AGRICULTURAL SURVEY OF SOUTH AMERICA 19 
TREES 
The native trees of Argentina are generally very different from those 
of the United States. The eastern populated third of Argentina 
was originally a treeless prairie — the great Pampa. About the only 
native trees found in this region are the ombu and the ceibu. The 
ombu {Pircunia dioica) is a stately tree that grows most frequently 
in the eastern part of the Province of Buenos Aires. A few isolated 
specimens are to be seen a few hundred miles west of the coast, and 
from Bahia Blanca north and eastward to Uruguay. They always 
grow as isolated specimens and on the open prairie are prominent 
landmarks. The wood is soft and unfit for either lumber or fuel. 
The second characteristic tree of the Pampa region is the ceibu 
(Erythrina cristagalli), which is a low-growing many-branched and 
very crooked tree that prefers the swamps and river banks. It is 
especially common in the delta region of the Parana. It rarely 
grows more than 20 feet high, the trunk and limbs are very crooked, 
the leaves are oval and glossy, the blossoms are a deep rich velvety 
scarlet, and the wood is of no apparent value and almost as light in 
weight as cork. 
The Pampa region is no longer treeless as the cities and towns 
and the owners of estates have planted millions of trees for ornament, 
shade, fuel, posts, and other uses during the last 50 years, more 
especially during the last 20 years. The varieties most commonly 
planted, in the order named, are Lombardy poplars, willows, eucalyp- 
tus, cottonwoods, china berries, casuarinas, which closely resembles 
a tall pine, cedars of various kinds, and black locusts. 
West of the Pampa region are great areas in which the calden, 
algarroba, and chanar predominate, followed by the semidesert regions 
in which low-growing thorny shrubs and cactus are the only living 
plants. 
The calden (Prosopis algorrobilla) is the most common and the 
most valuable tree found in the western part of the Pampa. It is 
a tree of extremely slow growth and lives to a great age in the semiarid 
region. It attains a height of about 35 feet and a trunk diameter of 
3 feet, with coarse, lichen-covered bark. The trunks are fairly 
straight, usually inclined in the direction of the prevailing winds, 
and the wood is very hard, a dark reddish brown in color, very brittle, 
and useful only for fuel. The calden forests have been exploited for 
fuel and millions of tons have been used for this purpose by the railway 
locomotives. Many train loads are exported to Buenos Aires and 
to intermediate cities and towns for fuel. 
The algarrobo (Prosopis campestris) is a leguminous tree with 
feathery compound leaves, and at a distance it resembles an apple 
tree. It is to be found growing within and on the outskirts of the 
calden forests. The wood is very hard and durable, mottled dark 
brown and white in color, takes a fine polish, and is used for lumber, 
posts, tool handles, and fuel. 
The chanar (Gourliaea decorticans) is more of a shrub than a tree. 
It grows throughout the same general region as the calden and 
algarrobo, but extends much farther into the semidesert region. 
It is about as ornamental as holly, is slow in growth, small in size, 
crooked in shape, and produces but little wood, although it is utilized, 
as fuel. 
