Common name:Stinking weed
Scientific name:Senna occidentalis
Alternative common names:
A smallish shrub or erect herb growing 50cm-2m high. The vivid green leaves occur as leaflets usually in 4-5 opposite pairs, which are lance-shaped to elliptical and 40-100mm long. Pale yellow flowers in 2-4 flowered axillary racemes during the summer months. It is competitive and poisonous and competes against indigenous species. Crushed parts have an unpleasant smell lending it the common name of stinking weed.
Where does this species come from?Tropical America.
What is its invasive status in South Africa?NEMBA Category 1b.
Where in South Africa is it a problem?Eastern parts, including Limpopo, Mpumalanga and KwaZulu-Natal Provinces.
How does it spread?Seed dispersal – produces prolific seeds in pods.
Why is it a problem?It is competitive and poisonous and competes against indigenous species for similar resources, such as sun, nutrients, water etc. It invades roadsides and riverbanks in savanna and grassland as well as waste land and disturbed fields.
What does it look like?Leaves: Leaflets usually in 4-5 opposite pairs, lance-shaped to elliptical and 40-100mm long. The leaf petioles have a conspicuous gland. Flowers: Pale yellow flowers in 2-4 flowered axillary racemes. Flowers during the summer months (December to March). Fruit/seeds: Green pods maturing to brown with thicker margins 80-100mm long.
Does the plant have any uses?Ornamental shrub.