Hypericum perforatum subsp. perforatum

Klamathweed, Klamathweed

Family: Hypericaceae · Type: perennial · Not Native

Conservation status: Cal-IPC Yes

Klamathweed is a naturalized perennial herb found in northwestern California, the Cascade Range, northern and central Sierra Nevada, and Sacramento Valley in open, disturbed areas at elevations of 6 to 1,980 meters. Flowering from May to August, this plant produces bright yellow flowers with dense black gland dots that twist and fade with age, arranged in clusters of 25 to 100 per stem. Growing with erect stems 30 to 120 centimeters tall, emerging in many clusters from the base with sterile axillary branches. Its narrow oblong leaves have distinctive rolled margins and are marked with black and clear dots, particularly noticeable on the lower surface. The fruit is unlobed and approximately 7 to 8 millimeters long.

Habitat: Open, disturbed areas in many plant communities

Bloom period: May-Aug

Elevation: 6-1980 m

Bioregions: NW, CaR, n&ampc SN, ScV (uncommon s SN, CW, 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.