Introduced from Europe as a garden plant, and now found throughout the United States and southern Canada, often as an escape along roadsides or in disturbed lots.
A perennial that reproduces from seeds. Foliage will die back in colder climates in the winter, with regrowth from the roots and from surviving stems. It has a very rapid growth and will form large, bushy plants that may crowd out more desirable vegetation. The plant is slightly toxic but is rarely fed upon by livestock.
Mature plants are upright and extensively branched, with numerous stems that will grow to 3 feet in height. The stems are thick and strong, and the nodes are noticeably swollen. Leaves are opposite, lance-shaped to around 3 inches long, and they have 3 distinct veins running from the base to the tip. Leaf edges are slightly curled or wavy. The flowers occur in groups of up to a dozen or more at the ends of the stems, with white to pinkish petals that are notched at the tip. The five petals are fused to form a long, cylindrical tube that is within the green to violet-red calyx.
Characteristicts Important to Control:
Physical removal may be effective, although underground parts can be capable of re-growth. A non-selective or selective systemic herbicide will control the plant where necessary.