This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Biennial. Propagates by seeds. Time of bloom: June to September. Seed-time: July to October. Range: Nova Scotia, Ontario, New England, and the Middle States. Habitat: Grain fields, meadows, roadsides, and waste places.
Stems one to two feet tall, erect, clammy-hairy particularly just below the swollen joints, branching near the top. Basal leaves oblong, pointed, long-petioled; stem-leaves sessile or the lower ones with short petioles, ovate, acute. Flowers in cymose clusters, each nearly an inch broad, dioecious, without fragrance, and open in the daytime; petals deeply notched, red, or often nearly white; calyx on staminate plants tubular but on fertile plants becoming nearly globular, the teeth short and acute. Capsules large, one-celled, many-seeded. (Fig. 96.) Means of control the same as for White Cockle.
Fig. 96.- Red Campion (Lychnis dioica). X 1/4.