Distribution: West of the Cascades, Vancouver Island to California; eastern foothills of the Cascades from Kittitas County south to the Columbia River
Habitat: Dry prairies and foothills to rocky bluffs
Flowers: April - June
Conservation Status: Not of concern
Deciduous tree 10-20 m. tall, the trunk up to 1 m. in diameter with thick, furrowed and scaly bark; young growth with reddish pubescence.
Leaves alternate, the blades broadly oblong to obovate in outline, bright green on the upper surface, paler and yellowish-pubescent beneath, 5-12 cm. long, deeply lobed to sub-pinnatifid, the lobes 3-7 per side, entire or bluntly 2- or 3-toothed; petioles 1-2 cm. long.
Plants monoecious; staminate flowers in lax catkins, 1 per node in the axils of early-deciduous bracts; perianth 6-lobed half its length; stamens 6-10; pistillate flowers single or clustered, each surrounded by a scaly, cup-like involucre; ovary inferior; styles 3.
Involucre hardens into a shallow cup, up to 2 cm. broad and 1 cm. deep, holding the ovoid to sub-globose acorn, 2-3 cm. long.