UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1422 
ington, D. C. T October, 1926 
THE HEVEA RUBBER TREE IN THE AMAZON VALLEY 
By Carl D. La Rue, 1 Specialist in Rubber Investigations, Office of Cotton, Rubber, 
and Other Tropical Plants, Bureau of Plant Industry 
CONTENTS 
Introduction 1 
Purpose of the expedition 3 
Personnel of the expedition 4 
Itinerary 4 
The genus Hevea 5 
Geographical distribution 7 
Rubber-bearing species 8 
Status of the rubber industry in the Amazon 
Valley 9 
Rubber reserves of the Amazon Valley 36 
Page 
Plantation possibilities in the Amazon Valley. 36 
Types of Hevea brasiliensis in the Amazon 
Valley 46 
The disease situation 56 
Other trees which bear rubber or similar sub- 
stances 57 
Need of introduction of other species of Hevea. 65 
Summary and conclusions 66 
Literature cited 67 
INTRODUCTION 
The use of rubber for one purpose or another has been known to 
man for an indefinite length of time; for centuries at least. In 1536 
Oviedo y Valdes (30) 2 in his Historia general y natural de las Indias, 
which was published in full at Madrid in 1851-1855, mentions different 
articles made from the latex of the rubber tree by the Amazonian 
Indians. 
La Condamine (13), who went to South America in 1734 to make 
astronomical observations, sent a small quantity of rubber to the 
Paris Academy in 1736. Later, in 1745, he described the uses to 
which rubber is put by the Omagua Indians of the Maranon River, 
whom he visited on his trip from Quito across the Andes and down the 
Amazon to its mouth. In this paper he states that this " resin," as 
he calls it, is called "calmchu" (pronounced, as he says, "cahout- 
chou") in the Province of Quito near the sea. It is also very com- 
mon on the Maranon, where it is used in the same way as in the other 
region. 
Later, in 1751, La Condamine (14) tells of his observations in 1736 
on rubber in the Province of Esmeraldas. Here he contradicts his 
former statement as to the name of the product in this region and says 
1 The thanks of the writer are due the members of his own party, of the party from the Department of 
Commerce, and of the Brazilian Rubber Commission. He is also indebted to the Governors of Para and 
of the Acre Territory in Brazil, and of the Northwest Territory of Bolivia; to the staff of the Museu Goeldi 
in Para, to the Commercial Association of Manaos, to Nicholas Suarez, of Suarez Hermanos, and to a num- 
ber of other officials and private citizens who aided the expedition in many ways. 
2 The serial numbers (italic) in parentheses refer to "Literature cited" at the end of this bulletin. 
96522°— 2G 1 1 
