Senna alata is a deciduous shrub or small tree with horizontal branches; it can grow up to 8 metres tall, but is more commonly around 2 metres.
The plant is highly valued in many areas of the tropics for its medicinal virtues. It is commonly gathered from the wild, mainly for medicinal use but also as a food and source of materials. It is often cultivated for medicinal purposes, and also as an ornamental plant in tropical to warm temperate areas.

Known Hazards

The plant can become a weed in pastures; it is not eaten by livestock and is reported to be poisonous, especially for goats. The bark is used as fish poison.

Habitat

Found in many habitats, preferring disturbed, rather open vegetation such as roadsides, river banks, rain forest edges, lake shores, pond and ditch margins, open forest, orchards and around villages, at elevations up to 1,400 metres, occ 2,100 metres.

Cultivation Status

Cultivated, Ornamental, Wild

Cultivation Details

A plant of moisture areas in the tropics, where it is usually found at lower elevations but occasionally as high as 2,100 metres. It is reported to tolerate a mean annual rainfall of 600 - 4,300mm and average yearly temperatures of 15 - 30°c. It is very susceptible to frost damage.
Prefers a moist but well-drained soil in a sunny position. It grows well on both heavy and sandy, acid to slightly alkaline, well-drained soils. This species occasionally escapes from cultivation to become naturalized, but it does not readily spread. In many countries, including most countries of tropical Africa, it has become naturalized and is often considered a weed. It is sometimes becoming a troublesome weed in pastures since the livestock will not eat it and a rapid spread can reduce the area available for grazing. A fast-growing, but short-lived plant. Plants can flower and produce fruit all year round. Very tolerant of pruning, it can be cut back severely on a regular basis in order to maintain its shape. Although many species within the family Fabaceae have a symbiotic relationship with soil bacteria, this species is said to be devoid of such a relationship and therefore does not fix atmospheric nitrogen.

Edible Uses

Young leaves - cooked. Toasted leaves are sometimes used as a coffee substitute. Young pods - cooked and eaten as a vegetable. Only used in small amounts.

Medicinal

Senna alata, known as Ringworm Bush or Candle Bush, is widely used as a traditional medicine, particularly valued for its laxative effect and its effective treatment of several skin conditions, including ringworm and scabies. Research has tended to confirm the validity of these traditional treatments. A number of anthraquinone derivatives have been isolated from the leaves, such as aloe-emodin, chrysophanol, isochrysophanol and rhein, as well as the alkaloid tyramine and the common steroid beta-sitosterol. Crude leaf extracts have shown antibacterial activity against a range of bacteria (such as Dermatophilus congolensis, which causes a serious skin condition in cattle), antifungal properties (such as against Pityriasis versicolor in humans), and also antitumour activity. The bark contains tannins. The petals contain anthraquinones, glycosides, steroids, tannins and volatile oil. Extracts of the petals have bactericidal activity against gram-positive bacteria but not against gram-negative bacteria. The plant is laxative, antibacterial, antitumor, anti-inflammatory, diuretic, analgesic, vulnerable, weakly antifungal, hypoglycaemic, and antispasmodic. The leaves are laxative. They are taken internally as a remedy for constipation and to purify the blood. The leaves are decocted, with or without Tripogandra serrulata and Persea americana, as a treatment for biliousness and hypertension. The leaves are widely used in treating skin diseases. They can be applied as a tincture; as a poultice; powdered, then mixed with oil as an ointment; or the sap can be spread over the affected area - they form an effective treatment for skin blemishes, scabies, ringworm and other fungal skin infections. The leaves can be harvested at any time of the year, but are seen as being at their best in the month or two prior to the plant flowering. The bark is used to treat skin diseases, diarrhoea, worms, parasitic skin diseases, scabies and eczema. The root is laxative. An infusion is used in the treatment of diarrhoea, tympanites, uterus problems and filaria worm expulsion. The root is applied externally to treat sores and skin fungi. The flowers are used as a laxative and vermifuge. An infusion is used for remedying spleen conditions. A decoction combined with Zingiber officinale, is used as a treatment for grippe and as an abortifacient. They are decocted with coconut milk for use as a laxative. The leaves, flowers and fruit are mixed in an infusion to treat stomach problems. The seed is laxative and anthelmintic. It is cooked and used as a remedy for intestinal worms. The leaf contains the purgative anthraquinone, and also shows some antimicrobial activity. The stem contains chrysophanol, emodin, rhein and aloe emodin. The leaf and fruit contain purgative anthracene derivatives of aloe emodin and rhein.

Agroforestry Uses

None Recorded

Other Uses

The plant has insecticidal properties. The bark is a source of tannins. It is sometimes used as a colouring in tattooing.

Propagation

Seed - requires pre-treatment to soften the hard seedcoat and allow the ingress of water. This can be done by soaking the seed in a small amount of nearly boiling water (which cools down quickly and does not cook the seed) and then soaking the seed for 12 - 24 hours in warm water. Alternatively, a small area of the seed coat can be abraded, being careful not to damage the embryo. Cuttings