Kallstroemia

Kallstroemia is a genus of flowering plants in the caltrop family, Zygophyllaceae. The approximately 17 species it contains are native to tropical and warm temperate regions of the Americas. The flower and fruit morphology is similar to Tribulus. The convex fruits separate into about 10 nutlets each with one seed. The genus is named after A. Kallstroem who lived in the 18th century.