Senna alata Seeds | Candle Bush
LATIN NAME: Senna alata
COMMON NAME: Candle Bush
Plant Profile
Senna alata is a rangy tropical shrub with yellow flowers in erect, candle-like spikes and long, winged pods that look like a row of candles on a stand. The leaves are pinnate with leathery leaflets, and the plant grows to three metres in a season. It is native to the moist tropics of the Americas and is now widespread as a weed in the tropics of both hemispheres.
The species is grown for its flowers and for its reputation as a treatment for ringworm, which is why it is called the ringworm shrub. It is a short-lived perennial, often grown as an annual where frost occurs, and it seeds freely on disturbed ground.
Science & Biotechnology
The leaf contains chrysophanol and related anthraquinones, which are antifungal and laxative, and the yellow powder on the leaf surface is the active part. Extracts have shown activity against dermatophytes in vitro, which supports the traditional use on ringworm, though the same anthraquinones make an internal dose a purgative.
The plant is also a legume, with the typical pea flower reduced to five yellow petals, and the pod is winged along the seams. It grows fast and fixes nitrogen, and it is used as a green manure and as a cover crop in the tropics, where it suppresses weeds and adds organic matter. The winged pod is also the reason the plant is easy to identify in a market, where the dried pod is sold alongside the leaf.
Uses & Benefits
The crushed leaf is applied to ringworm and to other skin infections, usually as a paste or as a wash, and the leaf is also used in a bath for eczema. The pod and the leaf are used as a laxative in traditional practice, though the dose is difficult to control.
The plant is grown as an ornamental for the candle-like flowers, and it is used in tropical gardens as a background shrub. It is also planted as a green manure and as a nurse crop, and the leaf is used for mulching. In West Africa the leaf is also used in a steam bath for fever, and the root is chewed for toothache.
Growing from Seed
The seed coat is hard, so scarify it with hot water and sow at 25 to 30 degrees. Germination is in one to three weeks, and the plant grows fast enough to flower in its first season. It self-sows readily.
The plant wants full sun and a moist, well-drained soil, and it tolerates poor ground. It is tender below about two degrees, so it is grown as an annual in a temperate climate. Cut it back after flowering if self-sowing is not wanted, and wear gloves when handling it, since the leaf powder can irritate the skin.
Our Take
A yellow candle of a shrub with a real antifungal history, and one that will seed itself into every corner if allowed.
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