FIELD GUIDE TO SHRUBS

St. John’s Wort (Kalm Hypericum)
Hypericum kalmianum

Family: Hypericaceae

Preferred Habitat: Rocky to sandy soils, ranging from relatively dry open woods to moist lakeshore areas

Range: From Great Lakes region, Quebec and Ontario to Michigan and Illinois

Height: up to 1 meter (3 feet)

Leaves: simple, opposite and linear-oblong with a prominent and impressed midrib, the leaves maintain a dark bluish green color all season into late fall, a white waxy bloom can be found on the underside of the leaves

Flowers: bright yellow and 3 cm in diameter, occur in 3-flowered clusters produced throughout July, flowers consist of 5 yellow petals surrounding a mass of bright yellow stamens

Fruit: the small, 2 cm fruits are 3-5 celled ovate reddish brown capsules persisting from late summer through the winter

Location spotted: Arnold Arboretum of Harvard University

Extra information: German and American researchers report the herb to be effective in treating depression