Carissa spinarum is a multi-stemmed, evergreen spiny shrub (spinarum) that can grow up to 3 m tall. Its leaves are shiny, and the plant contains a white latex. The white flowers are starred and fragrant. The fruits become dark purple when ripe.
This native species of the Mascarene Islands is part of the vegetation of the undergrowth. It grows as well in intermediate and upland forests. The flowers are pollinated by flies and bees and fall at the foot of the mother plant. Seedlings are sometimes found in the wild. Some adult plants were found in Rodrigues, Mauritius and Réunion.
C spinarum is classified as ‘Critically Endangered’ on the IUCN Red List. Seed propagating trials in nurseries have been successful, but seedling growth seems difficult. The plant is protected under the forest restoration project and on private reserves. The population is threatened by habitat loss and the invasion of exotic species.
In traditional medicine, the plant is recognized for its anthelmintic properties (vermifuge) both in humans and animals. Its crushed root is used as a remedy against venereal diseases. The chewed root leaves a bitter taste in the mouth (hence its vernacular name).
The sap of the root is considered invigorating and "restorative" of virility. The roots contain an active ingredient, Carissa, which may be useful in the treatment of cancers.
The plant was described in 1767 by Carl von Linné, Swedish botanist, physicist and zoologist known as the "father of modern taxonomy".