Arnica discoidea

Rayless arnica

Family: Asteraceae · Type: perennial · Native

Rayless arnica is a California native perennial found in northwestern California, the Cascade Range, northern and central Sierra Nevada, southern Sierra Nevada, central western California, western Transverse Ranges, San Bernardino Mountains, western Peninsular Ranges, and Modoc Plateau in chaparral and foothill woodland at elevations of 100 to 1,500 meters. Flowering from May to July, this plant produces yellow disk flowers in discoid heads without ray flowers, creating a distinctive buttonlike appearance. Growing 15 to 60 centimeters tall with generally a single stem that may be branched, it has long and short-glandular hairs covering its structure. Its basal leaves form prominent sterile rosettes, with 3 to 7 pairs of cauline leaves that are lanceolate to ovate, 2 to 12 centimeters long and slightly toothed, becoming smaller toward the stem's tip. The fruit is 6 to 8 millimeters long, covered with forked hairs and stalked glands, topped with a short white plumose pappus.

Habitat: Chaparral, foothill woodland

Bloom period: May-Jul

Elevation: 100-1500 m

Bioregions: NW, CaR, n&ampc SN, s SNH, CW, WTR, SnBr, w PR, MP

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