Mimosa pudica is an annual to perennial, more or less prostrate creeping plant.
The plant can grow up to 1 metre tall, but is more likely to be 15 - 45cm tall, the stems usually becoming woody.
The plant is gathered from the wild for local medicinal use. It is cultivated as a green manure and for soil stabilization, and is sometimes also cultivated for its uses in folk medicine.
It is commonly grown as an ornamental, being valued especially for the novelty of its leaves drooping downwards whenever touched.
Mimosa pudica is very widespread in Central America, South America and the Caribbean. This taxon is known to occur within a number of protected areas throughout the species range and seeds have been collected and stored by the Millennium Seed Bank Project as a method of ex situ conservation. It is common and not considered to be threatened or in decline. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species (2013).

Known Hazards

When the prickles on the stem and the fruits become too hard, they can cause intestinal inflammation in grazing animals.
The roots are toxic in large doses.

Habitat

Croplands, orchards, pastures, mowed areas, roadsides, areas disturbed by construction, moist waste ground, open plantations, and weedy thickets at elevations from sea level to 1,300 metres. It may grow as a single plant or in tangled thickets.

Cultivation Status

Cultivated, Ornamental, Wild

Cultivation Details

A plant of the tropics, but also naturalized in the subtropics, where it is found at elevations up to 1,300 metres. It grows best in areas where annual daytime temperatures are within the range 22 - 28°c, but can tolerate 10 - 32°c.
It is intolerant of frost.
It prefers a mean annual rainfall in the range 1,000 - 2,000mm, but tolerates 900 - 3,000mm.
Prefers a sunny position, but can succeed in quite dense shade.
Plants are shade intolerant.
Succeeds in most soils, including those that are shallow or poor in nutrients.
The plant is well adapted to humid areas with high winds.
Prefers a pH in the range 6 - 7, tolerating 5 - 7.5.
The plant has become naturalized throughout the Tropics and much of the subtropics.
It has become a pest in forest plantations, cropland, orchards and pasture.
It is particularly likely to become a noxious weed when growing in dryland field crops, in rainfed wetland rice and in plantation crops.
Plants can flower all year round.
Plants are a fire hazard when dry.
Although they can be perennial, the plants can also complete their life-cycle within 90 days.
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.

Edible Uses

The delicately fragrant flowers can be crystallized, or used in the preparation of distilled flower water.
An oil similar to soybean oil (Glycine max) is obtained from the seed.

Medicinal

According to Ayurveda, the root is bitter, acrid, cooling, vulnerary, alexipharmic. It is used in treatment of biliousness, leprosy, dysentery, vaginal and uterine complaints, inflammations, burning sensation, fatigue, asthma, leucoderma, blood diseases etc.
According to the Unani system of medicine, the root is resolvent, alternative, useful in diseases arising from blood impurities and bile, bilious fevers, piles, jaundice, leprosy etc.
The root is used to control alcoholism.
The leaves are bitter, mildly sudorific, tonic.
A leaf tincture is given by teetotallers to drunkards to remedy drunkenness.
The seed is emetic.
The plant contains the alkaloid 'mimosine'.
Extracts of the plant have been shown in scientific trials to be a moderate diuretic; to depress duodenal contractions in a similar manner to atropine sulphone; to promote regeneration of the nerves; and reduce menorrhagia.
The roots contain tannin, ash, calcium oxalate crystals and mimosin.
Root extracts are reported to be a strong emetic.

Agroforestry Uses

The plant forms a dense ground cover and has been used to provide ground cover in coconut plantations.
It has been introduced to subtropical, humid areas of the Transcaucasus where it is cultivated for erosion control, ground cover and green manure.
The plant has been identified as having potential for phytoremediation of arsenic polluted areas in Thailand.

Other Uses

None known

Propagation

Seed - it has a hard seedcoat and may benefit from scarification before sowing to speed up germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time, they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing.