The genus name Mimosa comes from the Greek mimos meaning “mimic” or “mime” in reference to the leaves of some species which move when touched, seeming to mimic consciousness.
Admired for its fernlike foliage and strikingly fluffy, pink-tinged flowers, the mimosa tree (Albizia julibrissin) has been planted as a garden ornamental in the United States since the 18th century. The deciduous tree grows quite quickly, usually adding 2 or more feet of height per year. It also reaches an eventual spread of 20 to 50 feet, giving it a flattened, spreading form, showcasing a broad, open canopy with a picturesque silhouette. Mimosas are quick to establish and tolerant of a range of cultural conditions, though they are notably susceptible to some pests and diseases.
The showy flowers attract butterflies to the garden, but although the tree is deciduous, there is no colorful fall foliage. It has bipinnate compound leaves, which means smaller leaflets adorn larger, fern-like leaf arrangements. It can be quite invasive, however, so avoid planting mimosa tree in areas where it is already growing invasively or in watershed areas where streams will distribute seeds.
Although the tree is quite attractive, its leaves, flowers and pods pose a serious litter problem. You should not plant it anywhere that receives high traffic, or where removing the litter will present a nuisance. Its short lifespan and brittle, easily broken limbs are also inconvenient, and add to its reputation as a poor landscape tree. However, if you like the look of the tree and possess an open area in which to plant and admire it, it makes a nice specimen to accent your yard.
List of common varieties of mimosa tree
- Mimosa aculeaticarpa (Catclaw mimosa)
- Mimosa diplotricha (Giant sensitive plant)
- Mimosa microphylla (Littleleaf sensitive-briar)
- Mimosa nuttallii (the Nuttall’s sensitive-briar)
- Mimosa ophthalmocentra (jurema-embira)
- Mimosa quadrivalvis (Fourvalve mimosa)
- Mimosa strigillosa (Sunshine mimosa)
- Mimosa rubicaulis (Himalayan Mimosa)
- Mimosa scabrella (Bracatinga mimosa)
- Mimosa pudica (Humble plant)
Catclaw mimosa
The catclaw mimosa also referred to as the wait-a-minute bush is a straggling thicket forming shrub, usually growing to about one metre tall but occasionally double that height. The twigs are hairy and armed with backward pointing spines that easily catch in clothing.
The alternate leaves are bi-pinnate with a varying number of small oblong leaflets. The flowers are white or pale pink, bunched together in globular heads. The fruits are flat pods up to four centimetres long, flattened between the seeds and splitting open when ripe.
Giant sensitive plant
Giant sensitive plant is commonly referred to as the giant false sensitive plant, or nila grass grows as an erect shrub or a scrambling climber, reaching a height of around 3 m (9.8 ft). Its leaves are bipinnate and bright green with a feathery appearance. They are arranged alternately along the stems. Each leaf contains around twenty pairs of small sessile lanceolate leaflets arranged opposite each other.
The stems are characteristically very long. They are squarish in cross-section, with four ridges running lengthwise. The flowers are pale pink and looks like a clustered fluffy ball.
Giant Mimosa is fast-growing and can tolerate a wide range of soil and climate conditions. Left alone, they can form impenetrable thickets within a short period that can affect movement of both people and animals, as well as planted crops.
Littleleaf sensitive-briar
Known also by the names of little-leaf mimosa, catclaw sensitive briar, and smooth-leaf sensitive briar, this herbaceous perennial is a sprawling vine with a prickly stem. It has compound leaves, with 4-8 pairs of small leaflets per leaf.
Its leaves are sensitive to touch, and fold together immediately after being disturbed. It produces round heads of purple flowers from June to September. Its typical natural habitat is in dry woodlands and forests, although it can also be found in disturbed areas.
Nuttall’s sensitive-briar
The ribbed stems of this plant usually grow to 4 ft (1.2 m) or more and are branched. Plants rarely reach more than 1–2 ft in height. The frond-like leaves are alternate with prickly stalks. Habitat includes disturbed areas of sandy or silty soils, roadsides, grasslands, prairies and forest margins.
The tiny flowers occur in congested bunches. Before they open, they look much like small green bramble fruits. Each individual flower has five minute petals and eight to ten conspicuous stamens. When open, the pink-purple stamens form a globelike cluster at the tip of their leafless stalk. Other common names for this plant include Nuttall’s sensitive briar and shame-boy, a reference to the sensitive foliage that closes upon touch.
Fourvalve mimosa
Mimosa quadrivalvis, commonly called sensitive brier or fourvalve mimosa, is a herbaceous, taprooted perennial native to open, sandy pinewoods, scrublands, glades, and undisturbed grasslands.
It is a sprawling plant with alternate leaves. Each leaf is compound with up to 16 pairs of leaflets that fold together when touched. The stem is covered with small recurved prickles.
The flowerheads comprise round clusters of numerous pink flowers, each flower only 3 mm long with exserted stamens. The fruits are also prickly. Flowering occurs from May through September. Its habitat includes glades, open woods, thickets, prairies, and roadsides.
Sunshine mimosa
Mimosa strigillosa is also referred to as as sunshine mimosa and powderpuff. The name powderpuff refers to the small spherical flowers that rise above the plant’s creeping vines. Like related species in the genus Mimosa, sunshine mimosa has sensitive leaves that can fold in a matter of seconds after being disturbed.
Sunshine mimosa is mat forming and is capable of spreading rapidly and as few as four or five pots may cover 300 square feet in a single growing season. The plant is also recommended as a turfgrass replacement because of its ability to withstand some foot traffic and mowing.
Himalayan Mimosa
Himalayan mimosa is a large, straggling, very prickly shrub. It flowers from June to September, sporting long clusters of many pink spherical flower heads 1–2 cm across. The flowers fade to white, so the clusters sport both pink and white flower-heads most of the time. Leaves are double-compound, 8–15 cm long, with thorny rachis.
It is considered useful for hedges. The wood is suitable for tent pegs and for making gunpowder charcoal. Roots and leaves are used medicinally. Himalayan Mimosa is found in the Himalayas. It prefers forest edges and boundaries of fields and gardens.
Bracatinga mimosa
This is one of the fastest growing trees in the world. Within 14 months, Mimosa bracatinga grows up to 16 ft, in 2 years it reaches 26–30 ft, and in 3 years it can grow to a height of 49 ft. The leaves are bi-pinnate. Each leaf has several pinna, which again have several pairs of pinnules. The upper side of the leaves is yellow-green coloured with a paler underneath.
The flowers with ovary, narrow and slender pistils are ordered in clusters of 1–3 at the leaf bases. They are colored in a whitish to yellow color. Its wood is suitable for firewood and can also be used as lumber. The long fibres are used for paper production.
Mimosa pudica
Mimosa pudica also referred to as sleepy plant or action plant. It is 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. It is not shade-tolerant and is primarily found on soils with low nutrient concentrations.
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 5 ft. 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.