104 SILVA OF NORTH AMERICA. LEGUMINOSE. 
ripe pods! of the Mesquite supply the Mexicans and Indians with a favorite and nutritious food, and are 
greedily devoured by most herbivorous animals.” A gum resembling gum arabic? exudes from its stems. 
From the shores of the Gulf of Mexico to those of the Pacific Ocean the Mesquite is the most 
important tree of the districts immediately north and south of the boundary of the United States; it is 
the most valuable leguminous tree of the North American forests, and the amount and quality of the 
food and fuel which it produces in vast territories where both are scarce make it one of the most 
valuable of all trees. In spring and summer its bright green foliage and abundant fragrant flowers 
give life and beauty to dreary desert slopes and arid plains, and delight the eye of the traveler, who, 
however, in the broken and illusory shadows cast by its thin and scattered leaves, vainly seeks protection 
from the burning rays of the sun.’ 
The earliest botanical account of Prosopis juliflora was published in 1788 by the Swedish traveler 
Swartz, who had found it naturalized in Jamaica. It was first found within the territory of the United 
States, in the valley of the Canadian River near the northern limits of its distribution, in 1820, by Dr. 
Edwin P. James,® the naturalist of Long’s Rocky Mountain Expedition. It was introduced into 
England from Chile in 1832,° and is now cultivated in most of the warm dry parts of the world as 
an ornamental or fodder plant,’ or in hedges, for which its hardiness and stout well-armed branches 
make it valuable. 
Prosopis juliflora is easily raised from seeds,*® which readily germinate and produce plants that 
grow rapidly in good soil, and at the end of four or five years form shrubs with stems several feet in 
height. 
1 The nutritious portion of a Mesquite pod is about fifty-three 
per cent. and consists of vegetable albumen, gum, and grape-sugar, 
with traces of fat and salts. The remainder, or nearly one half, 
made up of the outer and inner walls of the pod and of the seeds, 
is indigestible and always voided. As only about one half of their 
weight is assimilable, Mesquite pods furnish much less valuable fod- 
der than oats or corn ; it is rich in sugar and nitrogen but deficient 
in starch and salts. The unripe pods are bitter and of no value as 
food ; when fully ripe they fall to the ground and should then be 
collected at once and stored in a dry place when they will keep 
until the crop of the following year ripens; if left upon the 
ground they soon deteriorate and decay. 
Mesquite pods are largely consumed by Mexicans and Indians, 
who grind them into coarse flour which they bake, after picking 
out the seeds, into cakes or tomales. Mesquite atole is made by 
boiling the pods and pounding them in fresh water into a pulp ; 
the liquid, which contains in suspension and solution all] the nutri- 
tious portion of the fruit, is then strained and makes a pleasant 
and healthful beverage. An infusion of Mesquite flour can be fer- 
mented and brewed into a weak beer, once largely used by the 
Apache and Comanche Indians. (See Havard, Am. Nat. xviii. 459.) 
* Gray, Mem. Am. Acad. n. ser. v. 304 (Pl. Thurber.). 
8 The gum which exudes from the bark of the Mesquite from 
May to September concretes in tears of various sizes and of a 
It is usually found on old trees with thick 
furrowed bark, accumulated in knot-holes and on the edges of 
bright amber color. 
wounds, and less commonly on smooth young stems. Sometimes 
the exudation does not concrete but spreads out on the bark in 
large flat resinous patches. Mesquite gum has the taste of gum 
arabic, from which it differs in not being affected by subacetate 
of lead ; it dissolves readily in three parts of water, and makes 
excellent mucilage. The quantity of gum naturally produced in 
a season by a large tree perhaps does not exceed half a pound, 
although the flow can be increased by making incisions in the bark, 
and it is not probable that Mesquite gum will ever become an 
important article of commerce. (Rosenthal, Syn. Pl. Diaphor. 
1052. — Rep. Dept. Agric. U. S. 1872, 452. — Havard, I. c.) 
* Prosopis julifiora is called Algaroba and its pods Algarobo by 
the Spanish-speaking inhabitants of Central and South America. 
5 See ii. 96. 
6 Loudon, Arh. Brit. ii. 661. — Nicholson, Dict. Gard. 
7 F. Mueller, Select Plants readily eligible for Industrial Culture 
or Naturalization in Victoria, 185.— Naudin, Manuel de I’ Acclima- 
teur, 439. 
8 A large proportion of the seeds do not grow without aid, 
through their failure to find suitable conditions for germination. 
Many decay where they fall, or are destroyed by insects, and the 
spontaneous growth of seedlings occurs only in favorable seasons at 
irregular intervals of years. The principal agencies for disseminat- 
ing the seeds are water which rushes down gulches and arroyos 
after heavy rains, and carries the pods to the banks and bottom- 
lands of rivers, where they find conditions favorable for germina- 
tion, as the Mesquite forests common in such situations attest, and 
herbivorous animals which void the seeds without having destroyed 
their vitality. The seedlings usually spring up in clusters, owing 
to the germination of several of the seeds from a single pod; on 
rich land the strongest of these takes the lead, gradually destroying 
the others, and forms a tree; on higher and drier land several of 
the seedlings develop equally and form a cluster of stems more or 
less united at the base. 
The Mesquite grows rapidly in good soil during the first four or 
five years of its life. Later its increase is slow ; in thirty years it 
may form a stem seven or eight inches in diameter which during 
the next fifty years may, under favorable conditions, increase three 
or four inches. Trunks more than a foot in diameter are probably 
over a hundred years old. (Havard, J. c. 456.) 
