Triodanis perfoliata, the clasping Venus' looking-glass or clasping bellflower, is a flowering plant belonging to the family Campanulaceae. It is an annual herb native to North and South America, the natural range extending from Canada to Argentina.
Wheel-shaped, blue-violet flowers set singly in the axils of leaves that clasp the stem.
This plant also occurs in Mexico. The flowers in the lower leaf axils do not open but nonetheless produce seeds. The genus name, from the Greek treis (three) and odous (tooth), alludes to the three lobes of the calyx in many of the non-opening flowers. This distinctive annual can appear in any open spot, even in cultivated flower gardens. It is sometimes placed in the genus Specularia.
Native Habitat: Ditches, Ravines, Depressions, Hillsides, Slopes, Woodlands' edge, Opening, Prairie, Plains, Meadows, Pastures, Savannas