St. Johnswort

Hypericum perforatum

Stems are branching with yellow flowers, petals edged with black dots; opposite leaf arrangement.

Life Forms	Forb
Habitats	Disturbed sites Forest edges Gardens Little Habitats Pastures Prairies Residential yards Roadsides
ODA Listing	B
Soil and Moisture Conditions	Dry to moist Well drained
Suggested Actions	Use BMPs to control on private property
Shade Preference	Full sun Part shade
Mature Height	1-2.5'
Distribution	Widespread in Oregon
Control	Hand pulling is only recommended for very small patches. Mowing is inneffective. Tillage may be used. Several biological control agents have been released.
Reproduction and Spread	Spreads by seeds and rhizomes. Produces 15,000 to 34,000 seeds per plant; seeds may remain viable for more than 50 years.
Introduced	First reported in PA in 1696. Carried to Oregon between 1840-1850.
Look Alikes	cinquefoil, buttercup
Impact	This plant is toxic to livestock such as cattle, sheep and horses, can cause severe skin lesions and hypersensitivity to sunlight.
More Info	https://wric.ucdavis.edu/information/natural%20areas/wr_H/Hypericum_perforatum.pdf https://fieldguide.mt.gov/speciesDetail.aspx?elcode=PDCLU031A0#:~:text=It%20has%20been%20introduced%20into (Campbell%20and%20Delfosse%201984).