About Hypericum kalmianum L.
Hypericum kalmianum L. (Kalm's St. Johnswort) is a slender shrub that reaches 20 to 60 cm (7.9 to 23.6 in) in height. It has whitish, papery bark, and ascending four-edged branches that produce two-edged branchlets. Its crowded, bluish-green leaves are linear to oblanceolate, and measure 3 to 4.5 cm (1.2 to 1.8 in) long. Between one and ten yellow flowers grow in terminal, open corymbs, and each individual flower is 2 to 3.5 cm (0.8 to 1.4 in) wide. Its leaf-like sepals are oblong and 5 to 15 mm (0.2 to 0.6 in) long. The plant's ovoid capsules most commonly have five carpels and styles, but may occasionally have three, four, or six instead. Capsules are 7 to 10 mm (0.3 to 0.4 in) long and 4 to 7 mm (0.2 to 0.3 in) thick. This species flowers between June and August. Kalm's St. Johnswort is primarily distributed around the Great Lakes in the Canadian provinces of Ontario and Quebec, and the U.S. states of Illinois, Indiana, Michigan, New York, Ohio, and Wisconsin. In the Chicago Region, it is a highly conservative species that grows near Lake Michigan in calcareous sand prairies and marly pannés; it is rarely found inland, but can occur in prairie fens and mesic prairies. It is listed as endangered in Illinois and threatened in Ohio.
