Panicum sonorum Beal: Sauwi, panic grass. 
This is a little-known grass cultivated by the Warihio 
of Sonora and Chihuahua as a cereal (81). It is said to 
have been cultivated also by the Cocopa (41, 96). It is 
probably an indigenous cultigen of this area, though the 
species also occurs in southern Mexico. It is of particular 
interest since very few true cereals, other than maize, 
were cultivated in the New World. Two South Ameri- 
can grasses of similar status are now believed to be ex- 
tinct (177). (41, 81*, 96). 
Parmentiera edulis DC.: Quauvilotl, cuajilote. 
This tree, related to the calabash, is cultivated in many 
parts of Mexico for its sweet fruits which are eaten either 
raw or variously cooked. The tree now ranges from 'T'am- 
aulipas and Sinaloa to Central America and is probably 
native at least to southern Mexico. (17, 133, 191*, 200) 
Persea americana Mill.: Ahudcatl, pahua, agua- 
cate, avocado; P. Schiedeana Nees: Chinini, coy6. 
The nutritious avocado, now becoming more popular 
in the North, has long been an important food in Middle 
America. There are three groups recognized within P. 
americana: the Mexican race, a thin-skinned, small- 
fruited type centering in the Mexican highlands and 
sometimes designated as P. americana var. drymifolia 
(Schlecht. & Cham.) Blake; the Guatemalan race, prin- 
cipally Central American; and the ‘‘West Indian”’ race 
which occurs in the lowlands of Central America and 
northern South America. Williams (219) states that the 
complex of wild forms, to which P. americana is most 
closely related, ranges from Mexico to Honduras and 
probably to Costa Rica. Popenoe (152) has found what he 
believes to be wild trees of the Mexican race on the slopes 
of Orizaba and supposed wild trees of the Guatemalan 
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