288 A TEXT-BOOK OF BOTANY 



culture has developed rapidly in importance, and is suited 

 to almost all soils. 



(2) STONE-FRUITS. These valuable fruits are usually re- 

 garded as belonging to a single genus (Prunus). The pecul- 

 iar ripening of the ovary into fleshy and stony layers has 

 been explained ( 143) (Fig. 232). 



Peaches originated in China, where they have been cul- 

 tivated from remote times, and came to Europe by way of 

 Persia (hence the name Prunus Persica), and from Europe 

 to America. The beautiful flowers usually appear very early 

 in spring, and hence they are always in danger of late frosts. 

 On this account peach culture is attended with great risk, 

 and only those regions are favorable in which blooming is 

 likely to be held back and late frosts are rare. Curiously 

 enough, the'se risks are greater in the South than in the 

 North. It follows that the great commercial supply comes 

 from only a few regions. One of these is the Great Lakes 

 region, the prominent areas being in New York and Canada 

 along the southeastern part of Lake Ontario, along the 

 southern shore of Lake Erie, and on the eastern shore of 

 Lake Michigan (the Michigan " fruit belt ") ; a second great 

 region extends from the shores of Long Island Sound to the 

 Chesapeake Bay region; a third is northern Georgia and 

 Alabama; a fourth extends from southern Illinois across 

 Missouri into Kansas; and a fifth is almost the whole of 

 California that is not mountainous. Perhaps the best- 

 known peach-growing States are Maryland, Delaware, 

 Georgia, Michigan, and California. In a popular way 

 peaches are grouped as clingstones and freestones; but 

 there are intermediate forms, and the same variety may 

 be clingstone one season and freestone the next. Certain 

 smooth-skinned varieties are called nectarines. 



Apricots are intermediate between peaches and plums, 

 resembling a smooth peach (nectarine) in external appear- 

 ance, and having the smooth stone of a plum. They also 



