safford: cosmos sulphureus 617 



men of which he enclosed in his letter. That the plant in ques- 

 tion could not possibly belong to the genus Tagetes was shown ' 

 at once by the fonii of the involucre subtending the flower-head, ' 

 which according to Hernandez's drawing, was not at all cup- 

 shaped, or tubular like that of Tagetes but composed of several' 

 distinct linear bracts. A comparison of Hernandez's rude illus- 

 tration (fig. 1) with herbarimn specimens of Tagetes showed that . 

 the plant in question could not possibly be included in the same 

 genus with them. His figure represents a composite with flower-- 

 heads not unlike those of a Coreopsis, but the accompanying 

 leaves are artemisia-like as stated in the original description. 

 The widely spread ray-flowers, few in number, are three-toothed - 

 at the apex. On one of the heads they have fallen off, indicating 

 that they are not persistent like those of Tagetes. The disk 

 flowers form an erect cylindrical bundle, while the entire head is 

 subtended by an involucre not at all like that of the genus Ta- 

 getes, but composed of a few linear sepal-like bracts as stated 

 above. 



Faihng to find the plant in the genus Coreopsis, the writer^^ 

 carefully examined the plants belonging to allied genera. At* 

 last, in the genus Cosmos, he came upon a species corresponding 

 in all respects with Hernandez's figure. The long sought Xochi- 

 palli proved to be Cosmos sulphureus, a species which, though 

 figured the latter part of the eighteenth century by two eminent 

 botanists, had never been associated with the dye-plant described 

 and figured by the great protomedico a century previously. To 

 verify the discovery, a decoction of the flowers was made for the 

 writer by Dr. L. A. Hawkins, Plant Physiologist, of the Depart- 

 ment of Agriculture. Almost immediately the water became 

 suffused with an orange tinge, and on the addition of a very, 

 small quantity of alkali it changed to a rich orange-red, the color 

 of the xochipalli described by Hernandez. 



Though never hitherto connected with the classic "flower- 

 color" used by the Aztecs in pamting their codices. Cosmos sul- 

 phureus is not a rare plant. Specimens of it were lacking in the 

 United States National Herbarium until 1886, when it was en- 

 countered by the veteran explorer Dr. Edward Palmer in the 



