminal buds light chestnut brown, ovoid, 2.5-4.5 mm, glabrous except for ciliate scale margins, occasionally with tuft of hairs at apex. Leaves: petiole 1.5-13 mm, densely pubescent. Leaf blade narrowly ovate to ovate or elliptic, 45-120 × 15-40 mm, base cuneate to rounded, margins strongly revolute, entire or spinose with up to 11 awns, apex acute to attenuate; surfaces abaxially densely tawny- or white-tomentose, adaxially noticeably rugose, glabrous. Acorns annual or biennial; cup deeply saucer- or cup-shaped, 4.5-7 mm high × 6-13 mm wide, covering 1/3 nut or less, outer surface pubescent to sparsely puberulent, inner surface pubescent to floccose, scales appressed, blunt; nut ellipsoid to oblong, 8-16 × 5-10 mm, glabrous, scar diam. 2.5-5.5 mm. Flowering spring. Common in moist canyons and on ridges; 1500-2700 m; Ariz., N.Mex., Tex.; n Mexico. Quercus hypoleucoides reportedly hybridizes with Q . gravesii ( Q . × inconstans E. J. Palmer [= Q . livermorensis C. H. Muller]) (see C. H. Muller 1951). Several specimens from Pima County, Arizona, fall outside the range of typical Q . hypoleucoides , suggesting hybridization with the Mexican Q . mcvaughii Spellenberg (R. Spellenberg 1992).

Plant: tree; to 10 m high, the bark dark blackish-gray; young twigs woolly, dark reddish-brown beneath hairs, becoming glabrous with age, the older twigs gray, more or less smooth Leaves: unlobed, lanceolate to elliptic, 4-11 cm long, 0.8-3 cm wide, 3-5 times as long as wide, densely whitish woolly with stellate hairs beneath, glabrous or subglabrous above, persisting more than 1 year; stellate hairs of lower leaf surface with 10 or more arms; apex acute to acuminate, often mucronate; base acute to obtuse, sometimes oblique; petiole 3-11 mm long, woolly, later glabrescent; midvein raised above, prominent below; lateral veins ca. 9-15, impressed slightly above, prominent below; secondary venation impressed, often obscured by hairs below; blade coriaceous, dark green above, whitish (because of hairs) below; margin entire or less often serrate-dentate INFLORESCENCE: staminate flowers in aments; pistillate flowers solitary or in groups on spikes, these sometimes abbreviated, each pistillate flower with a separate involucre Flowers: mostly wind-pollinated, unisexual, the perianth much reduced or absent; staminate flowers in heads or aments, the perianth greenish, the stamens 4-6; pistillate flowers usually tricarpellate, solitary or in clusters of about 3 or more, subtended individually or in groups by an involucre that develops into a woody cupule enclosing or subtending the mature fruit(s) Fruit: ACORNS 1.5-2 cm long, maturing after second summer; cap ca. 8 mm long, ca. 12 mm wide, woolly within and without; scales not much thickened basally; nut-shell woolly within Misc: In oak and conifer forests; 1100-2700 m (3600-9000 ft); Apr-Jun (young fruits present at any time, mature fruits Aug-Nov) REFERENCES: Landrum, Leslie R. Fagaceae. 1994. J. Ariz. - Nev. Acad. Sci. Volume 27, 203-214
Landrum 1993, Martin and Hutchins 1980
Common Name: silverleaf oak Duration: Perennial Nativity: Native Lifeform: Tree General: Tree to 10 m tall, bark dark blackish-gray, young twigs woolly, dark reddish-brown beneath hairs, becoming glabrous with age, older twigs gray, more or less smooth. Leaves: Unlobed, lanceolate to elliptic, 4-11 cm long, 0.8-3 cm wide, 3-5 times as long as wide, densely white woolly with stellate hairs beneath; persisting more than one year; leathery; apex acute, often mucronate, base acute to obtuse, petiole 3-11 mm long, woolly, later glabrescent; midvein raised above, prominent below; dark green above; margin entire or serrate dentate. Flowers: Staminate flowers in slender aments, perianth 4-7 lobed; stamens 4-12; pistillate flowers solitary or in clusters 2 or 3; ovary inferior. Fruits: Acorns 1.5-2 cm long, maturing after the second summer; cap 8 mm long, 12 mm wide, woolly within and without, scales not much thickened basally; nut shell woolly within. Ecology: Found in canyons, woodlands or in the grasslands from 3,500-9,000 ft (1067-2743 m); flowers April-June. Notes: Distinctive with its acute tip and the white undersides. Ethnobotany: Unknown, but other species in the genus have many uses. Etymology: Quercus is the classical Latin word for oak, thought to be derived from Celtic quer, fine, and cuez, tree, while hypoleucoides means white or pale beneath. Synonyms: None Editor: SBuckley, 2010
Quercus hypoleucoides image
Max Licher  
Quercus hypoleucoides image
Max Licher  
Quercus hypoleucoides image
Sky Jacobs  
Quercus hypoleucoides image
L.R. Landrum  
Quercus hypoleucoides image
Max Licher  
Quercus hypoleucoides image
Patrick Alexander  
Quercus hypoleucoides image
Patrick Alexander  
Quercus hypoleucoides image
Patrick Alexander  
Quercus hypoleucoides image
Sue Carnahan  
Quercus hypoleucoides image
L.R. Landrum  
Quercus hypoleucoides image
Sue Carnahan  
Quercus hypoleucoides image
Arizona State University Herbarium  
Quercus hypoleucoides image
Quercus hypoleucoides image
Douglas Koppinger  
Quercus hypoleucoides image
Sky Jacobs  
Quercus hypoleucoides image
Sue Carnahan  
Quercus hypoleucoides image
Quercus hypoleucoides image
Anthony Mendoza  
Quercus hypoleucoides image
Sue Carnahan  
Quercus hypoleucoides image
Sue Carnahan  
Quercus hypoleucoides image
Douglas Koppinger  
Quercus hypoleucoides image
Ana L. Reina-Guerrero  
Quercus hypoleucoides image
Anthony Mendoza  
Quercus hypoleucoides image
Sue Carnahan  
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Wood, Sara  
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
Quercus hypoleucoides image
The National Science Foundation
This project made possible by National Science Foundation Award 1410069