Cinnamon willow-herb, a North American native, is a member of the evening primrose family.
Identification: This species is quite variable. They have a vaguely disorganized look about them.
Plants are 1-3′ (30-91 cm) tall, erect,
sometimes branching. Stems may be square or round. Leaves may be opposite or
alternate. They attach directly to the leaf ("sessile") or by a short stem, called the
petiole. Leaves are toothed, narrow ("lanceolate"), up to 4″ (10 cm) × ½″ (1.3 cm).
Flowers are ¼″ (8.5 mm) around, with four white or pale pink petals, each petal with two lobes.
The flowers are in racemes—loose clusters—and they appear from July to August. Each
flower tops a "stem" about 2″ (6 cm) long that develops into a skinny fruit, like a straight
bean, about 1/32″ (1.3 mm) around.