The archetypal oak grows large and spreads wide, with muscular, near-horizontal lower branches that seem to defy gravity. But the group’s 500 species, all native to the Northern Hemisphere, also include upright, pyramidal, and shrubby oaks; in fact, “chaparral” comes from chaparra—Spanish for a dwarf evergreen shrub oak. Oak leaves can be deciduous or evergreen (the latter are called live oaks); lobed, toothed, or smooth edged; but they’re always arranged in an alternate pattern along stems. Some have terrific fall color. All oaks produce inconspicuous flowers followed by acorns, whose single nuts have cuplike caps covered with closely set scales. Some kinds of acorns are edible and sweet, while others are bitter and unpalatable.
Oaks come in two broad categories: white oaks have acorns that mature during the season in which they are produced, and often have leaves with rounded lobes; red and black oaks have acorns that take two seasons to mature, and often have leaves with pointed lobes. Each group can hybridize only within itself.Quercus emoryi
This evergreen tree is native from Arizona to Texas and adjacent Mexico. Handsome and rounded, it grows to 50 ft. tall and 40 ft. wide. Leathery dark green, oval, sharply toothed leaves to 2–3 in. long are holly-like but flat; they turn golden and drop just before new growth begins in late spring. Round-tipped, oblong, edible acorns are enclosed by up to one-half in bowl-like cap. Grows well in low desert areas; tolerates a variety of soils. Needs periodic summer soakings.
Native to southwestern U.S. and northern Mexico. Small tree or shrub with dense, spiny growth to 18 ft...
Native to southern Arizona, Baja California, and Mexico. Leaves to 4 in. long.
Evergreen shrub, native to Arizona. Grows slowly to 3–10 ft. tall and wide. Dark gray-green leav...