Southwest Desert Flora

The Fabaceae or Leguminosae Family
Legume, Pea and Bean Family

The Fabaceae or Leguminosae Family is the 3rd largest plant family world-wide behind Orchidaceae and Asteraceae. They are commonly known as the legume, pea or bean family. This is one of only a few families with two acceptable scientific family names; Fabaceae and Leguminosae.

In North America there are 245 genera with over 2,694 accepted taxa overall for the genus Fabaceae (Leguminaceae). The Plant List includes 917 genera with 23,535 accepted species names and a further 10,354 scientific plant names of infraspecific rank for the family Leguminosae.

The Fabaceae is a large and economically important family with representative growth forms that include trees, shrubs, perennial and annual species. The family is easy to identify by their flowers, fruit (legume) and leaves (compound); 3 significant taxonomic characteristics.

Detarioideae: 84 genera, (Amherstia, Detarium, Tamarindus)

Duparquetioideae: 1 genus, (Duparquetia)

Dialioideae: 17 genera, (Dialium)

Caesalpinioideae: 148 genera, (Acacia, Caesalpinia, Hoffmannseggia, Mimosa, Senna. Includes subfamily Mimosoideae (80 genera) and

Faboideae: 503 genera (Acmispon, Astragalus, Dalea, Desmodium, Erythrina, Lotus, Lupinus, Macroptilium, Medicago, Melilotus, Olneya, Phaseolus, Psorothamnus, Robinia, Sesbania, Sophora, Thermopsis, Trifolium, Vicia)

The 5 largest genera in this family include Astragalus; (2,481 species), Acacia; (1,380 species), Indigofera; (665 species), Crotalaria; (698 species) and Mimosa; (618 species).

Important agricultural, food and forage plants can be traced back to human civilization where they were recoginized for their important source of protein. because of the ability to fix nitrogen from the air meant that they could be used to reduce fertilizer costs and for crop rotation to replace soil nitrogen. Legume plants have been identified in use for a wide range of purposes from forage, grain, flowers, pharmaceutical, soil amendments and timber. Alfalfa and clover have been and are grown for forage and other species have been grown for food such as peas, chickpeas, peanuts, sweet peas and lupines and soybeans. Timber production is also an important agricultural crop and includes species of Acacia and Dalbergia.

Important ornamentals have been in horticultural use as ornamentals for many centuries. Ornamental plants include all shapes, sizes and color that are used on both large scale park type gardens to individual homeowner gardens.