Sesbania herbacea (Mill.) McVaugh

Coffee-Weed

Sesbania_herbacea_plant.jpg
STATS

Native
CC = 3
CW = -3
MOC = 15

© SRTurner

Family - Fabaceae/Faboideae

Habit - Taprooted annual forb.

Sesbania_herbacea_seedling.jpg Young plant.

© SRTurner

Stems - Erect, to 2 m, the base often somewhat swollen and spongy, glabrous, glaucous.

Sesbania_herbacea_stem.jpg Stem and nodes.

© SRTurner

Leaves - Alternate, pinnately compound, short-petiolate. Blades 8-30 cm long, with 30-70 leaflets. Leaflets 10-25 mm long, 2-6 mm wide, narrowly oblong to occasionally linear, entire, the surfaces glabrous.

Sesbania_herbacea_leaves.jpg Pressed leaves.

© DETenaglia

Sesbania_herbacea_leaflets1.jpg Leaflets adaxial.

© SRTurner

Sesbania_herbacea_leaflets2.jpg Leaflets abaxial.

© SRTurner

Inflorescence - Loose axillary clusters 2-6 cm long with 2-7 flowers, the flower stalks 5-9 mm long.

Sesbania_herbacea_inflorescence.jpg Inflorescence.

© SRTurner

Flowers - Calyx tubes 3-4 mm long, with short triangular lobes, bell shaped, glabrous, the lobes 1-2 mm long. Corollas papilionaceous, 11-15 mm long, glabrous, yellow. Stamens 10, with 9 filaments fused nearly to the tip.

Sesbania_herbacea_flower.jpg Flower.

© SRTurner

Sesbania_herbacea_calyx.jpg Calyx.

© SRTurner

Sesbania_herbacea_flower2.jpg Flower.

© SRTurner

Sesbania_herbacea_flower3.jpg Flower.

© SRTurner

Fruits - Legumes, 10-20 cm long, 3-4 mm wide, quadrangular in cross section, with 20-40 seeds, these 3-4 mm long, oblong-ellipsoid.

Sesbania_herbacea_fruits.jpg Plant in fruit.

© SRTurner

Sesbania_herbacea_fruit.jpg Fruit.

© DETenaglia

Sesbania_herbacea_seeds.jpg Seeds.

© SRTurner

Flowering - July - October.

Habitat - Bottomland forests, streambanks, oxbows, sloughs, crop fields, railroads, roadsides, open disturbed areas.

Origin - Native to North America.

Other information - In Missouri, this weedy yet attractive species has been found in three disjunct regions: in the Bootheel, near the far southwestern corner of the state, and mid-state along the major rivers. Missouri lies along the extreme northern extent of the plant's natural range, which occupies much of the southern portion of the country. The plant is readily identified by its tall stature, glabrous stems, large compound leaves, big yellow flowers, and long, drooping fruits. The leaves grow perpendicular to the stem giving the plant a distinctive appearance. Plants can grow to 3m tall or more. There is some resemblance to S. vesicaria, but that species is quite rare in Missouri and has smaller flowers and much different fruits.

The genus name Sesbania is a latinized version of the old name "Sesban" of Arabic origin. The species epithet herbacea derives from the Latin "herb(a)" meaning "grass, not woody." The taxonomy has been somewhat controversial. The plant has been used for erosion control. The seeds contain saponins and other toxic compounds which cause severe diarrhea and internal hemorrhaging.

Photographs taken off Hwy 29, Macon County, AL., 10-9-04 (DETenaglia); also Holly Ridge Conservation Area, Stoddard County, MO, 10-05-2011, Otter Slough Conservation Area, Stoddard County, MO, 8-19-2013, 9-11-2019, and 8-07-2022, and Dresser Island Conservation Area, St. Charles County, MO, 7-28-2020 (SRTurner).