Kalm's St. Johnswort

Hypericum kalmianum

Kalm's St. Johnswort is very similar to Shrubby St. Johnswort in general appearance, a shrub that is quite showy when in bloom with its clusters of bright yellow flowers.

This species is native to the shores of the Great Lakes and the St. Lawrence River. It can be distinguished from Shrubby St. Johnswort, which has a wider range, by the five fused central styles of each flower; Shrubby St. Johnswort has three fused styles.

Kalm's St. Johnswort is frequently encountered in open wild areas of Jackson Park.


1-4 feet, sun - partial sun.


Summer (June-August).

The five fused central styles are clearly visible in this photo.

2 July 2021.

Kalm's St. Johnswort, 2 July 2021.