perennial forms in the tropics. The slight, but fairly 
constant, morphological differences listed by Smith and 
Heiser include characters that sometimes serve to dis- 
tinguish the seeds of the two species, a fact which should 
be of interest to archaeologists. Centers of diversity for 
the peppers occur both in Mexico and in Brazil (206). 
The small-fruited peppers are weedy and now occur spon- 
taneously throughout the tropics. C. frutescens is found 
under seemingly natural conditions in the canyons of 
northwestern Mexico (81) and even as far north as the 
Baboquivari Mountains in Arizona(41). Too little is now 
known to determine with any certainty the origin of 
either species. They may have spread as useful weeds at 
avery early date and then been cultivated independently 
in two or more areas. (25*, 31, 41, 81, 92, 92a*, 93, 106, 
187*, 196, 206) 
C. pubescens R. & P., distinguished by purple flowers 
and purplish-black seeds, is known from both Central 
and South America (92). 
Carica Papaya L.: Papaya. 
The papaya, an herb of tree dimensions with melon- 
like fruit, is believed to have been known to the Mayan 
and perhaps to the Aztec cultures (118, 149). Several 
wild and cultivated species of this genus are found in 
South America, but Solms-Laubach (188) considered 
C. Papaya to be most closely allied to wild forms occur- 
ring in Mexico and the West Indies. Hybridization may 
have played a part in the origin of the cultivated form. 
Sauer (177) gives reasons for believing it to be Central 
American. (113, 138, 149, 177*, 188*, 191*, 192) 
The smaller-fruited C. cauliflora Jacq., which ranges 
south to Colombia and Venezuela, is listed by Standley 
as cultivated and perhaps native in Veracruz and Chia- 
pas (191). 
