Angiospermic Family – FABACEAE: Pea Family
The Fabaceae, also called Leguminosae or bean and pea family, is the 3rd largest family of angiosperms after Orchidaceae (orchids) and Asteraceae (daisies, sunflowers), and second only to Poaceae (grass) in regards to agricultural and economical importance.
Legumes include a large number of domesticated species gathered as crops for human and animal usage as well as for oils, fiber, fuel, fertilizers, timber, medicinal, chemicals, and horticultural varieties. In addition, the family includes numerous species studied as hereditary and genomic model systems (e.g., pea, Pisum sativum, barrel medic, Medicago truncatula, and trefoil, Lotus corniculatus).
A family of about 400 genera and 9000 species, the members of this family occur all over the world, however, especially in the warm temperate regions. In Pakistan, about 82 genera and about 587 species have actually been reported.
Diagnostic Characters of FABACEAE Family
Habit
Legumes differ in habit from annual and perennial herbs to shrubs, trees, vines/lianas, and even a few aquatics. Ranging in size from a few of the tiniest plants of deserts and arctic/alpine regions to the highest of tropical rain forest trees, legumes are a noticeable, and typically dominant, component of most of the vegetation species distributed throughout temperate and tropical regions of the world. Legumes are especially diverse in tropical forests and temperate shrublands with a seasonally dry or arid climate.
This choice for semi-arid to arid habitats is associated with nitrogen requiring metabolism. While many species have the capability to colonize barren and minimal lands because of their capability to “fix” atmospheric nitrogen by means of a cooperative association with root-nodulating bacteria, this is just one of the numerous methods by which legumes get high levels of nitrogen to fulfill the demands of their metabolism.
The world’s biggest legume fruits (bean pods) are produced by the tropical liana Entada. The longest pods of the Central American E. gigas might be up to 5 feet long (1.5 m). This massive woody vine is truly like Jack’s amazing beanstalk. In Costa Rica, it is called “monkey ladder” or “Escalera de mono.” The woody seeds of E. gigas are called “sea hearts” and are often washed down streams to the sea where they wander throughout the ocean to remote continents. Familiar edible bean pods in the background consist of green beans, peanuts, soybeans, and snow peas.
Vegetative Characters
Roots
Fibrous tap root frequently establishes nodules in herbs. Nitrogen-fixing with bacteria live in these nodules.
Stem: Herbaceous or woody; Cylindrical, tendril climbers.
Leaves: Petiolate; alternate: compound of pinnate type. Stipulate, stipules may be modified into leaves or thrones; parallel venation.
Floral Characters
Inflorescence: Racemose or solitary axillary. Flowers: Bisexual, zygomorphic, bracteate, pedicellate, perigynous, pentamerous, and papilionaceous.
Calyx: 5 sepals, more or less united in a tube, mainly hairy.
Corolla: Papilionaceous; petals 5, generally clawed, different; the upper posterior petal is large and conspicuous and is called basic or vexillum, 2-lateral ones totally free called wings and 2 anterior innermost that fuse to form a boat-shaped structure called the keel or carina.
Androecium: Stamens 10, mainly diadelphous (united by their filaments in 2 groups), 9 fused to form a sheath around the pistil, while the 10th posterior one is totally free.
Gynoecium: A simple pistil, 1- carpeled, with 1-locule; ovary superior; ovary and style long, style bent at is bar,
Placentation (mono carpellary) marginal.
Fruit: Usually a legume or pod, showing a fantastic variety of types in various species.
Seed: Non-endospermic seed.
Floral Formula:
K(5) Co5 or 1+2+(2) S9+1, 10, 10- P1
Economic Importance
- The family is of substantial value as a source of high- protein food, oil, and forage as well as ornamentals and other usages.
- The main importance lies in the pulses, coming from this family, which are utilized as food, some crucial and typical species of pulse yielding plants are Gram, Pea, Kidney bean. These pulses are rich in protein contents.
- Medicago sativa Alfalfa is among the world’s finest forage crops for horses. Vicia, Melilotus, and Trifolium are likewise cultivated as main fodder crops.
- Many trees of this family provide excellent timber for structure, furnishings, and fuel. The main timber plants are Butea, Dalbergia, and so on.
- Seeds of Arachis hypogea peanut are edible and likewise used for extraction of peanut oil which after hydrogenation is utilized as vegetable oil.
- Indigo dyes are obtained from Indigofera tinctoria and Butea monosperma, yielding yellow dye from flowers.
- Many plants of this family are very important for medicines: these include Glycyrrhiza glabra for cough and cold, and Clitoria tematea is used against snake bite.
- The red and white seeds of Abrus precatorious are used by jewelers as weights called “Ratti”.
- Some crucial ornamental plants include Lathyrus, Lupinus, Clitoria, Butea, etc.