PREFACE. 
From 1887 to 1903 Mr. Henri Pittier resided in Central America, 
devoting a large part of his time to the study of its flora. He made 
extensive collections and published various botanical papers. Since 
coming to Washington, in 1903, Mr. Pittier has continued his study 
of this flora, and in the two short papers herein offered he presents 
some of the results. 
The third paper is a report by Mr. J. R. Johnston, of the Depart- 
ment of Agriculture, upon a collection of plants obtained by Capt. 
Wirt Robinson and Dr. M. W. Lyon, jr., in Venezuela. Mr. John- 
ston was asked to determine these species because he had himself 
collected in that-country and was somewhat familiar with its flora. 
The collection, though a small one, proves to contain five new species, 
and this paper, like many others in the Contributions, emphasizes 
the richness of the tropical American flora. 
Freperick VY. Covinye, 
Curator of the United States National Herbarium. 
IIL 
