Senna obtusifolia

Species Native to Missouri
Common Name: java-bean 
Type: Herbaceous perennial
Family: Fabaceae
Native Range: Eastern United States, Central America, Northern South America
Zone: 5 to 10
Height: 2.00 to 5.00 feet
Spread: 2.00 to 5.00 feet
Bloom Time: July to September
Bloom Description: Yellow
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy
Tolerate: Drought, Clay Soil

Culture

Easily grown in moderately dry to moist well-drained soils in full sun. Tolerates brief periods of drought. Tolerates rocky soils. Freely self-seeds in the landscape.

Noteworthy Characteristics

Senna obtusifolia, commonly known as sicklepod, is an often short-lived, upright to sometimes sprawling, herbaceous perennial of the pea/bean family that typically grows to 2 1/2’ tall, featuring compound-pinnate light green leaves and yellow flowers. It has a variable growth habit, occasionally appearing in some areas as a sub-shrub rising to as much as 5’ tall or as an annual. In North America, it is typically found growing on wooded slopes and ravines in the Southeastern and Midwestern U.S., but has naturalized into a variety of other areas as a weed of disturbed soils. The USDA currently defines its native U.S. territory as extending from New York to Nebraska south to Texas and Florida. It has been introduced into California and Hawaii with subsequent naturalization occurring. It is now classified as a noxious weed in the State of California. Notwithstanding its presence in North America, it also grows in the wild in Central America, South America, Asia, Africa and Oceania.

Compound leaves have 2-3 pairs of obovate leaflets with rounded tips. Each leaflet grows to 1 1/2” long and to 1” across. Foliage has an unpleasant odor. Yellow flowers (5/8” across) bloom late summer to fall (July-September) in pairs from the upper leaf axils. Each flower has five yellow to pale yellow petals and five green sepals plus 7 fertile stamens with beaked anthers. Flowers are followed by slender, 4-sided, strongly-curved, sickle-shaped pods (to 7” long and only 1/4” wide), hence the common name of sicklepod for this plant. Pods are almost round in cross-section. Pods turn brownish-green when they mature.

Senna obtusifolia has been treated under a wide range of different scientific names and common names. The Plant List currently itemizes a number of synonyms for this species including Cassia obtusifolia, Cassia tora var. obtusifolia and Diallobus tora.

Specific epithet comes from the Latin words obtusus meaning dull or blunt and folium meaning leaf in reference to leaf shape.

Common name of sicklepod is in reference to its curved, slender seed pods which are 4-6” long.

Problems

No serious insect or disease problems.

Garden Uses

Variable plant that is uncommonly grown as an ornamental in U.S. gardens. Interesting accent for cottage, wildflower, or native plant gardens.