Senna obtusifolia aka American Sicklepod

People call Senna obtusifolia sicklepod, coffeeweed, or java-bean. It belongs to Fabaceae, the bean family. It is native to tropical and subtropical parts of the Americas. NC State also lists the eastern and midwestern United States. People have brought it to many other regions. It grows in open woods, fields, and ground people have disturbed. It also grows beside rivers and lakes.

Its life span and shape vary with place. It may live for one year as an annual. It may also be a short-lived perennial or small shrub. Its branches grow upright or spread across the ground. Garden plants reach 2–5 feet [0.61–1.52 metres] tall and wide. Missouri Botanical Garden lists heights near 2.5 feet [0.76 metres]. Useful Tropical Plants lists heights up to 6.6 feet [2 metres]. Pale green stems have slight ridges. Leaves grow in turn along the stems, rather than in pairs. They are pinnate, with three pairs of leaflets along a stalk. Each leaflet is broad near its rounded, pointed tip. The leaves lack hairs and have pale undersides. They have a bad smell.

Yellow flowers grow in pairs at the upper leaf joints. Each has five petals and spans less than an inch. Missouri Botanical Garden lists blooms from July to September. NC State lists blooms from late summer into fall. Thin pods follow the flowers and curve like a sickle. They turn from green to brown as they ripen. The plant can pollinate itself and spreads with ease through seed.

Grow sicklepod in full sun, in soil that drains well. It suits moist to somewhat dry soil. It copes with short dry spells and hard-packed clay. It also grows in rocky ground. Useful Tropical Plants says it prefers deep sandy loam. Missouri Botanical Garden lists medium water needs. Both US garden sources list USDA zones 5–10. The yellow blooms suit cottage gardens and wildflower gardens. They also suit native plant gardens. Yet sicklepod can become a weed on farms and disturbed sites. Some states list it as a noxious weed. Missouri Botanical Garden reports no major pests or diseases.

People eat young shoots and tender leaves once prepared. NC State describes boiling the shoots twice. This method discards the water from the first boil. In Africa, people use fermented leaves as food and seasoning. People have used roasted seeds in place of coffee. Ground seeds supply cassia gum, which thickens food. Roots, leaves, and seeds have uses in traditional medicine. Plant parts yield dyes, and stems serve for mats and fences. These food uses do not mean raw seeds are safe. NC State warns that large amounts can poison people. Signs include diarrhea, tremors, and dark brown urine. Eating many older leaves can also cause diarrhea.