Aug. 23, 2019

Swink's St. John's-wort, Hypericum swinkianum

Kudos to Gerould Wilhelm and Laura Rericha. They can see what no one else did. In 2016 they revealed it to the rest of us in The Michigan Botanist. A new species of St.John's-wort. Before then we would have called this shrub Kalm's St. John-wort. Swink's has larger leaves, more flowers in it's bunches, and larger sepals. It grows in sandy prairies, typically among tall grasses and other prairie dwellers. Kalm's likes damper calcareous ground, often on shores. So far Swink's has been reported from northen Illinois, Indiana, and three Michigan Counties. This one in Emmet County is the third. Wilderness State Park, 8/11/19. Floyd Swink (1921-2000) was a Chicago area botanist.

Comments

27.08.2019 12:46

Denise Gehring

Bob:
We may have found a Swink's St. Johnswort in the Oak Openings! We first thought it might be H. lobocarpum. Next step is to compare the measurements in the Michigan Botanist.