Engelmann Oak, Mesa Oak, Pasadena Oak
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 engelmannii
This evergreen tree is native to Southern California. It has a spreading habit to 40–50 ft. tall, often twice as wide. Thick, leathery, dull bluish green, oval or oblong leaves are wavy surfaced or flat, usually smooth edged. Oval to cylindrical, round-tipped acorns to 1 1/4 in. long are half-enclosed in a warty cap. Tree grows best with monthly deep soakings in warm season, but don’t keep it constantly moist. In its native area, it has the same cherished native status as the more widespread Q. agrifolia. Not susceptible to sudden oak death.
Bushy grower to 1–2 ft. high and 1–1 1/2 ft. wide, with furry gray-green leaves and 1 1/2-...
Deciduous shrub. Native to Coast Ranges in Southern California. Grows to 6–9 ft. tall and 4&ndas...
Perennial, from moist lowlands in South America. Upright, dense grower to 4–6 ft. tall and 3&nda...