Indigofera
(from indigo, a blue dye, and fero, to bear; on account of some of the species yielding the well-known dye). Indigo. ORD. Leguminosae. A genus comprising 220 species of stove, greenhouse, or half-hardy herbs, shrubs, or sub-shrubs, the greater number of which belong to the African continent, but abound also in America and Asia, and a few extend to Australia. Flowers usually pink or purple, in axillary racemes or spikes; keel of corolla furnished with a subulate spur on both sides, at length usually bending back elastically. Leaves impari-pinnate or pinnate, rarely digitate or simple. Very few species of this large genus are in cultivation. They are propagated by seeds; or by firm cuttings of young shoots, inserted in sandy or peaty soil, under a hand glass, in a slight heat, in summer. I. decora is a very desirable greenhouse shrub of moderate growth, which flowers profusely in summer, and is one of the species most generally cultivated. The plants should be cut in, about February or March, and started in a little warmth, when any repotting should also be attended to. They may be hardened, to grow in a cold frame afterwards, and watered freely throughout the growing and flowering period. The wood should be thoroughly ripened by exposure, in autumn, and a season of rest allowed in winter. I. Gerardiana forms a compact bush in the open shrubbery, and is also well adapted for covering walls, where it makes better growths, and flowers more freely. It is one of the hardiest species. Indigoferas succeed in a somewhat rough compost of turfy loam and leaf soil. To insure an abundance of flowers, the wood must be well ripened. I. angulata (angular). A synonym of I. australis.
I. Anil. Anil. fl. pinkish; racemes axillary, shorter than the leaves. Summer. l. pinnate, with three to seven pairs of oval or oblong leaflets, hardly pubescent beneath. Stems shrubby, erect. h. 2ft. to 4ft. West Indies and tropical America, previous to 1731. Stove. (B. M. 6506.) I. atro-purpurea (dark purple). fl. dark purple, crimson; racemes axillary, slender. August. l. pinnate, with five to seven or ten pairs of oval, retuse, mucronulate leaflets, rather undulated on margins. h. 5ft. Nepaul, 1816. Half-hardy shrub. (B. M. 3065; B. R. 1744.) I. australis (Southern).* fl. rose-coloured; racemes rather shorter than the leaves. March to June. l. pinnate, having five to seven pairs of elliptic-obtuse, glabrous leaflets. Stem shrubby. h. 3ft. to 4ft. Australia, 1790. A handsome greenhouse species, with a neat habit; it is an excellent pot plant. SYNS. I. angulata (B. R. 991), I. sylvatica (B. M. 3000). (B. R. 386; L. B. C. 149.) I. decora (comely). fl. reddish, disposed in dense racemes. Spring and summer. l. pinnate; leaflets two to six pairs, ovate, obtuse, mucronate, and with a few peltate hairs beneath. h. 3ft. China, 1844. Greenhouse evergreen shrub. (B. M. 5063; B. R. 1846, 22.) I. d. alba (white).* An elegant variety, with long racemes of white flowers; it thrives well, and proves almost hardy, when planted against a wall. I. Dosua (Dosi-swa). fl. bright red; racemes axillary, shorter than the leaves. Summer. l. pinnate, having ten to fifteen pairs of oval, retuse, mucronulate leaflets, which, as well as the branches, are clothed with rufescent hairs on both surfaces. h. 1 1/2ft. India. Greenhouse. I. floribunda (profuse-flowering). A garden name of I. Gerardiana. I. Gerardiana (Gerard's).* fl. pale red, in distinctly-stalked, twelve to twenty-flowered racemes. July. l. shortly stalked, pale grey-green, glaucous and hoary below. India. A low, much-branched shrub, perhaps the hardiest species. SYN. I. floribunda, of gardens. (B. R. 1842, 57, under name of I. Dosua.) I. sylvatica (sylvan). A synonym of I. australis.
I. tinctoria (dyer's).* fl. with a pale vexillum, and red keel and wings; racemes axillary, shorter than the leaves. July. l. pinnate, with four to seven pairs of obovate leaflets, which are pubescent beneath. Stem suffruticose, erect. h. 4ft. to 6ft. East Indies, 1731. Stove. This is the most universally cultivated of all the species.
I. violacea (violet). fl. purple, red; racemes axillary, longer than the leaves. Summer. l. pinnate, with five pairs of obovate-elliptic, flat, slightly pubescent leaflets. h. 5ft. East Indies, 1819. Half-hardy. (B. M. 3348.)