bian use extended only south to Costa Rica (30). In 
Mexico its cultivation has long centered in southern 
Veracruz, and it was probably little cultivated in other 
areas. (30*, 59*, 60a*, 133) 
Yucca elephantipes Regel: Iczotli, izote, yucca. 
This large tree is much planted for hedges, especially 
in Central America, where it is apparently introduced. 
The flowers are valued as a vegetable. Standley (192) 
considers it to be a native of Veracruz. Y. aloifolia L. is 
also cultivated at times. (115, 133, 191*, 192, 198, 194*) 
Zea Mays L.: Tlaolli, centli, maiz, maize, Indian 
corn. 
Maize has long been the most important crop plant for 
most of the Americas and certainly retains that title in 
Mexico. The interest in this plant has been such that an 
overwhelmingly voluminous literature has developed 
concerning the genetics, cytology, morphology, relation- 
ships, importance and origin of this cereal. There remain, 
nonetheless, many unanswered questions about maize 
and it will doubtless provide a fertile field for investiga- 
tors for many years to come. 
The nearest ally of maize is teosinte, Muchlaena (Zea) 
mexicana, Which occurs apparently as a wild plant in 
Guatemala and Chiapas and as a weed of cultivated areas 
in many parts of Mexico. Teosinte has at times been 
thought to be the wild ancestor of maize, but this idea 
now has very few adherents. Mangelsdorf and Reeves 
(129) have suggested that teosinte is actually of hybrid 
origin, maize and a species of T'ripsacum, a more dis- 
tantly related grass, being the parent species. Stebbins 
(195, p. 277) suggests that a cross might have been more 
readily effected between primitive maize and some ex- 
tinct species of T'ripsacum, with a lower chromosome 
[ 150 | 
