PLATE XXIII 
Involucres of Egyptian cotton (natural size). 
Fig. i.—Pima variety. 
Fig. 2.—Gila variety. 
In these two varieties the bracts are shorter than in the Nubari and the Yuma 
varieties, and are separate, or nearly so, to the base. The Gila variety closely resem¬ 
bles the Mit Afifi variety in the character of the involucres. 
