Botany · Ch 5 — Taxonomy and Systematic Botany
Family: Fabaceae (Pea family)
Family: Fabaceae (Pea family)
Fabaceae (Pea family) includes about 741 genera and more than 20,200 species, cosmopolitan but most abundant in tropical/subtropical regions. Habit ranges across herbs (Indigofera, Crotalaria), shrubs (Cajanus cajan), small trees (Sesbania), climbers (Clitoria), large trees (Pongamia, Dalbergia, Erythrina, Butea), woody climbers (Mucuna) and even a hydrophyte, Aeschynomene aspera (the 'pith plant'). Root: a tap root system, nodulated with tubercles housing nitrogen-fixing Rhizobium leguminosarum. Leaf: simple, unifoliate, bifoliate or trifoliate, alternate, stipulate, with reticulate venation; the terminal leaflet modifies into a tendril in Pisum sativum. Flower: bracteate, bracteolate, pedicellate, heterochlamydeous, complete, bisexual, pentamerous, zygomorphic, hypogynous (occasionally perigynous). Calyx: 5 sepals, synsepalous, valvate/imbricate, odd sepal anterior. Corolla: 5 apopetalous petals forming the characteristic papilionaceous shape - the large outer 'standard' (vexillum), two lateral 'wing' petals (alae), and two anterior petals fused into the 'keel' (carina) enclosing the stamens and pistil - with descendingly imbricate/vexillary aestivation. Androecium: 10 stamens, diadelphous, usually (9)+1 as in Clitoria ternatea (though Aeschynomene aspera shows a dimorphic (5)+5 monadelphous arrangement instead). Gynoecium: monocarpellary, unilocular, superior ovary, marginal placentation, simple bent style. Fruit: typically a legume (Pisum sativum), occasionally indehiscent or a lomentum (Desmodium); in Arachis hypogea the fruit is geocarpic - the fertilised ovary's stipe grows down into the soil to mature underground. Seed: endospermic or non-endospermic, mostly reniform.
Clitoria ternatea (Sangu pushpam) - a twining climber with a branched, nodulated tap root - has flowers with floral formula Br.,Brl.,%, ,K(5),C5,A(9)+1,G1. Pisum sativum (pea) - a cultivated, becoming-shrubby herb - has the identical floral formula, reflecting the same family-defining papilionaceous plan. …
| APG classification | Bentham and Hooker classification |
|---|---|
| Kingdom: Plantae | Kingdom: Plantae |
| Clade: Angiosperms | Class: Dicotyledonae |
| Clade: Eudicots | Sub-class: Polypetalae |
| Clade: Rosids | Series: Calyciflorae |
What this figure shows. A labelled multi-panel botanical plate of Clitoria ternatea: the plant's Habit (a twining climber); an L.S. of the flower showing calyx, standard petal, wing petal, keel petal, stigma, style, ovary and stipe; the Androecium (a single stamen with filament and anther, and the diadelphous bundle); the Gynoecium (stigma, style, stipe, ovary); a C.S. of the ovary showing the ovule and locule; the Floral diagram; and …
What this figure shows. A labelled botanical plate of Pisum sativum (pea): Habit showing the compound trifoliate leaf with a tendril; the entire flower and its L.S. with calyx, corolla (standard, wing and keel petals), stamen and gynoecium (stigma, style, ovary, stipe) labelled; the Androecium (single stamen, filament, anther); a C.S. of the ovary showing the swollen placenta and ovule; the Floral diagram; and …
| Economic importance | Binomial | Useful part | Uses |
|---|---|---|---|
| Pulses | Cicer arietinum (chick pea), Vigna mungo (black gram), Vigna radiata (green gram) | Seeds | Sources of protein and starch of our food |
| Oil plant | Arachis hypogea (Ground nut) | Seeds | Oil extracted from the seeds is edible and used for cooking |
| Timber plant | Dalbergia latifolia (rose wood), Pterocarpus santalinus (red sandalwood) | Timber | Used for making furniture, cabinet articles and as building materials |
| Medicinal plant | Glycirrhiza glabra (Licorice root), Mucuna pruriens | Roots, Seeds | Used in leprosy and leucoderma; neurological remedy |
| Dye plant | Indigofera tinctoria (Avuri) | Leaves | Indigo dye obtained from leaves is used to colour printing and in paints |