Senna didymobotyra

Flowers
Common Name: popcorn cassia 
Type: Broadleaf evergreen
Family: Fabaceae
Native Range: Southern India, Sri Lanka, Malesia, tropical Africa
Zone: 9 to 11
Height: 3.00 to 16.00 feet
Spread: 3.00 to 16.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Yellow
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Annual
Flower: Showy
Leaf: Fragrant

Culture

Best grown in evenly moist, rich, well-draining soil in full sun. Thrives in hot and humid climates and will grow and flower vigorously when provided adequate moisture and fertilizer. Propagate with seed. Seeds require pre-treatment for good germination. Scarification with near boiling water or mechanical abrasion are two recommended methods. Best germination with warm soil temperatures of between 70-80°F. Hardy in Zones 9-11. Tolerant of light frost. Commonly grown as an annual in colder climates.

Noteworthy Characteristics

Senna didymobotrya, commonly called popcorn cassia or peanut butter cassia, is an evergreen shrub or small tree native to tropical eastern and central Africa where it typically grows in riparian areas along forest edges, in savannahs, evergreen bushland and thicket, and disturbed areas such as roadsides and wasteland. This species is grown as an ornamental and medicinal plant in tropical regions around the world. It has escaped cultivation and naturalized in tropical areas around the world and is considered invasive in South Africa. Mature plants tend to take on a multi-stemmed, mounding to spreading growth habit and can reach 16' tall (rarely up to 30') with a canopy of more or less equal spread. The spirally arranged, pinnately compound leaves will reach 6-12" long and are made up of 8-16 pairs of 1-2.5" long, up to 1" wide, oval to oblanceolate leaflets. The foliage is highly fragrant with a unique odor said to resemble buttered popcorn or peanut butter. Upright, spike-like racemes of 20-30, bright yellow flowers bloom seasonally from the leaf axils of the uppermost leaves. The flowers are followed by flattened, oblong, green seed pods that mature to dark brown and will reach 3-5" long. Synonymous with Cassia didymobotrya.

The specific epithet didymobotrya comes from the Greek meaning “held in paired clusters" and refers to the flowering racemes.

The common names of this species refer to the genus Cassia, to which it previously belonged, as well as the various foods and flavors its fragrant foliage is said to resemble.

Problems

No major pest or disease problems of note.

Uses

Accent for tropical gardens, annual displays, or back of mixed borders. Suitable for large containers. This plant has a number of traditional uses including as a fish poison, dye plant, and green manure. It has also been used traditionally to treat a wide range of medical ailments, however all parts of the plant are poisonous and its use as an herbal are not recommended.