Bimucronate mimosa

Mimosa bimucronata, sometimes called the bimucronate mimosa, maricazinho or giant sensitive tree, is a thorny shrub or small tree of the family Fabaceae, native to South America, especially Brazil and neighbouring countries, where it grows along riverbanks, in wet lowlands, pastures and disturbed ground, often forming dense, impenetrable thickets. It reaches about 3 to 8 metres in height, with branches armed with scattered, sharp, recurved prickles. The leaves are bipinnate and fern-like, divided into many small, narrow leaflets, and are mildly sensitive to touch and to nightfall, folding in the manner characteristic of the genus though less dramatically than the true sensitive plant. The small flowers are crowded into dense, globose, fluffy creamy-white heads borne in the leaf axils, the showy element being the numerous projecting stamens. These are followed by clusters of flat, jointed pods that break into one-seeded segments at maturity. A fast-growing, nitrogen-fixing pioneer, it is often regarded as a troublesome weed of waterways and is also used locally for fuel and as a living fence.