DICOTYLEDONS: ARCHICIILAMYDEA 291 
rated fruit. Apples are usually propagated by budding and 
grafting (§ 24) the desired variety on hardy young trees. 
Pears are chiefly derived from a single European species 
and were introduced into this country by the earliest set- 
tlers (Fig. 282). Their most successful cultivation is in 
the Northeastern States (from New England to the Great 
Lakes) and on the Pacific Coast. In the central States 
extensive pear culture is attended with great risk on account 
of a dangerous disease known as pear-blight or fire-blight, 
the leaves turning brown or black as if scorched. This 
is one of the bacterial diseases (§ 77). Unlike most fruits, 
pears are very much improved when picked green and 
ripened indoors. 
Quinces are well known, but have not been developed in 
variety or in commercial importance as have apples and 
pears, this probably being due chiefly to the fact that they 
cannot be eaten raw. The most important quince orchards 
in the United States are in western New York. 
166. Legumes.—This is by far the greatest family (Legu- 
minose) of the Archichlamydez, and is chiefly distinguished 
by its very irregular flowers and its pods, which are derived 
from a single carpel and become more or less elongated and 
sometimes remarkably conspicuous (Fig. 283). It is the 
peculiar pods (legumes) that have given name to the fam- 
ily. The ordinary flowers, represented by the sweet pea, 
were thought to resemble a butterfly, and hence were said 
to be papilionaceous. The upper petal (standard) is the 
largest, and erect or spreading; the two lateral petals (wings) 
are oblique and descending; while the two lower petals are 
coherent by their lower edges and form a projecting boat- 
shaped body (keel), which encloses the stamens and pistil. 
The relation of this structure to pollination by insects has 
been described (§ 147). This family, in its irregular flowers 
adapted to insect-pollination, holds the same position among 
Archichlamydez that the orchids do among Monocotyledons. 
