Annual or perennial herbs, shrubs or rarely trees; branches usually articulate or swollen at nodes. Leaves opposite or alternate (by suppression) or fasciculate, pinnate, rarely simple, entire, petiolate to subsessile; stipules free, foliaceous, sometimes fleshy or spinescent, rarely deciduous. Flowers solitary or in cymes, usually bisexual, actinomorphic or rarely zygomorphic, 5-merous, hypogynous. Sepals usually 5, free or rarely connate at base, imbricate or valvate. Petals usually 5, free, often clawed, imbricate or convolute, rarely absent. Disk convex or concave, rarely annular or indistinct. Stamens in 1-3 whorls of 5 each, free, outermost whorl usually opposite petals and occasionally adnate at base; filaments appendaged at base or naked; anthers basifixed to versatile, longitudinally dehiscent, introrse. Carpels 5, ovary sessile or rarely shortly stipitate, angled or winged, (2-)6-10(-12)-locular, axile placentation; style simple, angular or furrowed, rarely 5 and free; stigma simple, capitate or lobed. Fruit capsular or schizocarp, rarely drupaceous or baccate; seeds 1-many in each locule; endosperm present or absent; cotyledons flat.

22 genera and about 154 species

Tribulus terrestris