Chamaecrista nictitans
Chamaecrista nictitans, the sensitive cassia, sensitive partridge pea, small partridge pea or wild sensitive plant, is a herbaceous species of legume widely distributed through the temperate and tropical Americas. It is an annual plant capable of rapid plant movement—its leaflets fold together when touched. It is similar to "Chamaecrista fasciculata" except that the leaves are smaller. "C. nictitans" is undesirable as a forage or hay but "can" be used for both in subtropical areas.