AN ECOLOGICALLY ABERRANT BEGONIA.* 
BY WILLIAM TRELBASE. 
While making observations on an undescribed Agave 
which grows on the vertical cliffs of a deep marble canon 
a few miles above Iguala in the Mexican State of Guerrero, 
last summer, my attention was attracted by an abundant 
Begonia which grew in similar situations and differed from 
all of the other species of this genus that I had seen in pos- 
sessing only a single radical leaf, through the sinus of which 
a few-flowered scape arose, — naked except for a rather 
small leaf-like bract subtending its single branch, and - 
much smaller bracts in the inflorescence proper. Though 
my time was largely occupied with the Agave for which 
I had visited the cafon, herbarium and living specimens 
and photographs of the Begonia were secured, and a sub- 
sequent study of this material showed that the species 
belongs to the Section Huszia of modern writers, which 
Klotzsch regarded as a genus separable from Begonia, its 
only close ally being B. monophylla Pavon in DC. Prod. 
151;:284. The latter, so far as Ican learn, is known only 
from the type sheet in the Boissier herbarium, the label of 
which attributes it to New Spain. This group, Huszia, is 
that of the so-called tuberous begonias, some of which 
are now popular in cultivation, —nearly all of them 
coming from the Bolivian or Peruvian Andes. B. mono- 
phylla is said to produce a tuber 9 lines thick and to have 
a single petioled 12- to 15-nerved very shortly pilose leaf 
which is cordate or sometimes peltate, and rather large 
flowers. 
On showing my material to Dr. J. N. Rose, whom I met 
in the City of Mexico, I learned that apparently the same 
* Presented in abstract at the St. Louis meeting of the American 
Association for the Advancement of Science. — Science. n. s. 193170. 
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