BOTANICAL INFORMATION. 573 
feet, to my great surprise I discovered a variety of plants, 
and amongst them growing on some stunted bushes a beau- 
tiful new species of Tropeolum, somewhat similar to 7. bra- 
chyceras, but with a more expanded flower, twice the size, 
and the plant altogether much more robust. I obtained fine 
tubers and specimens of this plant, but, from what I learn, 
they have been — lost on their passage to Valpa- 
raiso. 
* Having pieced mules in Cobija for myself and two 
Chilian servants, we took the road to Potosi, and in three 
days reached the little town of Calama, forty leagues distant 
from Cobija, situated in the desert of Atacama. It was 
within thirteen leagues of this place, that I had the pleasure 
of finding in February the beautiful Pélocereus. In my 
last letter from Valparaiso, I gave you a few remarks on 
this interesting plant; since then I have seen more of 
its habits, &c., therefore shall again trouble you with 
the following observations. It is generally found on the 
slopes of bold, rugged mountains, whose aspect is towards 
the north, where it enjoys plenty of sun and a dry sandy soil. 
Frequently twenty or thirty stems proceed from the same 
root, the outer ones partly lying on the ground forming a 
curve upwards, the inner stems grow erect and are those 
which are most hairy, they seldom reach the height of 
4 feet, and from the older stems in the centre spring the 
flowers, which are of a beautiful dark red, about the size of 
C. flagelliformis ; the seed-vessels are round or rather oval, 
smooth and shining on the surface, hollow within and destitute 
of a pulpy substance ; the seeds are round and of a blackish 
colour. The place where I found it most abundantly, was 
near the vicinity of the city of Potosi at an elevation of 
12,000 feet; therefore you may judge from this it is fre- 
quently exposed to frost. In the language of the Quichuan 
Indians, it is called Quchuallo, pronounce Ke-wal-yo. The 
other enormous species of Cereus, which I mentioned, grows 
in the same localities and often attains the height of 20 feet. 
The flowers proceed from the top, and are of a dark red 
