288 A TEXT-BOOK OF BOTANY 
culture has developed rapidly in importance, and is suited 
to almost all soils. 
(2) Svtone-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 (§ 148) (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, these 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 (ncctarine) in external appear- 
ance, and having the smooth stone of a plum. They also 
