What a lovely color. This is Venus’ Looking Glass (Triodanis perfoliata), in the Bellflower family (Campanulaceae). Its leaves clasp the stem, giving it another common name, Clasping Bellflower.

Native to North and South America, ranging from Canada to Argentina. Pollinators attracted to Venus’ Looking Glass are small bees, and small butterflies and skippers.

This annual herbaceous plant grows unbranched between 4 and 10 inches tall. Blooms appear in late spring into early summer. Very small seeds are wind dispersed. Much to my delight that wind has brought a couple of those seeds into the vegetable garden and now I’ve got purple blooms along with the tomatoes, lettuce, and peppers.