Mimosa pudica (; also called sensitive plant, sleepy plant, action plant, touch-me-not, or shameplant) is a creeping annual or perennial flowering plant of the pea/legume family Fabaceae. It is often grown for its curiosity value: the sensitive compound leaves fold inward and droop when touched or shaken and re-open a few minutes later. Mimosa pudica is not a carnivorous plant. In the UK it has gained the Royal Horticultural Society's Award of Garden Merit. The species is native to the Caribbean and South and Central America, but is now a pantropical weed, and can now be found in the Southern United States, South Asia, East Asia, Micronesia, Australia, South Africa, and West Africa as well. It is not shade-tolerant and is primarily found on soils with low nutrient concentrations. Mimosa pudica is well known for its rapid plant movement. Like a number of other plant species, it undergoes changes in leaf orientation termed "sleep" or nyctinastic movement. The foliage closes during darkness and reopens in light. This was first studied by French scientist Jean-Jacques d'Ortous de Mairan. Due to Mimosa unique response to touch, it became an ideal plant for many experiments regarding plant habituation and memory. Taxonomy Mimosa pudica was first formally described by Carl Linnaeus in Species Plantarum in 1753. The species epithet, pudica, is Latin for "bashful" or "shrinking", alluding to its shrinking reaction to contact. The species is known by numerous common names including sensitive plant, humble plant, shameplant, and touch-me-not. Description The stem is erect in young plants but becomes creeping or trailing with age. It can hang very low and become floppy. The stem is slender, branching, and sparsely to densely prickly, growing to a length of . The erect height of M. pudica usually reaches around ~30cm (~1ft). The leaves are bipinnately compound, with one or two pinnae pairs, and 10–26 leaflets per pinna. The petioles are also prickly. Pedunculate (stalked) pale pink or purple flower heads arise from the leaf axils in mid-summer with more and more flowers as the plant gets older. A single flower survives for less than a day, and usually dies completely by the next day. Flowers of M. pudica are very brittle and soft. The globose to ovoid heads are in diameter (excluding the stamens). On close examination, it is seen that the floret petals are red in their upper part and the filaments are pink to