Hypericum kalmianum
Kalm's St. John's wort
Family HypericaceaeAlso called Kalm's St. Johnswort
About
Kalm's St. John's wort is a slender shrub of the Great Lakes shores with papery bark, bluish-green leaves and yellow summer flowers.
Care at a glance
- Pet safety
- Not recorded. We have no source on whether this plant is safe for cats, dogs or other pets — that is not the same as safe. Keep it out of reach until you have checked.
- People
- Not recorded.
- Mature size
- 20–60 cm tall.
Field notes
Morphology
Grows 20–60 cm tall with whitish papery bark and four-edged branches. Crowded linear leaves are 3–4.5 cm long. One to ten flowers 2–3.5 cm wide open June to August, followed by usually five-parted capsules.
Distribution & habitat
Around the Great Lakes in Ontario, Quebec, Illinois, Indiana, Michigan, New York, Ohio and Wisconsin, in calcareous sand prairies, pannes and prairie fens.
History & etymology
Named after Swedish botanist Pehr Kalm. H. swinkianum, described in 2016, was split from it; that species has broader leaves and prefers acidic habitats.
Conservation
Endangered in Illinois and threatened in Ohio.
Habitat
- Altitude
- Not recorded
- Altitude class
- —
- Native to
- Canada, United States
Cultivation
- Difficulty
- Not recorded
Text adapted from Wikipedia, CC BY-SA 4.0.
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