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In this article we will discuss about:- 1. Characters of Caesalpiniaceae 2. Distribution of Caesalpiniaceae 3. Economic Importance 4. Important Types.
Characters of Caesalpiniaceae:
Leaves paripinnate; flowers zygomorphic; calyx and corolla 5, ascending imbricate; stamens 10 or less, free, gynoecium monocarpellary with marginal placentation.
A. Vegetative characters:
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Habit:
It shows great variation in habit i.e. may be trees (Delonix regia, Tamarindus, Caesalpinia, Saraca indica, Cassia fistula, Bauhinia etc.), shrub, undershrubs or herbs. Besides this sometimes all types of plants occur in same genus e.g. Cassia fistula – tree; C: sophera-shrub; C. occidentalis – undershrub and C. tora – annual herb. Bauhinia vahlii is a woody climber.
Root:
Tap and branched.
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Stem:
Erect, woody, herbaceous or climbing, branched, glabrous or covered with prickles and spines (Parkinsonia).
Leaf:
Alternate, leaf base pulvinate, compound unipinnate (Cassia, Tamarindus), bipinnate (Delonix, Caesalpinia) or rarely simple; stipulate. In Bauhinia the leaf is deeply emarginate – perhaps due to the fusion of two leaflets.
B. Floral characters:
Inflorescence:
Racemose.
Flower:
Pedicellate, bracteate, zygomorphic, complete, hermaphrodite, slightly perigynous, pentamerous.
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Calyx:
Sepals 5, free, or connate, odd sepal anterior, imbricate aestivation. In Tamarindus the two posterior sepals are united.
Corolla:
Petals 5, in Tamarindus there are only three posterior petals; in Copaifera saraca the petals are totally reduced; free, ascending imbricate aestivation, posterior petal is innermost.
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Androecium:
Stamens 10, free, reduction in number of stamens by the formation of staminodes. In Cassia there are 3 posterior staminodes; Saraca 3-8 stamens; in Tamarindus only 3 stamens and monadelphous; dithecous, introrse.
Gynoecium:
Monocarpellary, ovary superior or slightly inferior, unilocular with marginal placentation, straight or curved, hairy; style long; stigma simple.
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Fruit:
Legume and never breaks up into one seeded parts.
Seed:
Non-endospermic.
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Pollination:
Entomophilous.
Floral formula:
Distribution of Caesalpiniaceae:
It is commonly called cassia family. The sub-family contains 135 genera which are cosmopolitan in distribution. In India it is represented by 110 species and more than 21 genera.
Economic Importance of Caesalpiniaceae:
1. Food:
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The flower buds of Bauhinia variegata (H. Kachnar) are used as vegetable. The fruits of Tamarindus indica (H. Imli) are spicy and used as condiment.
The seeds of Tamarindus indica yield starch.
2. Medicine:
The pulp of the pods of Cassia fistula (H. Amaltas) is utilised as a purgative. The bark-decoction of Saraca indica (H. Ashoka) is used as a remedy for menstrual disorders.
3. Fibre:
The bark of Bauhinia vahlli yields fibres which are used in rope making.
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4. Dye:
The wood of Haematoxylon campechianum yields a dye called haematoxylin. This is an anatomical stain.
5. Tanning:
The pods of Caesalpinia coriaria, C. sappan and C. digyna are used in tanning leather.
6. Ornamentals:
Delonix regia (syn. Poinciana regia) H – Gulmohar, Bauhinia sp., Caesalpinia pulcherrima, Colvillea racemosa, Parkinsonia aculeata, Saraca indica etc., are grown in gardens and along the road side. Delonix and Saraca are liked for their deep shade giving quality.
Primitive characters:
1. Plants mostly trees and shrubs.
2. Leaves simple {Bauhinia).
3. Flowers hermaphrodite, large and brightly coloured.
4. Stamens polyandrous.
5. Ovules anatropous.
Advanced characters:
1. Leaves compound in most of the genera.
2. Inflorescence simple or compound raceme.
3. Flowers zygomorphic.
4. Calyx gamosepalous.
5. Reduction in number of petals or absent (Dialium, Saraca).
6. Reduction in number of stamens to five or three (Tamarindus).
7. Gynoecium monocarpellary.
8. Seeds non-endospermic.
Common plants of the sub-family:
1. Bauhinia variegata (H. Kachanar):
An ornamental plant with beautiful flowers and bilobed leavs.
2. Caesalpinia pulcherrima (Peacock flower or H. Radhachura):
Cultivated in gardens.
3. Cynometra cauliflora:
It has edible fruits. Oil prepared from its seeds is applied in leprosy and skin diseases.
4. Parkinsonia aculeata (H. Vilayti kikar):
A large shrub or a small tree, with yellow scented flowers.
5. Delonix regia (syn. Poinciana regia) (H. Gulmohur or Krishnachura):
A spreading roadside tree with beautiful foliage and red flowers.
6. Saraca indica (H. Ashoka):
An ornamental tree and supposed to be very sacred because according to Ramayana, Sitaji was kept in captivity in Ashoka Vana (forest of Saraca indica) by Ravana.
7. Tamarindus indica (H. Imli):
A tree with 3 petals and stamens.
Important Type of Caesalpiniaceae:
Cassia fistula, Linn. (Fig. 53.1):
Habit:
A perennial tree.
Root:
Tap, branched and perennial.
Stem:
Erect, cylindrical, woody, solid, branched.
Leaf:
Cauline and ramal, alternate, petiolate, stipulate, stipules minute, caducous; paripinnately compound, leaflets 4-8 pairs.
Leaflets:
Opposite, subsessile with pulvinus at the base, wavy margin, acute apex, glabrous, unicostate reticulate venation.
Inflorescence:
Raceme.
Flower:
Pedicellate, bracteate, complete, hermaphrodite, zygomorphic, pentamerous, hypogynous.
Calyx:
Sepals 5, polysepalous, odd sepal anterior, imbricate aestivation, inferior.
Corolla:
Petals 5, polypetalous, yellow, clawed, ascending imbricate aestivation, inferior.
Androecium:
Stamens 10, in two whorls of 5 each, 3 posterior ones are staminodes, polyandrous, filaments unequal in length, anthers basifixed, dithecous, introrse.
Gynoecium:
Monocarpellary, ovary superior, unilocular, marginal placentation, style short, stigma terminal and hairy.
Floral formula:
