Sensitive Plant

Appearance

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. The leaves of the mimosa pudica are compound leaves.

The leaves are bipinnately compound, with one or two pinnae pairs, and 10–26 leaflets per pinna. The petioles are also prickly. Pedunculate 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. 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 pollinated by the wind and insects. The seeds have hard seed coats which restrict germination....hieroglyph snipped...

Naming

The species is known by numerous common names including
⤷ sensitive plant
⤷ humble plant
⤷ shameful plant
⤷ sleeping grass
⤷ touch-me-not
⤷ chuimui
⤷ ant-plant
Non-English common names in other European language/culture areas include "não-me-toque", "sensitiva" or "dormideira" in the Portuguese language, while in Spanish it varies in names such as "morí-viví" or "moriviví" and "dormilona".

In Austronesia names vary more: in the Philippines it is called "makahiya", with maka- meaning "quite" or "tendency to be", and -hiya meaning "shy", or "shyness"), while in Tonga for example it is known as "mateloi", being "putri malu" in Indonesia and "pokok semalu" in Malaysia. In Sinhala it is called "Nidi Kumba".

In South Asia many unrelated names are also common. In Hindi it is known as "chhui-mui". In Bengali, the shrub is known as "lojjaboti". In Malayalam it is called "thottavaadi". In Marathi it is called "lazalu". In Tamil, it is called "thotta-siningi" and in Kannada, it is known as "muttidare muni". In Burmese it is called "hti ka yoan", which means "crumbles when touched".

In Liberia it is known as the "pickerweed".

Distribution

"Mimosa pudica" is native to South America and Central America. It has been introduced to many other regions and is regarded as an invasive species in Tanzania, South Asia and South East Asia and many Pacific Islands. It is regarded as invasive in parts of Australia and is a declared weed in the Northern Territory,...hieroglyph snipped... and Western Australia although not naturalized there. Control is recommended in Queensland. It has also been introduced to Nigeria, Seychelles, Mauritius and East Asia but is not regarded as invasive in those places. In the United States of America, it grows in Florida, Hawaii, Virginia, Maryland, Puerto Rico, Texas, and the Virgin Islands.

Cultural

The species can be a troublesome weed in tropical crops, particularly when fields are hand cultivated. Crops it tends to affect are corn, coconuts, tomatoes, cotton, coffee, bananas, soybeans, papaya, and sugar cane. Dry thickets may become a fire hazard. In some cases it has become a forage plant although the variety in Hawaii is reported to be toxic to livestock.

"Mimosa pudica" can form root nodules that are habitable by nitrogen fixing bacteria....hieroglyph snipped... The bacteria are able to convert atmospheric nitrogen, which plants cannot use, into a form that plants can use. This trait is common among plants in the Fabaceae family.