ST. JOHNSWORT, Hypericum perforatum L. 1, plant in flower; 2, portion of stem with leaves; 3, flower and buds; 4, stamens and ovaries; 5, seed. Perennial, reproducing by seeds and rootstocks. Root system branched and extending to considerable depth. Shallow, short rootstocks extend out several inches from crown. Stems smooth, branched, erect, somewhat 2 edged, 1 to 2 feet (30 to 60 cm) tall, woody at base. Leaves opposite, elliptic to oblong, covered with small clear dots. Flowers about 3/4 inch (1.9 cm) in diameter, 5-petaled, orange-yellow with occasional black dots along edges of petals. Seed pods rounded, pointed, with 3 parts and many seeds. Seeds about 1/16 inch (1.5 mm) long, cylindrical, blackish, shiny with a rough, pitted, resinous surface. Found in pastures, meadows, rangelands and along roadsides. Not relished by grazing animals; may cause skin irritation and loss of condition in livestock, especially white animals. Also commonly known as Klamath weed.