PREFACE, 
One influence of the extension of American jurisdiction over Porto 
Rico and the Philippine Islands, in the year 1S08, was to create a 
demand for information about the vegetation of those islands. All 
contained a tropical flora, and American botanists had devoted little 
attention to the study of tropical plants. The information demanded 
regarding the Porto Riean flora was largely of a popular and com- 
mercial character and was not at all to be satisfied by the existing 
and available technical works on the West Indian flora. In the course 
of their investigations on tropical agricultural plants in Porto Rico, 
Mr. O. F. Cook, botanist in charge of investigations in tropical agri- 
culture, Department of Agriculture, and his assistant, Mr. G. N. 
Collins, have collated a large amount of information on the economic 
plants of that island such as is not suitable for incorporation in their 
detailed reports on staple and special agricultural plants, which are 
published by the United States Department of Agriculture. This 
information has been brought together in the present paper on Eco- 
nomie Plants of Porto Rico, Fortunately the plant names in use 
among the people of Porto Rico are appiied with approximate pre- 
cision, so that by adding the botanical identification of a plant to its 
Porto Rican popular name we have in most instances a direct key to 
its botanical name and position. The use of illustrations reproduced 
from good photographs conveys in a simple and direct way informa- 
tion which no amount of technical description could replace. Avail- 
ing themselves of personal observation, the facts published by others, 
a study of collections, the use of photographs, and the intimate per- 
sonal knowledge the Porto Ricans have of their useful plants, the 
authors have produced a work which will be of great value to botan- 
ists and to all other persons seeking information about the common 
and useful plants of Porto Rico. 
FREDERICK V. COVILLE, 
Curator of botany. 
III 
