1. Diagnostic features :
- Mostly herbs, rarely shrubs or trees, often climbing.
- Leaves alternate, stipulate, simple, or imparipinnately compound.
- Flowers bisexual, zygomorphic, corolla papilionaceous, aestivation descending- imbricate, posterior petals outermost, stamens 10 or 9, monadelphous or diadelphous, rarely free.
- Gynoecium monocarpellary, unilocular with marginal placentation.
- Fruit a legume or pod.
2. Distribution :
- Includes about 482 genera and nearly 7200 species.
- Worldwide in distribution.
- Grow abundantly in tropical, sub-tropical and temperate regions, of both the northern and southern hemispheres.
- Found in plains as well as in hilly regions reaching up to 8000 feet.
3. Vegetative characters:
- Show a wide range of variation in their habit.
- Usually herbs (Vicia, Pisum), shrubs (Cajanus, Ulex) or trees (Butea, Dalbergia).
- Climbers are also most common (Pisum, Lathyrus).
- Branched tap root system.
- Root nodules containing nitrogen fixing bacteria.
- Aerial, usually erect.
- sometimes climbing or twiners.
- branched, cylindrical or angular.
- herbaceous or woody.
- solid or fistular.
- Cauline and ramal, alternate rarely opposite or whorled.
- Stipulate or exstipulate, stipules leaf like (Pisum) simple (Cajanus) or pinnately (Pisum) or palmately (Crotalaria) compound.
- Terminal leaflet modifies into a tendril in Lathyrus, Pisum, Vicia.
- Venation unicostate (Pisum) or multicostate (Crotalaria) reticulate.
4. Floral characters.
- racemose usually a raceme (Pisum, Lathyrus).
- sometimes spikes (Uraria), panicles (Dalbergia), solitary axillary (Cicer) or terminal.
- pedicellate, bracteates. Sometimes bracteolate (Sesbania).
- complete, hermaphrodite, zygomorphic.
- pentamerous, hypogynous or perigynous.
Image source: quora
- sepals-5, gamosepalous.
- persistent, valvate or imbricate.
- odd sepal anterior.
- petals-5, very unequal and papilionaceous (i.e. one posterior petal is very large and called standard, 2 lateral wings and two innermost, smallest united petals known as keel).
- aestivation vexillary or descending imbricate.
- stamens-10, diadelphous usually 9+1 (Pisum) or sometimes 5+5 (Smithia).
- Only 9 monadelphous stamens are present in Dalbergia.
- anthers usually two-celled, introse, basi or dorsi fixed, dehiscing by longitudinal slits.
- In Sophora all the stamens are free.
- carpel one, ovary superior, unilocular, with many ovules in two rows.
- placentation marginal.
- style and stigma simple.
- usually a legume or,
- sometimes indehiscent (Melilotus).
- usually non-endospermic.
- Embryo is large and curved.
i) General floral formula with floral diagram:
5. Economic importance
i) Pulses and vegetables:
- Almost all pulses belong to this family.
- They are sources of protein.
- Examples: Cajanus cajan (arhar- pigeon pea), Cicer arietinum (gram or chana), Pisum sattivum (matar or pea), Dolichos lablab (semi or bean), Glycine max (soyabean or bhattamas), Phaseolus aureus ( mung).
- Dalbergia sissoo, Butea and Pterocarpus provide excellent wood for various building purposes, furnitures and fuel.
- Oil obtained from the seeds of the plants are used for various purposes.
- Some are edible (Arachis hypogea– ground nut, Glycine max– bhattmas), some are used for preparing vegetable ghee (soyabean oil), some (ground nut oil) for preparing soap and cosmetics.
- Oil cake is used as fodder.
iv) Green manuring:
- Crotalaria junceae, Medicago sativa, Trifolium pratense, Sesbania aculenta (Dhaicha), etc are used to increase the nitrogen content of the soil.
- Yellow dye obtained from Butea monosperma.
- Blue dye obtained from the flowers and seeds of Clitoria ternatea.
- Pisum sativum, Lathyrus, Butea, Clitoria, Clianthus dampieri (Glory pea) are used as ornamental plants.
- Crotalaria, Sesbania , etc are used as the source of fibres which is used for making cords, bags and ropes.
- Glycyrrhiza glabra, Clitoria and Teramnus labialis are used as medicines for various diseased condition.
Characteristics and economic importance of family Papilionaceae (Leguminosae)