Chamaecrista ramosa

Chamaecrista ramosa is a small leguminous subshrub or perennial herb in the pea family (Fabaceae, subfamily Caesalpinioideae), belonging to the section Xerocalyx of the diverse genus Chamaecrista (the sensitive peas). The species is native to South America, where it occurs widely in the cerrado, caatinga, and campos rupestres of Brazil, extending to neighbouring regions of Venezuela and the Guianas, with several recognised infraspecific varieties (var. curvifolia, var. erythrocalyx, var. lucida, var. parvifoliolata, var. ramosa and var. ventuarensis). Plants are much-branched from a woody base, with slender stems bearing small, paripinnate leaves composed of several pairs of narrow, oblong leaflets; the foliage shows weak nyctinastic movement typical of the genus. Solitary or paired bright yellow flowers arise from the leaf axils on slender pedicels and consist of five subequal petals, the lowermost often slightly larger, with a tuft of conspicuous stamens of unequal length. The fruit is a flat, linear pod that dehisces explosively at maturity to scatter the small, hard, dark seeds. The species, like other Chamaecrista, forms root nodules with nitrogen-fixing bacteria.