Caesalpinia bonduc

grey nickernut


Caesalpinia bonduc

(L.) Roxb. 1832

pronounced: ses-al-PIN-ee-uh BON-duck

(Fabaceae — the pea family)

subfamily: Caesalpinioideae - the cassia subfamily


common name: grey nickernut

native 4Caesalpinia was named for Andreas Caesalpini (1519–1603), Italian botanist, physician and Professor of Medicine at Pisa. Bonduc is the Arabic name for the hazel-nut. The word ‘nicker’ derives from the Dutch word knikker, meaning ‘a baked clay marble’.

This is a large straggling, very thorny shrub or scrambler, armed with hooks and straight hard yellow prickles.

The leaves are bipinnate, large, the stipules leaf-like, with 7 pairs of pinnae. There are 3–8 pairs of leaflets with 1 or 2 small recurved prickles between them on the underside.

The small flowers are yellow, in dense long pedunculate racemes produced in the leaf axils.

The fruits are inflated pods, covered with wiry prickles, with 1 – 2 seeds per pod, oblong or globular, hard and grey with a smooth shiny surface. It is widely distributed throughout tropical regions of the world, as the seeds can retain their viability for a number of years, even in sea water.

The plant is found in the coastal scrubs of northern Australia and adjacent islands, including Lord Howe Island. This last is now the only part of NSW where the plant is found, although there were several NSW locations in the 1890s. It also seems that the number of plants on Lord Howe Island is decreasing. Invasion of its habitat by weeds, especially Buffalo grass and Kikuyu grass, that are forming dense swards beneath the Caesalpinia bonduc plants, seems to be limiting the recruitment of its seedlings. The plant has now been declared an endangered species in NSW. Along beaches of the West Indies, the spiny shrubs often form impenetrable thickets, and the ground is littered with seeds resembling shiny grey birds’ eggs. When washed into the sea by high tides, these seeds are often carried by the Gulf Stream and the North Atlantic Current to beaches of northern Europe. Islanders in the Hebrides off the western coast of Scotland wore nickernut seeds as an amulet to ward off evil spirits. Known in the Hebrides as the white Indian nut, the seeds were believed to have other magical powers, and were also a cure for dysentery when the powdered embryo was taken with boiled milk. The seeds contain bonducin, a white bitter glycoside sometimes referred to as ‘poor man’s quinine’.

The plant is a food source for the larvae of the Speckled Line Blue Catopyrops florinda.

In the Caribbean, nickernuts were ground with roasted senna seeds to make a medicinal coffee or tea. Numerous naturopathic remedies have been attributed to the soothing tea, including colds and stomach disorders. In the Caribbean, the seeds are collected and strung into bracelets and necklaces, often mixed with the seeds of other plants. In Ecuador, drilled nickernuts are sold by street vendors along with a variety of other seeds and herbs used for folk remedies. They are strung with the beautiful half-red, half-black seeds of the necklace tree, Ormosia sp., and worn as bracelets to ward off the devil. Polished nickernuts turn up in necklaces from India, Nepal, Indonesia and French Polynesia. In Indian Ayurveda medicine, the seeds, leaves and root bark are used to treat an enormous range of conditions and illnesses, including arthritis, indigestion, liver ailments, worm infestation, diabetes, skin ailments, fever, piles, diarrhoea, dysentery, coughs and colds, and also used as a contraceptive.

Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.


Photographs taken at Arcadia 2010, 2011
Page last updated 25th October 2018