Hypericum sphaerocarpum, the roundseed St. Johnswort[1] or barrens St. John's wort, is a species of flowering plant in the St. John's wort family.

It is native to the Eastern United States where it is primarily found in the Midwest and Mid-South as well as Ontario, Canada.

[2] Its preferred habitat is dry, calcareous glades and prairies.

[3] Hypericum sphaerocarpum is a semi-woody perennial that produces clusters of yellow flowers in the summer.

H. sphaerocarpum can be distinguished by its smaller flowers, glossy leaves, and patch-forming rhizomes.