1883.] Botany, 415 
It cuts through all the tissues so that when the top dries up and 
begins to sway in the wind, it is broken off very readily and 
evenly. One might perhaps think that the wrenching of the 
stem was the only cause of the separation, but I satisfied my- 
self that a real joint is formed, by examining plants still green. 
The bushy top of the Psoralea is higher relatively from the ground 
than that of the Amarantus, so that it is roughly spherical without 
the root—/. E. Todd, Beloit, Wis. 
WHENCE CAME THE WILD POTATOES OF ARIZONA.— Several years 
ago August Fendler collected near El Paso, New Mexico, a kind 
of potato used largely by the Navajo Indians, and which resem- 
bled the cultivated potato, except in size ; the tubers,are not larger 
than filberts. Dr, Gray named the species for the discoverer— 
Solanum Fendleri. The tubers have been heard of but once since, 
and that was in 1879, when Dr. Palmer collected a handful that, 
being sent to the Agricultural Department at Washington, found 
their way at last into the hands of Prof. Meehan, who planted 
them, and cultivated them for a few years, when, for no apparent 
reason, they were lost. 
uring the summer just past (1882), we discovered a new 
locality for this species in the Huachuca, New Mexico; also of 
another species, formerly known from the mountains of Colorado— 
S. Famesti Torr. The latter, we believe, has never been tested in 
cultivation, yet it is very promising, for its short stolons and readily 
improved size of tuber. Both species we found invading the few 
gardens of the region, seemingly rejoicing in being able to escape 
the attacks of the gardener by reason of their close resemblance 
to the genuine S$. tuberosum. Though found also on the high 
slopes in the shade, yet they were larger in the gardens. Hum- 
) Idt shows us that the potato was not known in Mexico at the 
time of the Incas, while it is now found in various parts of the 
republic, in a wild, neglected condition. 
Now whence came it? Did an immigration subsequent to that 
of the Aztecs bring this esculent and plant it along the Rio 
cludes (in his latest works) that the so-called distinct species of 
Solanum Fendleri is only a form of the original S. tuberosum, and 
Peg Famesii—that although “ it appears on the whole to be 
rung and why is their source lost? Humboldt argued, in 1812, 
itginia, it must have been derived from a plant indigenous to the 
a half hemisphere, and thus he pointed out this discovery nearly 
™ century afterward. But Dr, Gray argues that the potato 
Vou, XVIL—NO, iv. 29 
