Euphorbia bongolavensis is a member of one of the largest and most diverse flowering plant families in the world, the Euphorbiaceae (5) (6) (7), which contains around 7,500 species (6). The shape and size of the leaves of Euphorbiaceae species are highly variable, although they are usually deciduous and the leaf stalks are often reduced to thorns (6) (7). The succulent Euphorbia species found in Africa and Madagascar are similar in appearance to the cacti of North and South America (7).
The peeling bark on the stalk of Euphorbia bongolavensis is arranged into thin rings. There is a rosette of egg-shaped leaves at the tip of the stalk, which are bright red at the base (2) (3).
This species in included in the genus Euphorbia, characterised by their extremely simple flowers (8). Species within this genus have a miniature inflorescence called the ‘cyathium’, which has a single female flower in the centre surrounded by several male flowers. All of the flowers are enclosed in the ‘involucre’, a series of bracts arrange in a cup shape (5) (6) (7) (8). Nectar-producing glands can usually be found between the bracts (6). This unique feature is not seen in any other genera of the plant kingdom, although some Euphorbia species do not possess this feature (5) (6) (7).
The fruit of Euphorbia species is an explosive capsule which bursts open when it is ripe, shooting out three or more seeds with a huge force (5) (6) (7). The shape and size of these capsules is highly variable (5).
- Height: up to 100 cm (2) (3)