sure to less than 13 hours of daylight resulted in an ap- 
preciable delay in flowering date of Phaseolus coccineus 
which was accompanied by tuberization of the root sys- 
tem. Longer day-lengths brought about earlier flowering, 
and tuberization did not occur. Chiapas, at about 16° 
North latitude with days of less than 13 hours of light 
during the growing season, corresponds to the delayed 
flowering-tuberized root situation, while Tamaulipas at 
about 23° North latitude has photoperiods of more than 
13 hours during most of the growing season. 
In the highlands of Chiapas, the fleshy roots of runner 
beans are eaten by Tzeltal Indians (fieldwork, 1957). If 
this be a retention of an early practice (as suggested by 
Edgar Anderson in conversation), then it is possible that 
domestication of runner beans was based upon root as 
well as seed use. Such a practice could not have occurred 
in ‘Tamaulipas since tuberization does not occur because 
of the long-day, short-night condition. 
The early presence of Phaseolus coccineus remains 
makes it advisable to examine any wild populations of 
bean species which are otherwise known only as cultivars. 
Kaplan has collected P. coccineus in a variety of situations, 
including pine and oak forests and deep barrancas, in 
Chiapas. None of these sites has been under cultivation 
in the memory of local inhabitants, but the strong ten- 
dency of this species toward perenniality leaves open the 
possibility that these plants are relics of cultivation. 
However, Ephraim Hernandez X. has stated (in conver- 
sation) that P. coccineus, and other closely related spe- 
cies, Which are not escaped or relic cultivars do occur in 
Chiapas. Probably the most important related species is 
Phaseolus polyanthus Greenman which also seems to be 
planted with P. coccineus and reaches the markets with 
beans of this latter species. Oliver W. Norvell has noted 
such market mixtures in seed collections in the herbarium 
[ 51 | 
