Useful information on the characters of the family Fabaceae

Introduction and Systematic Position- Previously Fabaceae was under the family Leguminosae as the sub-family Papilionaceae. Now it has been given to the family rank. So the sub-family Papilionaceae becomes the family Fabaceae.

Systematic Position:

Class – Dicotyledons

Subclass – Polypetalae

Series – Calyciflorae

Order – Leguminates

Family – Fabaceae

Description of the family has been given below.

Habit:

Fabaceae shows a wide variety of habits. They may be herbs, shrubs and trees. Some members are tendril climbers.

Stem:

Herbaceous, weak or woody branched cylindrical or angular.

Leaves:

Alternate and stipulate leafbase is swollen (pulvinus). Leaves are pinnately or palmately compound. In Pisum sativum the upper leaflets are modified to tendril.

Inflorescence:

Raceme or panicle raceme sometimes solitary axillary.

Flowers:

Flowers are bracteates, bracteolate, pedicillate, complete, bisexual, zygomerphic usually Hypogynouis or slightly perigynous.

Calyx:

Usually 5 sepals, gamosepalous, aestivation is valvate or imbricate, odd sepal is anterior.

Corolla:

Usually 5 petals, polypetolous, corolla is papilionaceous. The odd posterior petal is called standard or Vexillum is the largest petal. The two lateral ones, called wing, two innermost are smallest and united to form a boat-shaped structure called Keel.

Androeceium:

Stamens 10, usually diadelphous e.g. 1+ (9), sometimes monadelphous, rarely polyandrous, anthers are dithecous, dorsifixed and introrse.

Gynoecium:

Monocarpellary, ovary superior, unilocular with many ovules at ventral sutures. Placentation is marginal. The style is long stigma capitate.

Fruit:

It is a legume (pod) or lomentum.

(i) Cajanus Cajan (Red gram. Arhar)-One of the main pulses. It is used as a proteinaceous food.

(ii) Arachis hypogeal (Groundnut)-it is one main sources of oil. Seeds of groundnut contain 44 to 50 % oil. Purified oil is used for cooking. The oilcake is used as cattle feed and fertilizer.