Kalm’s St. John’s-wort

Hypericum kalmianum

Common Name: Kalm’s St. John’s-wort

  • Bright yellow, showy flowers.
  • A shrub with many branches, that grows up to 39 inches tall.
  • Flowers from June to August.
  • Part of the family of St. John’s-wort that has long been used to treat depression, with mixed results.

Native or Invasive: Native shrub

Characteristics: A low, many-branched shrub with bright yellow flowers and conspicuously showy stamens (male parts) in the middle of the flowers. The leaves are opposite, are blue-green in color and are firm. It is found along the shores of Lakes Erie, Huron and Michigan and some inland locations and grows sparsely in Quebec.

Habitat: Grows on calcareous (alkaline) shores and sand dunes. It is also found inland in fens and moist meadows.

Fun Fact: St. John’s-wort has long been used to treat mild depression. Evidence on its effectiveness, however, has been inconclusive.

Ethnobotanical Uses: Different varieties of St. John’s-wort have been used to cure fevers, intestinal problems, nosebleeds, snakebites and sores and also to give strength to infants and children.

Adapted from Guide to Great Lakes Coastal Plants, by Ellen Elliott Weatherbee, University of Michigan Press.