A dense glabrous  shrub up to 0.5 to 1 m. Leaves alternate, simple, opposite, elliptic or elliptic-lanceolate, acuminate. Flowers white, in dense spikes, white; bracts ovate or obovate; calyx deeply five-lobed; stamens glabrous. Fruits  four seeded capsules with a solid base. Seeds  glabrous. Flowering and fruiting between.February-May.
The tree is a common shrub distributed throughout India.
 

It has a spread around 1.8–3.0 m (6–10 ft) with gray-green leaves of 0.9–1.5 m (3–5 ft) long, each with a prickly margin and a heavy spike at the tip that can pierce deeply. Near the end of its life, the plant sends up a tall, branched stalk, laden with yellow blossoms, that may reach a total height up to 8–9 m (25–30 ft).

The tree is native in the tropical and subtropical regions of the world mainly in desert.
 

is an evergreen perennial subshrub, stemless or with a short stem up to 1 m tall. The leaves are sword-shaped, 1-1.8 m long and 10–15 cm broad at their widest point, narrowing to 6–7 cm broad at the leaf base, and to a sharp spine tip at the apex; the margins are entire or with a few hooked spines. The flowers are greenish to creamy white, 4 cm long, and strongly scented. 
The tree is native to the Caribbean and northern South America

an erect trunk, 3–5 in (7.6–12.7 cm) in diameter, reaching up to 5–20 ft (1.5–6.1 m) tall. flowers are white and showy, sometimes tinged purplish, so that the plant is popular as an ornamental. Fruits are elongated, fleshy, up to 5 cm long. It is widely planted in hot climates and arid environments.
The tree is native to the Atlantic and Gulf Coasts of the United States from southern Virginia south to Florida and west to the Texas Gulf Coast, to Mexico along the Yucatán coast, and to Bermuda, and parts of the Caribbean
 

A fast growing, evergreen, thornless shrub, reaching a height of 5 m to 20 m. Leucaena is a long-lived perennial legume. It has a deep taproot and is highly branched. Leaves are bipinnate, bearing numerous leaflets 8 mm to 16 mm long. The inflorescence is a cream coloured globular shape producing clusters of flat brown pods, 13 to 18 mm long containing 15-30 seeds. Flowering and fruiting occur throughout the year.
The tree is native to Guatemala and Mexico.