400 BOTANICAL GAZETTE [NOVEMBER 
that the most vigorous of the beans had produced but two or three 
pods, some of the tepary plants had as many as 200 ripe pods and 
the average was more than 100. During 1911 pink beans which 
were planted May 17 had not bloomed on account of the heat as 
late as August 20, although they have been well irrigated during 
that time (fig. 1). Teparies planted alongside the beans on the 
same day and given identical treatment had by that time ripened 
an abundant crop of seed. It is a common statement among the 
Pima Indians that when the beans are destroyed by insects the 
teparies go free. 
It has now been noted that the traditional origin of the bean 
and the tepary are distinct, that physiologically the tepary differs 
from the bean in being more resistant to heat, drought, and insect 
attack, and hence is more productive in hot regions. It remains 
yet to describe those morphological distinctions which compel 
the conclusion that the tepary does not belong to the same species 
as does the kidney bean. 
Characters of the tepary 
The characters of tepary are best indicated by contrasting 
them with those of the kidney bean (Phaseolus vulgaris) and the 
lima bean (P. lunatus). The seeds are smaller, averaging about 
0.15 gm. instead of about 0.23 gm. for beans and 0.50 gm. or 
more for limas. When present at all, the markings or flecks on 
teparies are much finer than on the other two. The seed coat of 
the. tepary lacks the characteristic glossiness of the kidney bean. 
The length of the petioles of the first pair of aerial leaves are 
Strikingly different in the tepary and the varieties of P. vulgaris 
and P. lunatus. Measurements of the mature petioles of the first 
pair of aerial leaves on a large number of seedling of several varieties 
of each gave for the average of the tepary 4.3 mm., for beans 
24.33 mm., and for the limas 43.7mm. The first pair of aerial 
leaves of all three species are simple, but those of the tepary differ 
from the others in having truncate instead of cordate bases (figs- 
2 and 3). They are also smaller and narrower, the averages being 
as shown in table I. 

