Leguminous Trees

Leguminous trees are named after the fruits they produce and are members of the legume, or Fabaceae, family. The Fabaceae family is the third largest flowering plant family, with more than 18,000 members. Legume trees produce pods that contain their seeds. These seed pods come in a variety of sizes and shapes, ranging from giant 5-foot-long pods that grow in tropical forests to the common soybean, peanut and green bean. Several varieties of leguminous trees are grown as ornamental trees in the U.S.

Leguminous trees are Nitrogen fixing trees they are often deep rooted, which allows them to gain access to nutrients in subsoil layers. Their constant leaf drop nourishes soil life, which in turn can support more plant life. The extensive root system stabilises soil, while constantly growing and atrophying, adding organic matter to the soil while creating channels for aeration. There are many species of NFTs that can also provide numerous useful products and functions, including food, wind protection, shade, animal fodder, fuel wood, living fence, and timber, in addition to providing nitrogen to the system.


  1. Western Redbud

    • The western redbud (Cercis occidentalis) is native to the southwestern U.S. and produces multiple trunks. It grows in a dense, vase shape to 25 feet with a similar spread. This deciduous tree produces showy pink and purple flowers in spring, followed by brown, bird-attracting legumes. Its pinnate, green foliage turns yellow in fall.


    • The mimosa (Albizia julibrissin) grows to 35 feet tall with a 30-foot spread. This deciduous tree has delicate, lacy foliage and a wide, spreading canopy. It blooms from spring through summer with showy, puffy, pink blooms followed by hard, dry seed pods. The mimosa has large, thick surface roots and is considered a weed in some states.


    • The tamarind tree (Tamarindus indica) grows up to 65 feet tall with a 50-foot spread. This tropical evergreen grows in an upright, rounded form and produces red to yellow flowers in spring, followed by hard, velvety, brown legumes that grow up to 6 inches long and are filled with an edible paste. Tamarinds only grow in frost-free regions.

    Blue Paloverde

    • The blue paloverde (Parkinsonia florida) grows from 30 to 40 feet tall and has smooth, blue-green bark. This thorned tree blooms with bright yellow flowers in spring and produces flat green legumes that turn yellow as they mature. Blue paloverde flowers attract bees.

    Catclaw Acacia

    • The catclaw acacia (Acacia greggii) grows to 20 feet tall as a small tree or large shrub. This thorny tree has curved brown and gray spines along its branches and binately compound foliage. It blooms with clusters of yellow flowers in spring, followed by long, flat seed pods.

    Velvet Mesquite

    • Velvet mesquite trees (Prosopis velutina) produce long, green pods that turn brown as they age. This 30-foot-tall tree has straight, white-gray thorns and brown to gray bark. The velvet mesquite has extremely long taproots that reach as deep as 160 feet under the earth.

    Desert Ironwood

    • The desert ironwood (Olneya tesota) grows to 35 feet tall and produces brown, hairy legumes. It blooms with pea-shaped white to dark-purple blossoms and has fissured, gray bark and curved spines. The desert ironwood grows almost exclusively in the Sonoran Desert and is a protected species in Arizona. Unlike most trees, desert ironwood wood does not float.

    Whitethorn Acacia

    • The whitethorn acacia (Acacia constricta) also grows as a small tree or large shrub. It reaches heights of 10 feet and has red, burgundy to gray bark. Older woody growth loses its spines, but new growth has straight, white thorns. It produces red-brown legumes and blooms with fuzzy yellow flowers in spring and midsummer.


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