Indigofera.] XXXI. LEGUMINOS^. 135 



compressed, generally filled with a dry spongy mass -which separates the 

 seeds. 



Calyx-teeth lanceolate, as long as the cup-shaped calyx-tube. 



Leaflets 6-15 pair ; pods spreading 1. / heterantlia. 



Leaflets 4-6 pair ; pods deflexed 2. /. Hnctoria. 



Calyx-teeth triangular, shorter than the oampauulate calyx- 

 tube ; leaflets 4-6 pair ; pods spreading . . . . 3. /. airopurpurea. 



1. I. heterantha, Wall. — Syn. /. polyphylla, Edgeworth. Vern. 

 Khenti, hathi, Ttathu, kati, kathewat, mattu, kasTcei, kiltz, kuts, katsu, shd- 

 gali, Pb. 



A shrub, strigose -with grey adpressed hairs. Leaves imparipinnate, 

 common petiole 1^-2| in. long. Leaflets opposite, 6-15 pair, oblong, or 

 elliptic-oblong, mucronate, less than ^ in. long. Stipules subulate, decid- 

 uous. Eacemes short-pedunculate, as long as leaves ; bracts subulate, 

 deciduous. C^lyx cup-shaped, the teeth longer than, or as long as, tube. 

 Pod spreading, straight cyliudric, 1^ in. long, shining, with a few scat- 

 tered hairs. 



Common in the outer North- West Himalaya, and on the eastern skirts of the 

 Suhman range, ascending to 8000 ft. PI. May, June. In Kashmir and else- 

 where the twigs are largely used for basket-work, and in some cases they form 

 part of the twig-bridges. /. Gerardiana, Wall., with larger flowers and a less 

 number of leaflets, is probably only a variety of this species. 



2. I. tinctoria, Linn. ; Eoxb. Fl. Ind. iii. 379 j W. & A. Prodr. 202 ; 

 Wight Ic. t. 365. The Indigo plant. — Sans. Nili. Vern. Nil. 



Branches, inflorescence, and leaves thinly silky. Leaves imparipinnate ; 

 common petioles 3-4 in. long, fiim, erect ; stipules small, setaceous ; 

 leaflets 4-6 pair, opposite, on short petiolules, oblong or obovate, J-f in. 

 long, turning black when dried. Eacemes axillary, lax, with about 20 

 greenish rose-coloured flowers, at first shorter than, and ultimately equal- 

 ling, the leaves. Pedicel shorter than the silvery calyx; calyx -teeth 

 lanceolate, reaching half-way down. Pods deflexed, l-l|- in. long, thick, 

 nearly cylindrical, straight or nearly so, glabrous when mature, 8-12-seeded. 



Cultivated in the southern and eastern Panjab, ascending on the Chenab to 

 2000 ft. Bare in the Peshawar valley. Grown extensively in Bengal, Sindh, 

 and South India. Cultivated in tropical Africa and America. Wild in Sene- 

 gambia. 



A pereimial undershnib, but generally grown in India from seed as an annual 

 or biennial plant. The stems are cut when in blossom or before they come into 

 flower, steeped in water, and under the influence of fermentation and free access 

 of air Indigo is formed. The juice of the fresh plant does not contain Indigo ready 

 formed, but a colourless substance, the nattire of which is not yet accurately 

 known, and which is converted into Indigo during the process of manufacture 

 in the Indigo vats. Dioscorides and Phnius mention Indigo as a dye used in 

 Egypt and India ; its general use in Europe dates from the sixteenth century. 

 Indigo may be obtained in small quantities from other plants — Isatis (Crucifersej, 

 Europe, Wrightia tinctoria and Marsdenia tinctoria, both included in this 

 Flora, Polygoniim tinctorium (Polygonese), China, and others. 



Nearly allied are two other species, which likewise yield Indigo : 1. 7. Anil, 

 Linn., with racemes shorter than leaves, and sickle-shaped pods. Cultivated 



