Pronounced (approximate): hy-PAIR-ih-kum kal-mee-AY-num
Golden five-petaled flowers have a dense tuft of stamens.
Kalm’s St. John’s-wort (Hypericum kalmianum): flowers and plant details. Tap the photo to open the gallery.
Family Hypericaceae
Life cycle Small woody shrub
Blooms July–August
Height 1–2 feet
Habitat Calcareous shores, moist sandy ground, dunes, and rocky openings
Common names: Kalm’s St. John’s-wort · Kalm's St. John's Wort · Kalm's Saint Johnswort
Bloom timing and height vary with location. See the regional range below.
Explore reported observations. Sightings are not a complete range map.
Calcareous shores, moist sandy ground, dunes, and rocky openings. Flowering season: july–august.
The narrow leaves and small flower clusters are useful when comparing other shrubby Hypericum species.
Golden five-petaled flowers have a dense tuft of stamens.
Narrow leaves occur in opposite pairs.
Woody branching stems distinguish it from herbaceous St. John’s-worts.
Calcareous shores, moist sandy ground, dunes, and rocky openings.
14 field photographs. Select a photograph to enlarge it; use Load more photos to see the rest.
Native mainly around the Great Lakes, from eastern Canada into the north-central and northeastern United States.
Documented U.S. state records
IL, IN, MI, MN, NY, OH, WI, DC
Documented state occurrences; native and introduced records may both be included. This is not a county-level map.
Observation maps show submitted records, not every place the plant occurs. Follow local access rules when visiting a site.
Practice recognizing Kalm’s St. John’s-wort in the flower quiz, or compare it with other plants in the guide.
Field photographs: Where’s Wildlife.