Securidaca longipedunculata Seeds | Violet Tree

Violet tree in flower with pink-violet sprays above sandy savanna soil — Violet Tree (*Securidaca longipedunculata*): Polygalaceae, savanna woodland across tropical and southern Africa.

LATIN NAME: Securidaca longipedunculata

COMMON NAME: Violet Tree

Plant Profile

Violet tree is a shrub or small tree of the African savanna, growing three to eight metres on sandy soils from Senegal east to Somalia and south to Natal. It has a slender, grey-barked trunk, a sparse crown of oval leaves and, in the dry season, long-stalked sprays of violet-pink flowers that give the tree its name. The flowers are followed by single-seeded, winged fruits that spin away on the wind and collect in drifts along tracks. The root is thick, pale and deeply buried, and it smells of wintergreen when cut. That root is the reason the plant is harvested across a continent, and the reason it is disappearing from places where it was once common.

Science & Biotechnology

The wintergreen smell comes from methyl salicylate, which is present in the root bark at concentrations high enough to be commercially interesting, alongside saponins of the polygalic acid type and a small amount of the xanthone compounds found across Polygalaceae. Methyl salicylate is the same compound that gives wintergreen oil its use as a counter-irritant, and it explains both the traditional rubs made from this root and the poisonings that follow from taking it internally. The saponins are haemolytic in vitro and are probably a defence against soil fungi and insects rather than a medicine. Taxonomic work places Securidaca among the winged-fruited genera of the family, and the fruit’s single violet wing is a reliable field character. Populations are slow-growing and fire-sensitive, and root harvesting kills the plant outright.

Uses & Benefits

The root bark is sold across West and southern Africa as a male tonic and aphrodisiac, usually as a decoction or a maceration in alcohol, and it is also used for coughs, for chest pain and as a rub for rheumatism. The trade is large and largely informal, and it has driven local extinction in parts of Nigeria and South Africa. In the garden the tree is grown for its violet flowers and its light, open habit, and it makes a good specimen for a dry, sandy site in a frost-free climate. It fixes nothing and needs no feeding. The wood is hard and used for small implements, and the fruit is decorative in dried arrangements. Anyone using the root should know that the margin between dose and poison is narrow.

Growing from Seed

Sow the winged fruit fresh, without removing the wing, in a gritty mix of sand, loam and compost. Press each one flat into the surface and cover with five millimetres of grit. Keep at twenty-five to thirty degrees; germination is slow and uneven, often spread over two months. The seedling develops a long taproot quickly, so use a deep tube and do not disturb it. Grow on in full sun with sharp drainage and little water, since damping off is the main risk. Plant out once the stem is pencil-thick, in sandy soil, and water only through the first dry season. The tree is slow to flower, often taking five or six years from seed.

Our Take

A savanna tree with violet flowers and a root worth more than the tree. Grow it for the flowers, and leave the root alone.

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