510 STANDLEY: SPECIES OF AMARANTHUS 
species may be a native of that region rather than of Mexico. 
Until the plant is re-collected in the latter country, its occurrence 
there must remain very doubtful. 
The name acutilobus adopted by Uline and Bray in renaming 
this species is an inappropriate one, for the lobes of the leaves 
are not acute but rounded or obtuse. 
AMARANTHUS RETROFLEXUS L. 
In practically every manual of North American botany the 
statement is made that this species has been introduced into the 
United States from tropical America. The writer has seen a 
large series of specimens of the plant from North America and 
from the Old World, but he has seen none from Mexico or Central 
America. Probably it does reach northern Chihuahua and Sonora, 
since it is found in New Mexico and Arizona not far from the Mex- 
ican border. The species is not known to occur in South America. 
Linnaeus based his description upon plants said to come from 
Pennsylvania. It is probable that the species is a native of the 
southeastern part of the United States. It is apparently most 
abundant in the east, although it is found throughout the United 
States and in southern Canada. In the west it grows usually in 
localities where it might easily have been naturalized, but the 
same may be said of its occurrence in the east. Amaranthus 
retroflexus is now thoroughly established in many parts of Europe, 
Asia, and Africa. 
WASHINGTON, D. C. 
