Mimosa pudica var. unijuga – Sensitive Plant

Mimosa pudica var. unijuga - Sensitive Plant, Shameplant (flower head and leaf)

Mimosa pudica var. unijuga - Sensitive Plant, Shameplant (seedpods)

Plant Name

Scientific Name: Mimosa pudica var. unijuga

Synonym: Mimosa unijuga

Common Names: Sensitive Plant, Shameplant

Plant Characteristics

Duration: Annual, Perennial

Growth Habit: Herb/Forb

Hawaii Native Status: Introduced. This naturalized ornamental plant is native to tropical America, but it has now become a pan-tropical weed.

Flower Color: Pink

Height: To 39 inches (1 m) tall

Description: The flower heads are spherical to egg-shaped balls of numerous tiny, reddish pink flowers, each with 4 long, paler pink stamens. The flowers are followed by clusters of small, flat, elongated, pearl necklace-shaped bean pods with prickly margins that allow them to adhere to socks and animal fur. The leaves are bipinnately compound with 1 or 2 pairs of pinnae, each with 10 to 26, green, linear-oblong leaflets. The distinctive characteristic of this plant is that the leaves will immediately droop and fold up if touched or if the plant is shaken. The leaves are also nyctinastic, which means that they close up at night. The stems are reddish brown, prickly, branching, and upright to more commonly trailing, especially in older plants.

Here in Hawaii, Sensitive Plant is a common lawn and pasture weed.


Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Subclass: Rosidae
Order: Fabales
Family: Fabaceae – Pea family
Genus: Mimosa L. – sensitive plant
Species: Mimosa pudica L. – shameplant
Variety: Mimosa pudica L. var. unijuga (Duchass. & Walp.) Griseb. – shameplant

More About This Plant

Hawaii County Distribution Map