The Succulent Plant Page goes to Families of Succulent Plants goes to

The Bean Page
Fabaceae ( = Leguminosae)

Search this site:        
Botanical BookmarksBotanical Glossary SITEMAP Email: webmaster

dish of beans The Fabaceae is a very large and importamt family of 650 genera and over 18,000 species of dicotyledenous flowering herbs and trees, commonly called legumes or pulses. The family is numerically the third largest after Orchidaceae and Asteraceae respectively. Flowers have five petals and a superior ovary. One of the unifying characteristics is the dehiscent seed pod with seeds present in a row, sometimes in individual sections. Flowers have 10 or more stamens. A common feature is symbiosis with nitrogen-fixing bacteria, which reside in special root nodules and fix atmospheric nitrogen to nitrate assisting the plants' growth on poor soils. When used as a green manure they add nitrogen to the soil.
 
The Fabaceae are of great agricultural importance as food crops (beans, lentils, peanuts, peas, soybeans) and fodder crops or green manure (alfafa, clover, lupins, soybean). However, many species contain toxic lectins and other poisons in their seeds. Even with edible pulses, it is advisable to boil them vigorously to destroy their lectins. The family includes many ornamental (Acacia, Laburnum, Mimosa) and xerophytic trees (Acacia, Mesquite, Paolo Verde), distributed across both the Old and New Worlds.
 
Succulent genera: Cassia, Dolichos, Elephantorrhiza, Erythrina, Neorautenania, Senna.

Erythrina  Linnaeus 1753 (Coral Trees)
Greek: erythros = red

This family includes around 130 species of shrubby caudiciforms and large trees, some pachycaul and with thorns. They are found from the Southern USA to Argentina, Hawaii, and in tropical and sub-tropical countries worldwide including Africa and Asia. The ability of the seed of Erythrina fusca (sea beans) to remain viable in seawater probably explains its distribution in both Old World and New World countries.
 
As legumes, these plants and trees host nitrogen-fixing bacteria in root nodules. Many species have bright red or orange nectar-rich flowers followed by pods of seeds. Both nectar and seeds sustain many species of bird. However, the seeds of many species contain toxic alkaloids and should not be eaten by mammals. Despite this, several species are considered to have medicinal properties.

Erythrina crista-galli

Erythrina crista-galli  Linnaeus 1767 (Cockspur Coral Tree, Ceibo)
A flowering drought-tolerant deciduous tree up to 30ft tall. The stout trunk has many irregular branches. The trunk, branches and the underside of the leaves are covered in sharp, curved spines. The taproot has nodules hosting symbiotic Nitrogen-fixing bacteria. The inflorescence is a spectacular raceme of bright red flowers which are attractive to humming birds and bees.
 
Native to Bolivia, Brazil, Argentina, Paraguay and Uruguay. Widely used as an ornamental in warm climates where it may be invasive. An interesting decorative tree for a conservatory or tropical garden and said to be half-hardy, especially in a sunny, sheltered corner. All parts, especially the seeds are toxic, but are traditionally used as a sedative. This is the national flower of Argentina and Uruguay.

Erythrina herbacea Erythrina herbacea

Erythrina herbacea  Linnaeus 1753 (Cardinal Spear, Cherokee Bean)
A flowering succulent shrub from Northern Mexico and the South Eastern USA. Herbaceous stems arise from a woody base and typically die back to the base in Winter. In frost-free areas, the stems grow taller and become woody. The showy spikes of tubular red flowers are attractive to humming birds and are followed by black pods of toxic red seeds. The compound leaves with three pointed leaflets and thorned petioles, are usually produced after the flowers.
 
An interesting plant for a collector of caudicifoms or bonsai and a decorative plant for a tropical garden. All parts contain poisons that cause paralysis in mammals.

Erythrina humeana Erythrina humeana Erythrina humeana

Erythrina humeana  Sprengel 1826 Syn. Erythrina princeps (Natal Coral Tree, Dwarf Kaffirboom) Named for: Sir Abraham Hume
 
This species makes a small tree up to 15 ft tall. Leaves and stems are furnished with prickles to a variable extent. The showy spikes of tubular scarlet flowers appear in the Autumn and are followed by black pods containing scarlet seeds. Plants grown from seed develop a swollen pachycaul base to the trunk.

Native to an area from Mozabique to Eastern South Africa where the flowers are visited by sunbirds. Cuttings root easily but may not develop a pachycaul base. Tolerates mild frost. If the wood is damaged, the plant can resprout from its swollen, succulent, tuberous roots.