TAXONOMIC REVISION OF THE GENUS CAESALPINIA L. (CAESALPINIACEAE) FOR BANGLADESH

The genus Caesalpinia L. represented by 12 species has been revised for Bangladesh. Dichotomous bracket key has been given for identification of the species. An updated nomenclature, description of the taxa along with illustrations, specimens examined, ecology, notes on distribution and economic importance have been provided. Chromosome number and ethnobotanical information have also been furnished in most cases. Introduction The genus Caesalpinia L. (Caesalpiniaceae) is a pantropical genus of trees, shrubs and prickly climbers comprising of about 150 species distributed throughout the world (Verdcourt 1979). Most of the members of Caesalpinia are economically, medicinally and horticulturally important. Caesalpinia pulcherrima is a popular ornamental plant, equally important for medicine to treat different bronchial diseases including asthma and bronchitis and cholera, diarrhoea, dysentery and liver complaints (Ghani 2002). Caesalpinia bonduc is used as a native medicine in India to relieve colic, fever, hydrocele, diarrhoea and rheumatism (Bor and Raizada 1954). Some species of this genus produce important tannin and dye viz., C. coriaria, C. digyna, C. decapetala and C. sappan (Ali 1973). There has been no taxonomic revision of this important genus in Bangladesh although the genus received much attention in India and Pakistan. Sanjappa (1992) recorded 20 species of Caesalpinia including both wild and cultivated species from India, whereas, Ali (1973) reported only six species from Pakistan. Earlier, Baker (1878) reported 10 species from Indian sub-continent while Prain (1903) recorded six species from the present territory of Bangladesh. A thorough and critical study of a large number of specimens from Bangladesh and detailed literature survey (Heinig 1925, Datta and Mitra 1953, Sinclair 1955, Khan et al. 1996) revealed that the following 12 species of the genus are present in Bangladesh, viz., Caesalpinia bonduc, C. cacalaco, C. coriaria, C. crista, C. cuculata, C. decapetala, C. digyna, C. enneaphylla, C. hymenocarpa, C. pulcherrima, C. sappan and C. tortuosa. The updated nomenclature, important synonyms, detailed taxonomic account, ecology, specimens examined, economic value and worldwide distribution have been furnished under each taxon. A key to species has Corresponding author. 94 KHATUN AND RAHMAN also been given. Chromosome number and ethnobotanical information have been provided wherever available. Illustrations for rare and uncommon species have been given. Caesalpinia L. Sp. Pl. 380: (1753) Trees, shrubs or woody scandent, prickly climbers, rarely unarmed. Stipules present or not, minute to foliaceous, deciduous or persistent. Leaves alternate, bipinnately compound, rachis armed with prickles below the insertion of pinnae and pinnula; leaflets opposite and rarely alternate. Flowers zygomorphic, bisexual or sometimes unisexual, stalked, yellow, red, showy. Inflorescence of axillary to terminal or supra-axillary, panicled racemes. Bracts mostly deciduous, bracteoles absent. Hypanthium usually obliquely short-cupular or funnel shaped. Sepals 5, free or connate at the base, unequal, imbricate or valvate, the lowest one largest and cucullate, clasping the others, often reflexed during anthesis. Petals 5, free, unequal, spathulate, spreading, usually orbicular with a distinct claw, the standard petal differing in shape and size with a liguliform appendage. Stamens 10, free, delicate; filaments hairy; anthers oblong, uniform, versatile, dorsifixed, split longitudinally. Ovary sessile to sub-sessile; style filliform; stigma terminal, oblique. Pods very variable, oblong, ligulate, thin and flat or thick and subturgid, smooth or spiny. Seeds orbicular to oblong, globose or flat, usually exalbuminous.


Introduction
The genus Caesalpinia L. (Caesalpiniaceae) is a pantropical genus of trees, shrubs and prickly climbers comprising of about 150 species distributed throughout the world (Verdcourt 1979).Most of the members of Caesalpinia are economically, medicinally and horticulturally important.Caesalpinia pulcherrima is a popular ornamental plant, equally important for medicine to treat different bronchial diseases including asthma and bronchitis and cholera, diarrhoea, dysentery and liver complaints (Ghani 2002).Caesalpinia bonduc is used as a native medicine in India to relieve colic, fever, hydrocele, diarrhoea and rheumatism (Bor and Raizada 1954).Some species of this genus produce important tannin and dye viz., C. coriaria, C. digyna, C. decapetala and C. sappan (Ali 1973).
There has been no taxonomic revision of this important genus in Bangladesh although the genus received much attention in India and Pakistan.Sanjappa (1992) recorded 20 species of Caesalpinia including both wild and cultivated species from India, whereas, Ali (1973) reported only six species from Pakistan.Earlier, Baker (1878) reported 10 species from Indian sub-continent while Prain (1903) recorded six species from the present territory of Bangladesh.A thorough and critical study of a large number of specimens from Bangladesh and detailed literature survey (Heinig 1925, Datta and Mitra 1953, Sinclair 1955, Khan et al. 1996) revealed that the following 12 species of the genus are present in Bangladesh, viz., Caesalpinia bonduc, C. cacalaco, C. coriaria, C. crista, C. cuculata, C. decapetala, C. digyna, C. enneaphylla, C. hymenocarpa, C. pulcherrima, C. sappan and C. tortuosa.The updated nomenclature, important synonyms, detailed taxonomic account, ecology, specimens examined, economic value and worldwide distribution have been furnished under each taxon.A key to species has also been given.Chromosome number and ethnobotanical information have been provided wherever available.Illustrations for rare and uncommon species have been given.
Ecology : Grows in coastal areas, inland in scrub jungle, hedges of the crop fields, roadsides, ditches and sometimes forming thickets on vacant lots as ruderal habitat.
Economic importance: The nuts and root bark are considered to be tonic, antiperiodic and febrifuge.The leaves and seeds are much used as native medicine to relieve colic, fever, hydrocele, diarrhoea and rheumatism.The seeds are also used as an anthelmintic, vermifuge, chewed for coughs and eaten for stomach trouble as well as for curing gout (Kanjilal et al. 1938, Bor andRaizada 1954).

Ethnobotanical information:
The villagers use this plant as an effective hedge plant to protect the crop fields in the northern districts of Bangladesh.The leaves are used as emmenagogue in Indo-China (Caius 1989).Powered seeds are administered to cure malarial fever and also used as anthelmintic in Sundarbans region of India (Tribedi et al. 1993).
Ecology: In plains, sunny and dry areas.
Economic importance: This species is used as an ornamental plant for its delicate foliage and profusely display of yellow flowers.
Ecology: Sunny and dry places up to 700 m elevation and even in poor soil.Economic importance: It is suitable for planting in small avenue and large parks due to its dark green foliage with umbrella shaped-canopy for shade and brilliant greenish yellow, scented flowers.This is important for chemical products, medicine and timber (Kumar and Sane 2003).The timber is hard and very heavy.The barks and the pods are considered as astringent.
Ethnobotanical information: In India, the bark is applied for treatment of chronic fever and the decoction of powdered pods are used for washing the bleeding piles.In Southern part of India the pod is used as a source of powerful tanning, which is used to make ink.In Mexico, a black dye is extracted (Bor andRaizada 1954, Caius 1989).
Ecology: In village thickets, along streams, river banks, mangrove forest and its fringes, coastal areas along seashore and on sandy beaches.

Economic importance:
The root is considered as diuretic.Roasted seeds, root and the juice of the stem are applied both externally and internally for treatment of eye diseases (Bor and Raizada 1954).
Ethnobotanical information: In India, the plant is used as the host of 'lac insect' and the finely powdered form of leaves is administered to women as a tonic just after delivery (Caius 1989).
Ecology : Sunny and dry habitats in bushy open places, in hedges and river banks.
Specimens examined: Kushtia : Chuadanga, Kalabari, 2. 1.1976, Huq, Rahman & Mia, H 1833;Chuadanga, A.M. Huq, H 4692. Economic importance: The plant is medicinally important and different chemical products are obtained from this species (Kumar and Sane 2003).It is cultivated for excellent hedge plant and suitable for gardening for its bright yellow flowers in large racemes.The root is used as purgative.The plant is also used as the host of 'lac insect' (Ali 1973).
Ethnobotanical information : In South India the bark of the plant is reported as a source of tanning material (Ali 1973).The tribal people of Naga in India use this plant as their village defense.The branches of the plant were erected on the forked poles over the paths during the day while at night the poles were removed and the plant laid on the ground as creeper, forming impenetrable barrier to any miscreant (Bor and Raizada 1954).
Ecology : In clearings, thickets, forest fringes, sometimes at the slop of the hills, and open and dry places.

Ethnobotanical information:
In some part of Myanmar, the pounded root is mixed with water to make a drink which is used as febrifuge (Caius 1989).The pods are considered as the source of tanning material (Kanjilal et al. 1938).
Ecology : In dry hill slopes, secondary forests and open sunny places.
Ecology : In secondary growth, hilly, monsoon forests, scrub jungles and river banks.Economic importance : It is used as an ornamental and hedge plant.

Ethnobotanical information:
The plant is used as the host of 'lac insects'and the bark is the source of tanning material in South India (Bor and Raizada 1954).
Ecology : Dry and sunny places, generally in gardens, parks and homesteads.
Specimens examined: Chittagong : Sitakund, Huq & Mia, H 8052. Dhaka : Green Road, 18.03.1978, Huq et al., H 3878;Sahrawardy Uddan, 14.5.1980, Momtaz Begum 375. Mymensingh : Mymensingh, 2001, Sakir Hossain, No. 13;Sylhet : Jafflong, 20.10.1986, Huq & Mia, H 7910. Economic importance: It is planted as a popular ornamental plant.The leaves, flowers and seeds are largely used in Indian medicine.The pounded root is useful in infantile convulsions.The infusion of the flowers are used as a remedy of cough, chronic catarrh, asthma and malarial fever.Leaf juice is administered for treatment of fever (Bor and Raizada 1954).The fruits are main sources of tannin and the flowers yield a red dye (Chakraverty and Jain 1984).
Ethnobotanical information: In Indo-China, the plant is considered as tonic, stimulant and emmenagogue.In the Philippines, the leaves are used as purgative.An infusion of the flowers is used as febrifuge, and is applied for the treatment of bronchitis, asthma, and malarial fever (Caius 1989).
Ecology : In scrub jungles, limestone hills and under cultivation around villages.
Specimens examined: Kushtia : Chuadanga, A.M. Huq, H 4592; Chuadanga, 2. 1.1976, Huq, Rahman & Mia, H 1833. Economic importance : The species is important for wood, chemical products and medicine (Kumar and Sane 2003).The wood is used in decoction form in various diseases especially skin diseases (Caius 1989).It is also used as an ornamental plant.
Economic importance : Wood of this species is used as firewood.