Sesbania (Coffeeweed)

Sesbania herbacea (formerly S. exaltata)

sesbania_12-30-13.jpg

Photo of sesbania flowers and foliage
John D. Byrd, Mississippi State University, Bugwood.org
Poisonous
Invasive
Other Common Name
Bequilla; Coffee-Weed; Hemp Sesbania; Bigpod Sesbania; Colorado River hemp
Family

Fabaceae (beans)

Description

Sesbania is an erect annual herb of the legume family that typically grows to a height of 3–10 feet. The base can become woody with age. Its rather large leaves are 4–12 inches long with 20–70 leaflets per leaf. Flowers are 1/2 to 3/4 inch long, yellowish, and strongly speckled with purplish brown.

It has slender, four-sided pods, about 6–8 inches long and 1/8 to 3/16 inch wide, often curved, often tipped with a thin "beak." The seeds are small and numerous, about 1/8 to 3/16 inch long and 1/16 inch wide. The seeds are more or less orange on their attachment side, with the other surface possessing a more or less olive-green background, speckled or blotched with black.

Size

Height: 3–10 feet.

Habitat and conservation

Sesbania prefers wet, highly disturbed habitats and sandy sites. It occurs in low sandy fields, sand bars of streams, alluvial ground along sloughs and borders of oxbow lakes, and along roadsides, railroads, in disturbed urban sites, and agricultural areas. It may become a troublesome exotic species in wetland communities that are managed for waterfowl.

image of Sesbania Bequilla Coffee-Weed Hemp Sesbania distribution map
Distribution in Missouri

Potentially statewide. Most common in the Mississippi Lowlands of southeastern Missouri, but scattered in southern and central portions.

Life cycle

Optimum germination occurs late in the growing season when mudflats are exposed during periods of elevated temperatures.

Human connections

Natural events such as flooding as well as human activities create soil disturbances that allow this plant to become established. Help control this weed. Sesbania contains saponin, which is toxic to mammals (including livestock and people). The seeds are especially toxic and can kill cattle.

Ecosystem connections

Invasive plants cause problems by outcompeting others. Like many other weeds, sesbania thrives in disturbed habitats and has trouble colonizing high-quality natural communities. As a legume, sesbania's root system adds nitrogen to the soil and enrichens it to some extent.