Shameplant- Mimosa Pudica- Super Touch Responsive plant
Mimosa pudica[3] (from Latin: pudica "shy, bashful or shrinking"; also called sensitive plant, sleepy plant, action plant,[4] Dormilones, touch-me-not, shameplant, or shy plant) is a creeping annual or perennial flowering plant of the pea/legume family Fabaceae and Magnoliopsida taxon, often grown for its curiosity value: the compound leaves fold inward and droop when touched or shaken, defending themselves from harm, and re-open a few minutes later.[5] Perhaps this reflex was an adaption to predators and is a defense mechanism to scare predators away, or maybe it is an adaption to retain more water by shading itself to decrease water loss by heat of evaporation. The species is native to South America and Central America, but is now a pantropical weed. It can also be found in Asia in countries such as Bangladesh, Thailand, India, Indonesia, Malaysia, Philippines, Vietnam, Cambodia, Laos, Japan, Sri Lanka and well across the southern part of the United States. It is also found as an invasive weed in Far North Queensland, Australia. It grows mostly in undisturbed shady areas, under trees or shrubs.
Taxonomy
Mimosa pudica was first formally described by Carl Linnaeus in Species Plantarum in 1753.[6] 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
Mimosa pudica flower from Thrissur, Kerala, India
Flower
Mimosa pudica folding leaflets inward.
Mimosa pudica seeds
Mimosa pudica with mature seed pods on plant
The whole plant of Mimosa pudica includes thorny stem and branches, flower head, dry flowers, seed pods, and folded and unfolded leaflets
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 1.5 m (5 ft).
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. The globose to ovoid heads are 8–10 mm 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 lavender. The fruit consists of clusters of 2–8 pods from 1–2 cm long each, these being prickly on the margins. The pods break into 2–5 segments and contain pale brown seeds some 2.5 mm long. The flowers are insect pollinated and wind pollinated.[7] The seeds have hard seed coats which restrict germination and make osmotic pressure and soil acidity less significant hindrances. High temperatures are the main stimuli that cause the seeds to end dormancy.[8]
The roots of Mimosa pudica create carbon disulfide, which prevents certain pathogenic and mycorrhizal fungi from growing within the plant’s rhizosphere.[9] This allows the formation of nodules on the roots of the plant that contain endosymbiotic diazotrophs, which fix atmospheric nitrogen and convert it into a form that is usable by the plant.[10]
Mimosa pudica is a tetraploid (2n = 52).[11]
Plant movement
File:Mimosa pudica in Hainan.ogv
Video of Mimosa pudica closing when touched in Hainan, China
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.[12] This was first studied by the French scientist Jean-Jacques d'Ortous de Mairan.
The leaflets also close when stimulated in other ways, such as touching, warming, blowing, shaking, which are all encapsulated within mechanical or electrical stimulation. These types of movements have been termed seismonastic movements. The main structure mechanistically responsible for the drooping of the leaves is the (pulvinus). The stimulus is transmitted as an action potential from a stimulated leaflet, to the leaflet's swollen base (pulvinus), and from there to the pulvini of the other leaflets, which run along the length of the leaf's rachis. The action potential then passes into the petiole, and finally to the large pulvinus at the end of the petiole, where the leaf attaches to the stem. The pulvini cells gain and lose turgor due to water moving in and out of these cells, and multiple ion concentrations play a role in the manipulation of water movement. Ions cannot easily move in and out of cells, so protein channels such as voltage-gated potassium channels and calcium-permeable anion channels are responsible for allowing potassium and calcium, respectively, to flow through the cell membrane,