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.

Vegetable drugs are usually arranged for study in one of the following five ways :-

1. Alphabetical : The drugs are arranged in alphabetical order using either Latin or English names .

2. Taxonomic : The drugs are arranged according to the plant from which they are obtained in phyla, orders, families, genera and species.

3. Morphological : Drugs are divided into different groups such as organized drugs which include root, wood, bark, flowers, fruits and leaves and unorganized drugs such as oil, fats, extracts and gums.

Pharmacological or therapeutic : Classification of drugs is according to the pharmacological action of their most important constituent.

4. Chemical : Drugs are classified according to their most important constituent that is alkaloids, volatile oils etc.

Abrus precatorius Linn.

Vernacular Names :- Assam : Latuwani ; Bengal : Chunhati ; Bombay : Ghungchi ; English : Indian liquorice ; Gujrat : Chanoti ; Hindi : Chirmiti, Rati ; Punjab : Labri Ratak ; Sanskrit : chataki ; Tamil : Adisamiyai ; Telgu : Raktika.

Family :- Papilionaceae.

Distribution :- It is found in Ceylon, Pakistan, throughout the tropical regions and it is found throughout India.

Morphology :- A perennial, twinning shrub. Leaves 9-12 cm long, leaves have rachis bristle-tipped ; leaflet 10-20 pairs, 1-2 x 0.5-0.8 cm, oblong. Flowers pink, born in fascicles on swollen nodes of axillary racemes. Calyx campanulate, corolla 8-9 mm long, stamens 9, pods oblong, beaked, pubescent and turgid. Seeds ovate, elliptic, shinning smooth, scarlet red colour with black hilum and 3-8 mm long (Bhandari, 1978).

Chemical composition :- It contains glycyrrhizin and acrid resins (Trease and Evans, 1973).

Part used :- Root, leaves and seeds. (Plate - 1a).

Uses :- Roots of watery extract is useful in relieving cough. The powdered root with ginger and other carminatives is much used for coughs, including whooping –cough. In Ceylon it is taken for sore throat and rheumatism. It is used as a remedy for pain in the chest. Roots are applied to the snake-bitten part. A cold infusion of the root is used in leucorrhoea and for gonorrhoea. In Kyasaland the roots are cooked with beans for urine disease. Emetic, alexiteric, for diarrhea, night blindness, inflammation of gums, gravel or mucous in urine. Leaves are warmed over the fire and applied to painful swellings over which a little amount of castor-oil is smeared. Thus, they are antiphlogistic in their action. Leaves are steeped in warm mustard oil and applied over the seat of pain in rheumatism. Juice of fresh leaves mixed with some oil and applied externally seems to relieve local pains. They are given to relieve hoarseness, eye inflammation (vapours) cancer, syphills, on leucodermic spots (juice). In ivory coast the pounded leaves are applied to eyes in cases of conjunctivitis and an infusion of leaves is taken for colic. It is also used internally for chest complaints and cough. A poultice of macerated leaves are said to have some effect in removing freckles. Seeds are useful in affection of nervous system and externally in skin diseases, ulcers, affections of the hairs. Seeds reduced to paste are applied locally in sciatica stiffness of shoulder joints, paralysis and of nervous disease. In white leprosy seed paste and plumbago root is applied as a stimulant dressing. They are used as purgative. Taken internally by women, the seed disturbs the uterine functions and prevents conception. Powdered seeds are taken as snuff in cases of violent headache arising from cold. Reduced to a paste they are used for contusions and inflammations. After removing their outer coating and powdered with sugar candy they are swallowed to expel intestinal worms. When boiled with milk the seed is said to have a very powerful tonic action in the nervous system. In this form, they are used as an aphrodisiac. The powdered seeds when administered internally uncooked act as a strong purative and emetic. Seeds are also used in treatment of ophthalmia and a cure for malaria.

Alhagi maurorum Linn. ( Javasa )

Family :- Papilionaceae .

Distribution :- It is found in Baluchistan, Egypt, Pakistan, Arabia and in India it is found in Delhi, Gujrat, Maharashtra, Punjab and in Rajasthan.

Morphology :- A small erect shrub, armed with sharp, long spines; branches glabrous or nearly so. Leaves are simple, obovate, apiculate, coriaceous, 6-9 x 4-5 mm, obtuse, glabrous or puberulos, cuneate at base; petioles short. Flowers 5-8 on a spine. Calyx and ovary glabrous. Corolla red and glabrous. Pods falcate, glabrous, constricted between the seeds and 28-30 mm long. Seeds blackish – brown, polished and reniform (Bhandari, 1978).

Part used :- Leaves .

Uses :- Leaves are used in asthama .

Alysicarpus longifolius Wt. and Arn. ( Leel ) ( Papilionaceae )

Vernacular Names :- Gujrat : Dhodasamervo ; Hindi : Leel .

Family :- Papilionaceae.

Distribution :- It is found throughout India.

Morphology :- An erect, stout herb, 1-1.5 m high, stem with glabrous, ascending, terete, slightly striate and with few branches. Leaves unifoliate ; leaflets, oblong or lanceolate, obtuse or sub-acute minutely pubescent on both the surfaces, strongly nerved and closely reticulately veined. Leaf base is rounded or subcordate ; petiolules 2 mm long and hairy. Flowers erect. Calyx 8-9 mm long, striate, ciliate, pubescent, tube funnel-shaped, imbricate in fruiting state. Corolla, yellow colour with keels and wings usually paler with purple tips. Pods terete-compressed, apiculate, 4-6 jointed, downy, shortly stalked, reticulately veined and beak conical, green, downy (Bhandari, 1978).

Part used :- Root.

Uses :- Roots are used in headache.

Alysicarpus vaginalis Linn.

Family :- Papilionaceae.

Distribution :- It is found throughout tropical region of world.

Morphology :- A prostrate, procumbent or diffuse annual herb. Stem upto 8 cm long, slender, tough, pubescent with minute, white spreading hairs as well as long, brown, adpressed, aculate hairs. Leaves unifoliate ; leaflets lanceolate or oblong to broadly ovate, obtuse or rounded at apex, glabrous, pubescent with minute long and aculeate hairs, prominently veined on the lower surface ; petiolules 3-5 mm long and stripped. Stipules 6-9 mm long, lanceolate, ovate, striate, straw coloured and persistent. Flowers in axillary or terminal, 4-12 flowers racemes, along an elongated, densely, pubescent axis, sometimes in pairs ; pedicels 1-15 mm long. Calyx straw coloured, pubescent, 4-5 mm long, prominently nerved, tube 1-3 mm long, flesh coloured and bear narrow teeth. Pod very obscurely monili form, erect on 3-4 mm long stalk, hairy with minute and aculeate hairs and reticulately veined (Bhandari , 1978).

Part used :- Root.

Uses :- Roots are used in local medicines.

Arachis hypogaea Linn. (Peanut)

Vernacular Names :- Bengal : Bilati moong ; Bombay : Bhuichang ; English : peanut, Groundnut ; Gujrat : Bhoimag ; Hindi : Moongphali ; Marathi : Vialyatimug ; Punjab : Mungphali ; Sanskrit : Bhuchamaka ; Tamil : Nilakkodalai ; Telgu : Nilasanagalu.

Family :- Papilionaceae.

Distribution :- It is cultivated throughout America, Africa, India and Brazil.

Morphology :- A low growing annual herb, having height 0.3-0.6 m. Leaves quadrifoliate with two pairs of leaflet on a slender, grooved petiole. Flowers lemon yellow, sessile, borne in the axil of leaves in clusters of 2-4. Fruit is an elongated oblong, indehiscent pod, containing 1-3 seeds. Pod constricted. Seeds ovoid or cylindrical and with brick-red or rust coloured seed coat (Grieve and Leyel, 1959).

Chemical composition :- Arachis oil consist of the glycerides of arachidic, stearic, lignoceric, oleic and other acids (Grieve and Leyel, 1959).

Part used :- Seeds and oil. (Plate – 1b).

Uses :- Unriped seeds are given to women whose supply of milk is insufficient for their children.