Quercus × pauciloba
Native to (or naturalized in) Oregon:
- Deciduous or semi-evergreen shrub or small tree, to 10 ft (3 m). Leaves alternate, simple, oblong or elliptical, margins serrate to undulate or shallowly lobed, tapering to base, 2-6 cm long, 1-3 cm wide, dark bluish-green above, dull green and densely hairy below. Fruit (acorn) 1-1.5 cm long with a scaly cup covering about 1/3 of the nut.
- Hardy to USDA Zone 5 Native range from Colorado to New Mexico, Arizona, Utah, Oklahoma and northern Mexico.
The following is from the Flora of North America (http://www.efloras.org/):
Numerous putative hybrid swarms occur throughout the range of Quercus gambelii that involve a number of suspected parental species. Most of these populations have, at one time or another, been referred to as Quercus undulata Torrey. The putative hybrids have serrate or shallowly lobed leaves and considerable variation in habit, leaf pubescence, and acorn morphology. Tucker (1961, 1969, 1971) and Tucker et al. (1961) have identified the major components of the Q. undulata complex as Q. turbinella (western Utah and northwestern Arizona, and central Colorado), Q. grisea (New Mexico and southern Colorado), Q. havardii (southeastern Utah and northwestern Arizona), Q. mohriana (northeastern and southern New Mexico), Q. arizonica (central Arizona), and Q . muhlenbergii (eastern and central New Mexico). Quercus macrocarpa has been implicated as a parent of variable populations in New Mexico (J. M. Tucker and J. R. Maze 1966). Because of the complex variability in these populations, no effort has been made to treat them separately here; indeed, it would be impossible to produce usable keys if these were included as formal taxa.
Tucker, J. M. 1963. Studies in the Quercus undulata complex. III. The contribution of Q. arizonica. Amer. J. Bot. 50: 699-708.
- undulata: wavy, a reference to the leaf margins.