440 CONTRIBUTIONS FROM THE NATIONAL, HERBARIUM. 



A specimen from Durango is very closely related, differing only in having 

 the leaflets thinly strigose on the upper surface. 



7. Indigofera sphinctosperma Standi. Contr. U. S. Nat. Herb. 20: 216. 1919. 

 Veracruz ; type from Zacuapan. 



Slender shrub; leaflets about 17, oval or rounded-oval. 8 to 14 mm. long; 

 fruit 3 to 4 nun. long. 



8. Indigofera jaliscensis Rose, Contr. U. S. Nat. Herb. 8: 310. 1905. 

 Jalisco to Morelos ; type from Rio Blanco, Jalisco. 



Shrub, a meter high or less; leaflets about 25, oblong or oval-oblong, 1 to 

 2.5 cm. long. 



9. Indigofera montana Rose, Contr. U. S. Nat. Herb. » 311. 1905. 



Durango, Zacatecas, and Jalisco ; type collected between Mezquite and Monte 

 Escobedo, Jalisco. 



Slender shrub, about a meter high; leaflets oblong or narrowly oblong, 1 to 

 2.5 cm. long ; flowers brown-sericeous. 



Closely related to the preceding species, but usually with narrower leaflets. 



10. Indigofera tumidula Rose. Contr. U. S. Nat. Herb. 12: 273. 1909. 

 Known only from the type locality, Iguala Canyon, Guerrero. 



Shrub ; leaflets oblong, 3 to 4 cm. long, rounded at apex ; fruit 4 to 5 mm. 

 long. 



11. Indigofera mucronata Spreng. ; DC. Prodr. 2: 227. 1825. 



Galega frutescens I\Iill. Gard. Diet. ed. 8. Galcga no. 3. 1768. Not Indigofera 

 friitescens L. f. 1781. 



Indigofera torulosa Hook. & Arn. Bot. Beechey Voy. 286. 1836-39. 



Sinaloa to Veracruz and Chiapas. Widely distributed in tropical regions. 



Plants herbaceous or suffrutescent and procumbent, or sometimes shrubby and 

 2 meters high, sparsely strigose; leaflets oblong to broadly oval, 1 to 3 cm. 

 long, bright green ; flowers pinkish or brick-red ; fruit 2.5 to 4 cm. long, tetra- 

 gonous, slender. "Afiilillo " (Tabasco, Rovirojsa). 



12. Indigofera suffruticosa Mill. Gard. Diet. ed. 8. Indigofera no. 2. 1768. 

 Indigofera anil L. Mant. PI. 2 : 272. 1771. 



Indigofera lindhcimeriana Scheele, Linnaea 21: 464. 1848. 



Occurring nearly throughout Mexico. Widely dispersed in tropical America, 

 and adventive in the Old World. 



Shrub, 1 to 2.5 meters high ; leaflets mostly 11 or 13, oblong or oval, 1 to 3 cm. 

 long; flowers small, greenish or yellowish; fruit 1.2 to 1.5 cm. long, falcate. 

 Known generally in Spanish America as "anil"; " choh " (Yueat.ln. Maya); 

 "jiquelite" or "xiquelite" (Onxaea, Chiapas, Central America; from the 

 Nahuatl xiu-quilitl, "turquoise-herb"); " huiquilitl " {Ramirez); "anil Colo- 

 rado" (Tabasco, Rovirosa) ; "anil jiquelite," "anil months" (Oaxaca) ; " jiqui- 

 lete," "jiguilete" (Guatemala); "azul," " azulejo " (Santo Domingo). 



This species was formerly widely cultivated in the warmer parts of America 

 for the extraction of indigo, although an Old World species, /. tinctoria L., was 

 often used also. The latter is the chief .source of the Old World indigo. In the 

 southeastern United States indigo was an important crop in the early part of 

 the nineteenth century. In 1794 about 1,-500,000 pounds were exported to 

 Europe. In southern Mexico, also, it was an important article of export, in 

 Yucatfi-n up to 1885 at least. The blue dye, for which indigo is chiefly valued, 

 was finally largely replaced by coal-tar products, although much natural indigo 

 is still used, having been found superior for some purposes to the artificial 

 dyes. One of the chief reasons for the decline of indigo cultivation in America 

 is the fact that the extraction and handling of the dye is very injurious to the 

 health of those engaged in the work. The process of extraction of the coloring 



