louisianica (Mill.) Thell. 1, upper part of plant showing
leaves and flowers; 2, seed pod. Annual, reproducing by seeds.
Often possessing a pronounced odor. Stems thick, soft, widely branching,
producing a bushy plant up to 3 feet (0.9 m) high and 4 feet (1.2 m) across.
Leaves opposite, or the upper ones alternate, simple, rounded or
kidney shaped, up to 12 inches (30 cm) across in well-developed plants,
densely covered with glandular hairs giving the plant a "clammy" feel.
Flowers dull white or yellow, with purplish spots, petals united
into an irregular tube, 1 to 2 inches (2.5-5 cm) across. Seed pod
woody at maturity, consisting of a rough-surfaced body about 2 inches (5
cm) long, with 2 up curved spines, 3 to 5 inches (7.5-12 cm) long, projecting
from one end. Seeds numerous, egg-shaped, 1/4 inch (6 mm) long,
dull gray or silvery gray and conspicuously wrinkled. Found in dry
open prairies and pastures; more abundant in western part of the range.
Sometimes cultivated as an ornamental. Seldom an aggressive weed, but the
seed pods show up in baled hay.