Tribulus terrestris, commonly devil’s thorn or in Afrikaans dubbeltjie (little double), is an annual that branches into many prostrate stems becoming up to 1,5 m long. The plant is generally hairy, the hairs long and whitish.
The paripinnate leaves (no terminal leaflet) are made up of opposite, stalkless leaflets, ovate in shape, tapering to acutely pointed tips. The leaflets have whitish midribs, the blades angled up along their rachis. The upper pair is usually slightly smaller than the rest.
Solitary yellow flowers grow from leaf axils. The five petals spread or form a shallow bowl. The petals have rounded to flat tips, longitudinal pleat lines and in picture a darker yellow lower part. There are ten stamens with cylindrical yellow anthers.
The hard fruit, initially green, has long rigid spines and small spinules. About all that walked barefoot in southern Africa as children remember the fruit, if not the flower. The generic name is derived from the Greek word, tribolos, meaning three-pronged or three-pointed. The specific name, terrestris, is Latin for of or on the earth or land.
The species is found throughout southern Africa, the plants growing on sandy flats and disturbed places (Manning, 2009; Van Wyk and Malan, 1997; Andrew, 2017; http://redlist.sanbi.org).