152 
AMENTACEOUS TREES. 
benefit land by their direct influence, but, in 
general, are merely the occasion of improvement 
by manuring and cleaning. An ameliorating 
crop either destroys weeds by taking entire pos- 
session of the soil; or occasions weeds to be de- 
stroyed, oxygen to be absorbed, and inert matter 
to be decomposed, by frequent workings of the 
soil; or exhausts mischievous excrementitious 
deposits of preceding cereal crops; or makes such 
excrementitious deposits of its own as are useful 
to succeeding cereal crops; or occasions a tho- 
rough preparation of the soil, by means of pre- 
vious manuring and a series of ploughings, for 
subsequent cereal crops; or brings large contri- 
butions of manure, and a great amount of useful 
mechanical pressure, by its being fed off; or con- 
tributes the whole of its own substance to the 
soil by being ploughed in as a green manure; or 
makes large returns to the soil by contributions 
of its substance to the dung-heap of the farm- 
yard. See Rotation and Fatiow. 
AMENTACEOUS TREES. Trees whose blos- 
soms have the form of amenta or catkins. Hach 
series of characteristic blossoms hangs somewhat 
in the form of a cat’s tail; and consists of an 
ageregation of scaly or cottony flowers, without 
either calyx or corolla. If the cone-bearing trees 
be excepted, the amentaceous trees constitute 
the great body of the timber trees of Europe; 
they comprise the genera of the alder, the birch, 
the willow, the poplar, the liquidamber, the plane, 
the hornbeam, the hop-hornbeam, the chestnut, the 
beech, the hazel, and the oak; but, in consequence of 
very considerable differences in the form of their 
amenta, they have been subdivided by modern 
botanists into four tribes, represented by respt-- 
tively the birch, the willow, the plane, and the oak. 
AMERICAN ALOE,—botanically Agave. A 
genus of gorgeous, evergreen, tender shrubs of the 
| pine-apple tribe. The known species are ten in 
number; two ofthem, saratto and vivipara, are bien- 
nials; and all the others are perennials. Yet, if 
mere length of duration be considered, all are per- 
ennials; and if monocarpous habit be considered, 
allare biennials. See the article Brannran Puants. 
All are natives of America,—chiefly the countries 
around the Gulf of Mexico; and all closely re- 
semble one another, yet vary in height from three 
feet to about thirty. The common or great Amer- 
ican aloe, Agave Americana, was introduced to 
Britain in 1640; and has long been a great favour- 
ite in our greenhouses, and a popular succulent 
throughout Europe. Its form is similar to that 
of the yucea and the aloe, but more massive and 
elegant. Its stem, if it can be said to have one, 
is scarcely distinguishable from the crown of the 
root ; its leaves are toothed, spiny, spreading, and 
very fleshy, and sometimes measure ten feet in 
length, fifteen inches in breadth, and eight inches 
in thickness; its flower-stem is from twenty to 
thirty feet high, sends out curved branches on 
all sides like candelabra, and grows at the sur- 
prising rate of six inches or upwards every twen- 
AMERICAN ALOE. 
ty-four hours; and its flowers have a greenish | 
yellow colour, come out in thick clusters at every 
joint of slender shoot of the branches, have six 
long stamina crowned with yellow summits and 
placed round the style, and sometimes on a single 
plant number considerably upwards of two thou- 
sand. A plant, when in flower, is an object of 
surpassing beauty ; and if properly managed, will 
retain all its freshness, and produce a succession 
of flowers, during about three months. The 
American aloe was formerly believed by British 
gardeners to be capable of flowering only in its 
hundredth year, and is still popularly believed 
to be capable of flowering only in its fiftieth year ; 
but it really flowers in its native country in its 
ninth or tenth year,—it flowers in Great Britain 
in any year from its fifteenth or twentieth to its 
sixtieth or seventieth, or never flowers at all, 
simply according to the treatment it receives ;— 
and were it managed with due skill and care, it 
would probably be, in all instances, brought in a 
very few years into a flowering condition. But 
any one plant never flowers a second time, each 
plant thoroughly exhausting itself by fructifica- 
tion, and immediately perishing, in the same 
manner as an annual or a true biennial. Its 
flower-stem and young shoots, in the earlier 
stages of their growth, have the appearance of 
a gigantic asparagus; and in their full-grown 
condition, look, at a little distance, like a slender 
and pyramidally outlined tree. A curious ob- 
server, however, may from year to year see hun- 
dreds of American aloes, before enjoying the ex- 
quisite luxury of seeing either the flowers or the 
flowering-stem of even one plant. 
The American aloe grows like an indigenous: 
plant in Sicily, the south of Italy, and the south 
of Spain. It is in general use, throughout south- 
ern and central Italy, as an ornament to piers, 
parapets, and the exterior of houses; and imita- | 
tions of it in painted copper, are used for the 
same purpose throughout Lombardy. It issome-. | 
times grown for hedges in Spain, Portugal, Sicily, | 
Calabria, and the West Indies. The juice of its | 
leaves, after being inspissated and mixed with 
ley ashes, is used, in Jamaica, as a substitute for 
soap, and lathers with salt water as well as with 
fresh. Its leaves are used, in the West Indies, 
for scouring floors and kitchen utensils. The 
decayed interior substance of the decayed flower- 
stem is used for tinder. The fibres of the leaves, 
prepared similarly to those of flax, are manufac- 
tured into strong thread. The Indians use its 
‘prickles as substitutes for needles; they eat its 
flower-buds in both a boiled and a pickled con- 
dition; they employ some parts of it for medi- 
cine, and convert its roots with sugar into sweet- 
meats; they manufacture from it thread, ropes, 
cloth, and paper; and they use its flower-stems 
for props and rafters to their houses, its leaves 
for thatch or covering, and both flower-stems and 
leaves for fences. The Mexicans extensively cul- 
tivate it for the sake of its sap, and manufacture 
