Description

This plant is an annual, biennial, or short-lived perennial (usually an annual or biennial in Illinois). It is about 5-14' tall, erect to sprawling, and sparingly to abundantly branched. The stems are light green to purplish green, glabrous, and angular. Alternate leaves occur along these stems; their blades are ¾-1½' long (not including their petioles) and variously shaped. Lower leaf  blades are cordate-ovate, while middle to upper leaf blades are lanceolate or oblong-lanceolate. All leaf blades are medium green, glabrous (or nearly so), and sparsely crenate-dentate along their margins. Sometimes a few scattered hairs occur along the midveins on the lower sides of the blades. The petioles are about ¼-½' long and relatively broad. At the base of each leaf petiole, there is a pair of leafy stipules that clasp the stem. These stipules are about ¾-1½' long and deeply pinnatifid. Because of their large size, the stipules are often difficult to distinguish from the leaf blades. Occasionally, individual flowers are produced from the leaf axils on long ascending pedicels with nodding tips. The pedicels are light green to purplish green and glabrous. Each flower is ¾-1¼' across, consisting of 5 widely spreading petals, 5 sepals, a pistil with a swollen stigma, and 5 inserted stamens. The typical flower has violet or purple upper petals, white lateral petals, and a yellow lower petal, but other color variations are possible. Several purple veins originate from the throat of the flower. The lateral petals have small tufts of white hair at their bases, while the lower petal terminates in a nectar spur that is short and blunt. The sepals are medium green or purplish green, glabrous, lanceolate, and about ¼' long; they are much shorter than the petals. The blooming period occurs from late spring to mid-summer for about 1-2 months; sometimes the flowers will bloom later in the summer or autumn. The flowers are usually fragrant. Fertile flowers are replaced by seed capsules about ½' long that are ovoid-oblongoid in shape and glabrous. At maturity, each seed capsule divides into 3 segments, ejecting the seeds. The root system is shallow and fibrous.