Hypericum Perforatum
St. John's-wort  


St. John's-wort has two-sided, rust-red stems and numerous clusters of bright yellow flowers with five distinctly separate petals. Its oblong leaves have prominent veins and are covered with dots which are transparent when the leaves are held up to the light. Mature plants grow to 1 m in height and turn a rusty red.

St. John's-wort invades grazed and disturbed lands. In dense stands, it displaces native plant species and reduces livestock and wildlife forage. The plant also contains a toxin that causes skin irritation and blistering in light-coloured livestock when they are exposed to sunlight.

In British Columbia, St. John's-wort grows at low to mid-elevations in coastal, grassland, and open forested regions, and along roadsides and disturbed areas. It occurs in scattered pockets in the Kootenays, Okanagan, Boundary, North Thompson, Cariboo, Skeena, Fraser Valley, and Vancouver Island areas.

The root system spreads laterally and is capable of forming new buds that separate from the parent. Seeds have a gelatinous coat that facilitates long-distance dispersal.


Weeds BC home Weeds BC home Resources