1646 



INDIGOFERA 



INDIGOFERA 



but it is also made from the West Indian species, 7. 

 Anil. These species were early introduced into the 

 southern states for indigo-making, and the product was 

 once manufactured to a considerable extent. The plant 

 was introduced into South Carolina in 1742 from the 

 West Indies. When it was found that commercial indigo 

 could be produced, the British Government offered a 

 bounty. In 1775, the production was more than one 

 million pounds of indigo. The war for independence 



1957. Indigof era Kirilowii. (X 3 /s) 



checked the industry, and thereafter the rising impor- 

 tance of the cotton crop, amongst other things, drove 

 it to the wall. But as late as the middle of the last 

 century, indigo continued to be made in remote places. 

 Plants still persist in some places as escapes from cul- 

 tivation. 7. tinctoria is perennial, but is grown from 

 seeds, which give from two to four cuttings of herbage 

 the first year. The indigo is not contained in the plant, 

 but the dye is a product of manufacture from a gluco- 

 side indican which is contained in the herbage, and 

 which is obtained as an extract. Indigo seed is offered 

 by seedsmen. Other species, even of other genera, also 

 yield indigo. Very much of the indigo of commerce is 

 now manufactured synthetically from coal-tar. 



In North America, several species of Indigofera are 

 occasionally grown as ornamental subjects. In the 

 North, they are mostly greenhouse subjects. Propa- 

 gated by seeds or cuttings, chiefly the latter. Recent 

 introductions are 7. amblyantha and 7. Kirilowii, excel- 

 lent species and hardy at the Arnold Arboretum. 



A. Raceme longer than the If. 



decora, Lindl. Weak-growing or even half-climb- 

 ing shrub, the branches slender and red-tinged: Ifts. 

 in 6-8 pairs, broad-lanceolate, usually drooping, sharp- 

 pointed: racemes long, with showy rose-pink fls. about 

 1 in. long; standard oblong, nearly or quite obtuse, 

 with a heart-like mark near the base; wings linear- 



lanceolate or spatulate, ciliate. China. B.R. 32:22 

 B.M. 5063. G.M. 31:591. P.M. 16:290. Regarded 

 as a greenhouse plant and cult, in the open far S. Var. 

 alba (Fig. 1956), with white fls., is a hardy herbaceous 

 or half-shrubby plant at the Arnold Arboretum, Bos- 

 ton. G.F. 7, pp. 266, 376; fig. 61, p. 375 (adapted in 

 Fig. 1956). 



macrostachys, Vent. Shrubby, the sts. terete and 

 appressed-pubescent: Ifts. 8-10 pairs, oval-oblong, 

 obtuse but mucronate, pubescent: racemes longer than 

 the Ivs., many-fld.; fls. rose. China. V.F. 53. 



caroliniana, Walt. Tall and branching, 6-7 ft.: Ifts. 

 4^8 pairs, oblong, oval or oblanceolate, mucronate, with 

 slender petiolules: fls. small, many, yellowish brown 

 and with short-acute calyx-teeth: legume oblong, 2- 

 seeded, less than %in. long. Perennial, in the pine- 

 barrens from N. C. south. 



Kirilowii, Maxim. Fig. 1957. A beautiful species of 

 recent intro., with fls. as large as those of Robinia 

 Pseudacacia, bright rose-color: Ivs. petioled: subshrub, 

 3-4 ft., soon glabrous, the branches slightly angular and 

 bark soon striate: If .-blade to 5 in. long, the stalk to 

 1J^ in.; Ifts. about 7-9, usually opposite, elliptic or 

 rounded-elliptic, obtuse and mucronate, to 1J4 in- 

 long and 1 in. wide, both surfaces bearing white hairs 

 attached by their centers: racemes axillary, longer than 

 the Ivs., the peduncle about twice as long as the 

 petiole; corolla glabrous nearly throughout when in 

 bud; standard oblong-elliptic, %in. long and half as 

 wide, ciliate; keel acuminate, ciliate, as long as stand- 

 ard; anthers prominently apiculate. N. China, Korea. 

 B.M. 8580. M.D.G. 1912:271 Prop, by division, 

 suckers and cuttings; appears not to seed in cult. 



AA. Raceme mostly shorter than, or not exceeding, the If. 



amblyantha, Craib. Upright shrub, 3-6 ft.: young 

 branchlets angled, whitish from appressed hairs: Ivs. 

 petioled, 4-6 in. long; Ifts. usually opposite, oval to 

 elliptic-oblong, broadly cuneate at the base, rounded 

 and mucronate at the apex, bright green above, glauces- 

 cent beneath, appressed-pubescent on both sides, y%- 

 1^2 in. long: fls. in axillary slender racemes with the 

 peduncle 2)^-4 in. long, very numerous, pink, small, 

 M m - long; petals narrow, of nearly equal length; 

 standard spatulate-obovate, upright, incurved at the 

 apex; calyx appressed-pubescent; ovary densely whitish 

 pubescent: pod linear, with both sutures thickened, 

 pubescent, l%-2 in. long. July-Oct. Cent. China. 

 A handsome shrub with its numerous dense racemes of 

 small pink flowers blooming all summer and autumn. 

 Hardy at Arnold Arboretum. Prop, by cuttings, and 

 by seeds which are freely produced. 



australis, Willd. (7. angulata, Lindl. 7. sylvdtica, 

 Sieb.). A very variable species, known by its glabrous 

 aspect, short or nearly obsolete teeth of the calyx and 

 the pod glabrous when young. Erect shrub: Ifts. 9-17, 

 varying from oblong to almost orbicular, %in. or less 

 long, obtuse or retuse: fls. red and mostly showy, the 

 racemes sometimes fully as long as the Ivs.; standard 

 truncate at the base with a very short claw : pod nearly 

 or quite straight, terete. Austral. B.M. 3000. B.R. 

 386; 991. L.B.C. 2:149. 



tinctdria, Linn. INDIGO. Fig. 1958. Shrub, 4-6 ft., 

 with silvery branches: Ifts. 7-15, thin, rather large, 

 obovate-oblong, pubescent beneath: fls. small, reddish 

 yellow, in short racemes, the pedicels finally recurved ; 

 calyx pubescent, the lobes subulate : pod nearly straight, 

 somewhat knotty, 8-12-seeded, about % or 1 in. long. 

 S. Asia. Long cult, and widely distributed. Runs 

 wild S. Indigo was known to the Egyptians. 



Anil, Linn. WEST INDIAN INDIGO. Fig. 1958. Much 

 like the last, but fls. smaller, and pods curved and not 

 knotty, and about ^in. long. W. Indies, but now runs 

 wild in the southern states. B.M. 6506. 



