Chrysolepis is a small genus of evergreen trees and shrubs in the family Fagaceae (order Fagales), endemic to the western United States. It comprises just two species — Chrysolepis chrysophylla (golden chinquapin) and Chrysolepis sempervirens (bush chinquapin) — both known by the common name chinquapin, a name shared with several related genera.
The genus ranges from western Washington south through Oregon and California to the Transverse Ranges of Southern California, extending east into Nevada. Plants bear simple, entire leaves covered in a dense layer of golden scales on the underside and a thinner layer above; the leaves are persistent, remaining on the plant for three to four years before falling.
The fruit is a distinctive densely spiny cupule enclosing one to three sweet, edible nuts. Unlike the related chestnuts (Castanea), in which nuts ripen in three to five months, Chrysolepis nuts require fourteen to sixteen months to mature. The nuts are triangular and fully enclosed in a sectioned cupule — a key character distinguishing the genus from the related Castanopsis, the subtropical southeast Asian genus in which Chrysolepis was formerly placed. Chrysolepis further differs from Castanea in its evergreen habit and the presence of a terminal bud on the shoots.
The edible nuts were historically consumed by indigenous peoples of the western United States, and the fruits also serve as an important food source for chipmunks, squirrels, and other wildlife.
Etymology
The genus name Chrysolepis derives from the Greek chrysos (golden) and lepis (scale), referring to the characteristic dense golden scales coating the underside of the leaves.
Distribution
Chrysolepis is endemic to the western United States, occurring from western Washington south along the Pacific Coast ranges to the Transverse Ranges of Southern California, with populations extending east into Nevada.
Ecology
The spiny cupule fruits of Chrysolepis are an important wildlife food source, consumed by chipmunks, squirrels, and other small mammals. The sweet edible nuts were also traditionally gathered and eaten by indigenous peoples of the Pacific Coast and Sierra Nevada regions.
