Quercus grisea
Overs. Kongel. Danske Vidensk. Selsk. Forh. Medlemmers Arbeider 1854: 171. 1854.
Large shrubs or moderate trees, deciduous or subevergreen, to 10 m. Bark gray, fissured. Twigs gray, 1-2 mm diam., sparsely or densely stellate-tomentulose or tomentose when young. Buds dark redbrown, ovoid to subglobose, 1-2 mm, stellate hairs causing yellowish color, at least on outer scales; stipules persistent, 1-4, subulate, pubescent, at base of terminal buds. Leaves: petiole 3-10 mm. Leaf-blade oblong to elliptic or ovate, (15-) 25-35 (-80) × (7-) 15-30 (-40) mm, thick and leathery, base cordate or rounded, margins minutely revolute, entire or dentate with mucronate teeth, secondary-veins 6-10 on each side, branched, apex acute, sometimes obtuse, rarely rounded; surfaces abaxially dull gray-green or yellowish, minutely stellate-pubescent with interlocking hairs, secondary-veins very prominent, adaxially dull green, very sparsely and minutely stellate-pubescent, secondary-veins slightly raised. Acorns solitary or paired, subsessile or on peduncle 0-30 mm; cup from deeply goblet to deeply cupshaped, 4-10 mm deep × 8-15 mm wide, enclosing to 1/2 nut, scales broadly ovate to oblong, proximal scales slightly or markedly tuberculate and whitish canescent, tips closely appressed, redbrown, thin, glabrate; nut light-brown, ovoid to narrowly ovoid or ellipsoid, 12-18 × 8-12 mm. Cotyledons connate.
Phenology: Flowering spring.
Habitat: Igneous or dolomitic slopes, oak woodlands, juniper woodlands, desert chaparral
Elevation: usually above 1500 m
Distribution
Ariz., N.Mex., Tex., Mexico (Sonora), Mexico (Chihuahua), Mexico (and Durango)
Discussion
Some of the specimens referred to Quercus endemica by C. H. Muller should be placed in Q. grisea.
Numerous hybrids between Quercus grisea and other white oaks, including Q. gambelii, Q. mohriana, Q. arizonica, and numerous species in northern Mexico, have been reported. In the Hueco and Quitman mountains of trans-Pecos Texas, putative hybrids of Q. grisea × Q. turbinella Greene occur.
Selected References
None.