Caesalpinia bonduc, commonly known as grey nicker, nicker bean, fever nut, or knicker nut, is a medicinal plant. Guilandina bonduc grows as a climber, up to 8 m (30 ft) long, or as a large sprawling shrub or small shrubby tree. The stems are irregularly covered with curved prickles. The leaves are large and bi-pinnate, up to 40 cm (16 in) long with scattered prickles on the rachises and blades. The sepals are shorter than the petals which are around 10 mm (0.4 in) long; the petals are yellow, sometimes with a spot of orange near the base of the keel. The flowers are followed by large, flattish, spiny green pods which later turn brown, some 9 by 4 cm (4 by 2 in), containing one or usually two, glossy, rounded, grey seeds.