The genus Ecballium, which contains a single species, is endemic to the Mediterranean region of Europe. This low-growing, perennial herb with rough, hairy leaves has no persistent woody stem, so creates an untidy, ground cover in the garden. Individual plants usually produce a mixture of male and female flowers, with pale yellow petals, from June to August. Females flowers develop into ovoid, gherkin-like, bristly, green berries in late September.
The generic name Ecballium, derived from the Greek verb ‘to expel, throw or cast out’, is a reference to the behaviour of the mature fruits. Once fully ripe, seeds explode from the ruptured fruit – a firecracker of the natural world!
As the fruit develops it expands but eventually its walls stops growing, although liquid continues to enter the fruit. The fruit swells until the internal pressure it great enough to rupture the point of natural weakness, at the place where the stalk enters the fruit. Alternatively, the mature fruit is released by environmental disturbances, such as Ecballium stems being knocked by wind or animals. The fruit is released at high speed – like a water-filled balloon from the end of a tap – squirting and casting out mucilaginous juices filled with seeds. This hydraulic mechanism of dispersal, which is capable of projecting seeds several metres beyond the parental plant, is well adapted to facilitate colonisation of new areas in its native habitat.
Ecballium has been used in medicine for millennia, with a description in Dioscorides’ De Materia Medica being an early example of its use in pharmacopoeia. The species’ strong purgative properties are apparently because of the presence of elaterin.
This curious plant did not go unnoticed during the Italian Renaissance, where flowers and fruit forms were often used in art as visual or hidden messages. Within Sandro Botticelli’s famous painting Venus and Mars (c.1485), the illustration of a fruit under the hand of a satyr has created much discussion about the identity of the fruit and why it was incorporated in the painting. The fruit was always considered to be the thorn apple (Datura stramonium). However, this species is native to the Americas, and was not introduced into Europe until the mid-eighteenth century. Recently, an alternative identification for the fruit has been suggested – Ecballium elaterium – a species that grows abundantly in Italy. Ejection of seed under pressure, and the fruit’s use as an abortifacient, may symbolically embody the subject of Botticelli’s masterpiece.
Brown, M 2018. Death in the garden. Poisonous plants & their use throughout history. White Owl.
Fahn A and Werker E 1972. Anatomical mechanisms of seed dispersal. In Kozlowski TT (ed) Seed biology. Vol. 1. Importance, development and germination. Academic Press, pp. 151-222.