This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Annual or biennial. Propagates by seeds.
Time of bloom: June to August.
Seed-time: August to September.
Range: New Brunswick to South Dakota, southward to Georgia, Arkansas, and Kansas. Habitat: Moist, rich soil; woodland borders, thickets along streams, damp grasslands.
One of the most stately and handsome of our wild flowers, a weed only when it enters the meadows and pastures. Stem erect, slender, finely grooved, sometimes attaining six feet in height but oftener two or three feet tall, usually simple but sometimes with slender ascending branches. Leaves large, thin, dark green, the lower ones ovate with rounded or abruptly narrowed bases and petioles nearly half as long as the blades, the upper ones oblong to lance-shaped, short-petioled or sessile; all toothed and pointed, rather drooping on the stalk. Flowers in terminal racemes one to two feet long, interrupted and leafy; corolla pale blue or almost white, about an inch broad, the five deep lobes spread nearly wheel-shaped, their edges slightly wavy; style very much exserted and declined, with its three-cleft tip curved upward. Capsule three-celled, slenderly top-shaped, smooth, erect, sessile, opening by valves near the summit.
Close cutting before the earliest flowers mature.