DICOTYLEDONS: ARCHICHLAMYDE^E 291 



ruled 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- 

 ininnsii ) of the Archichlamydcac, and is chiefly distinguished 

 by its very irregular (lowers 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 

 Archichlamydese that f he orchids do among Monocotyledons. 



