St. John's-worts are leafy herbs or shrubs, usually with yellow or orange flowers in branched clusters. The family was formerly named Hypericaceae. The flowers are radially symmetrical with 5 separate sepals and 5 separate petals. There are numerous stamens, usually united into several clusters by the bases of the stalks. All these parts are attached at the base of the ovary. The leaves are simple, opposite or whorled, with numerous, often black or translucent dots. The fruit is usually a capsule, sometimes a berry. There are 8 genera and about 400 species worldwide, widely distributed but most abundant in tropical and subtropical regions. Only 1 genus in our area. Two compounds present in these plants (hypericin and pseudohypericin) have been found to be potent anti-viral agents with no serious side effects, so these plants are now being studied for use in the treatment of Aids.
Guide to Identify Presented Species of the St. John's-wort Family
NATIVE PLANTS WITH BROAD LEAVES AND SEPALS
Hypericum scouleri Scouler's St. Johnswort Stems 10-80 cm tall. Moist, open slopes and ledges, foothills to alpine.
Flowers bright yellow, 2 cm wide, petals edged with small black dots or teeth.
Leaves opposite, broadly egg-shaped, 1-3 cm long, black-dotted along edges.
Alphabetical listing with links to presented species of the St. John's-wort family: