An herbaceous perennial with a straight or sometimes zigzag stem, lacking hairs or with very few hairs. Flower clusters subtended by 1 or 2 leaves similar to the rest of the leaves. Petals 3; blue, rose, purple, lavender, or rarely white; size of petals varies; flowers triangular, about ¾–1½ inches across. Stamens bearded and fluffy. Blooms May-July. Leaves about 12 inches long; narrow, folded lengthwise; bluish green, clasping stems in a thick node.
Similar species: There are 8 species of spiderworts in the Missouri flora, plus several documented hybrids that display characteristics of more than one species. Smooth spiderwort hybridizes with nearly all of them, and it is the commonest and most widely distributed of Missouri's spiderworts.