Grevillea robusta

Silkoak

Family: Proteaceae · Type: perennial · Not Native

Conservation status: Cal-IPC Yes

Silkoak is a naturalized perennial tree found in southern Coastal Ranges, southern California, and Peninsular Ranges on brush-covered hillsides and in canyons at elevations below 450 meters. Flowering from March to May, this plant produces orange and yellow flowers in one-sided inflorescences with spreading pedicels. Growing up to 30 meters tall with a distinctive branching structure, it develops a robust canopy with complex foliage. Its large compound leaves are 15 to 40 centimeters long, featuring pinnately divided leaflets that are green on top and silvery-hairy underneath. The fruit is flat and winged, containing one to two seeds with a persistent style.

Habitat: Escaped from cultivation, brush-covered hillsides, canyons

Bloom period: Mar-May

Elevation: < 450 m

Bioregions: s SCoRO, SCo, PR

California counties: Los Angeles, Orange, San Luis Obispo, Ventura, San Diego, Alameda, Santa Clara

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.