The stem is erect in young plants, but becomes creeping or trailing with age. 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. 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 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.

Plant movement

Mimosa pudica is well known for its rapid plant movement. In the evening the leaflets will fold together and the whole leaf droops downward. It then re-opens at sunrise. This type of motion has been termed nyctinastic movement. The leaves also close up under various other stimuli, such as touching, warming, or shaking. The stimulus can also be transmitted to neighbouring leaves. These types of movements have been termed seizmonastic movements. The movement is caused by "a rapid loss of pressure in strategically situated cells that cause the leaves to droop right before one’s eyes".This characteristic is quite common within the mimosaceae family.

Mimosa pudica is sold as an educational product and novelty gift sometimes under the trademark name TickleMe Plant.

Medicinal properties

The plant lajjalu described in Ayurveda has been identified as Mimosa pudica. This plant has several alternate Sanskirt common names, including Namaskari, and Rakta Paadi.

In Ayurveda, the plant is described as a plant which folds itself when touched and spreads its leaves once again after a while. It is said to have a bitter and astringent taste, and has a history of use for the treatment of various ailments. Most commonly used is the root, but leaves, flowers, bark, and fruit can also be implemented.

Ayurvedan Properties (Guna) of Lajjalu

• Has tikta and kashaya rasa (bitter and astringent taste).
• Has property of cold (sheetha).
• Balances Kapha, Pitta.
• Shushrutha has placed this plant in Priyangwambhastaadi gana