Ayurveda consist of two words ‘Ayur’ and ‘Veda’. It is a Sanskrit term and it literally means the science of life (Sharma, 1979). The scope of Ayurveda is vast. It not only deals with the prevention of disease and promotion of health and longevity but it also cures the disease. It also deals with rejuvenation. It can also be called the science of living and it is upveda of Atharva veda. It treats an individual as a whole and not only the symptoms or the affected parts, unlike modern medicines. India due to its unique variety of geographical and climatic factors had a rich and varied flora of medicinal plants. No wonder that out of a total number of over 15,000 plant species in India, about 2000 are known to have medicinal properties and some of them are used even as home remedies in the rural and remotest parts of our country (Arora, 1985). According to Sushruta, no plant in this world is useless. A large number of crude drugs used in Ayurvedic system employ plants of family Fabaceae. The family Fabaceae popularly known as legumes, is the third largest order of seed-plants containing about 600 genera with 12,000 speices. They are usually arranged in three well defined sub families and they are Papilionaceae, Caesalpiniaceae and Mimosaceae. The members of sub family Papilionaceae are herbs, shrubs or trees found in all climates but mostly between and near the tropics and are more abundant in the old than in the New World. The family includes the greatest number of Legumes, comparising 400 genera with about 7000 species. It is an extremely important family and its members yield nutritious food, fiber, shelter, valuable medicines and also virulent poisons (Datta and Kumar , 1985). The members exhibit most varied properties, some are amylaceous, other oleaginous, many yield resins, balsams and dyes, a few are astringent, acrid and bitter, narcotic and poisonous, emetic and purging, tonic and restorative . The seeds are often anti periodic and the root anthelmentic. The term pharmacognosy derived from Greek, pharmakon, a drug, and gignosco, to acquire knowledge of. Pharmacogonasy is mainly concerned with naturally occurring substances having a medicinal action. It also includes the study of other material used in pharmacy such as flavouring and suspending agents, disintegrants, filtering and support media and so on. It is closely related to both botany and plant chemistry. Pharmacognosy has been generally pursued for utilitarian ends and may thus be called an applied science. It has played an important role in the development of the pure sciences, e.g. in descriptive botany, plant classification (taxonomy) and plant chemistry (phytochemistry). Chemical plant taxonomy, genetical studies, involving secondary metabolites are now attracting the attention of more and more botanist and chemists. Review of literature: National: Cassia fistula belonging to Leguminosae family, is widely used for its medicinal properties, its main property being that of a mild laxative suitable for children and pregnant women. It is also a purgative due to the wax aloin and a tonic (Satyavati and Sharma, 1989) and has been reported to treat many other intestinal disorders like healing ulcers (Biswas et al., 1973; Kirtikar and Basu, 1975). The plant has a high therapeutic value and it exerts an antipyretic and analgesic effect (Patel et al., 1965). Besides, it has been found to exhibit antinflammatory and hypoglycaemic activity (Datta and Kumar, 1985). In the Indian literature, this plant has been described to be useful against skin diseases, liver troubles, tuberculous glands and its use in the treatment of haematemesis, pruritus, leucoderm and diabetes has been suggested (Alam et al., 1990; Asolkar et al., 1992). C. fistula extract is used as an anti-periodic agent and in the treatment of rheumatism (Biswas et al., 1973; Kirtikar and Basu, 1975) and the leaf extract is also indicated for its anti-tussive and wound healing properties. Some of the important genera are Abrus sp., Alhagi sp., Arachis sp., Butea sp., Cajanus sp., Cicer sp., Derris sp., Glycine sp., Glycyrrhiza sp., Medicago sp., Pisum sp., Phaselous sp., Psoralea sp., Sesbania sp., Tephrosia sp., Vicia sp. and Vigna sp.. The members of sub family Caesalpiniaceae are trees, shrubs or rarely herbs numerous in the Tropics. They scarcely extend beyond the tropical belt in the old world and they are rather few in North America. The sub family includes 56 genera with about 650 species. The members exhibit mostly tonic, astringent and mucilaginous properties, some have a pectoral and laxative or cathartic action; others are anthelmintic antiseptic , antipyretic, styptic. Some of the important genera are Bauhinia sp., Cassia sp., Cynometra sp. Cassia senna :- It is known by different names in Hindi : Bhuikhakhasa, Hindisana and Sonamukhi ; English : Alexandrian, Bombay, or Tinnevelly senna ; Sanskrit : Bhumiari, Pitapushpi, Swarnamukhi, swarnapatrika ; Rajasthan : Senna. The Senna leaves and pods contain sennasoides A, B, C, D, G, rhein, aloe-amine, Kaempferein and iso-rhein in the free and compound glycoside forms (Srivastava et al., 1982, 1983). The leaves, pods and roots of Cassia senna contains rhein, chrysophenol, imodin and aloe-imodin ( Srivastava et al., 1980). Cassia occidentalis Linn. It is known by different names. In Hindi ; Badikanodi, Chakunda, Kasonda, in English ; Coffee-senna, Foetid Cassia, Negro coffee, Rubbish Cassia, Stinking-weed, in Sanskrit:- Kasamarda and in Rajasthan, Chakundra Talka. All parts of the plant have almost similar properties. They possess purgative, tonic, febrifugal, expectorant and diuretic properties. The plant is used to cure sore eyes, haematuria, rheumatism, typhoid, asthama and disorders of haemoglobin, is also reported to cure leprosy. A decoction of the plant is used in hysteria, in dysentery and other stomach troubles, and also as an application to sores, itch and inflammation of the rectum. The plant is employed in dropsy, and as a vermifuge. Cassia fistula is a fast-growing, medium-sized, deciduous tree which grows to about 9 meters in height. Leaves are compound, with 4-8 pairs of opposite leaflets. It produces flowers which are golden yellow and hang in showering bunches of up to 40 cm long earning its common name of "golden shower tree." The flowers appear when the branches are bare, just before the new leaves emerge and are a favorite of bees and butterflies. The blooms are followed by the production of two-foot-long, dark brown, cylindrical, woody seed pods which persist on the tree throughout the winter before falling to litter the ground. Canafistula is native to India, the Amazon and Sri Lanka, and is now widely cultivated worldwide as an ornamental tree for its beautiful showy yellow flowers. There are many Cassia species worldwide which are used in herbal medicine systems. This particular family of plants are used widely for their laxative actions. Canafistula is no exception... it is often used as a highly effective moderate laxative that is safe even for children. However, in large doses, the leaves and bark can cause vomiting, nausea, abdominal pain and cramps. Canafistula is also employed as a remedy for tumors of the abdomen, glands, liver, stomach, and throat, for burns, cancer, constipation, convulsions, delirium, diarrhea, dysuria, epilepsy, gravel, hematuria, pimples, and glandular tumors. In Ayurvedic medicine systems, the seeds are attributed with antibilious, aperitif, carminative, and laxative properties while the the root is used for adenopathy, burning sensations, leprosy, skin diseases, syphilis, and tubercular glands. The leaves are employed there for erysipelas, malaria, rheumatism, and ulcers. In Brazilian herbal medicine, the seeds are used as a laxative and the leaves and/or bark is used for pain and inflammation. Cassia fistula’s laxative actions come from a group of well documented compounds called anthraquinones that are found in all Cassia and Senna plants in varying degrees. The seeds contain approximately 2% anthraquinones, 24% crude protein, 4.5% crude fat, 6.5% crude fiber, and 50% carbohydrates. The leaves have been documented with 15.88% crude protein, 6.65% crude fat, 20% crude fiber, and 39.86% carbohydrates. In addition to the anthraquinone glycosides, other compounds documented in the plant include fistulic acid, rhein, rheinglucoside, galactomannan, sennosides A and B, tannin, phlobaphenes, oxyanthraquinone substances, emodin, chrysophanic acid, fistuacacidin, barbaloin, lupeol, beta-sitosterol, and hexacosanol .