30 EUCALYPTS CULTIVATED IN THE UNITED STATES. 
region comprises all of the United States except a strip varying from 
100 to 300 miles in breadth along the southern and the southwestern 
border. 
In the second division the winters in most years are so mild that 
erowth is not checked; but during some winters a cold wave passes over 
the region that kills the whole, or a large part of the tree that has grown 
during the years in which no unusually cold period occurred. In this 
section Eucalypts never, or rarely, become dormant; and when a cold 
wave comes they are unprepared for it, the result being disastrous. 
This region consists of Florida and the adjacent coast region of the 
south Atlantic and the Gulf of Mexico. In Florida the conditions 
seem to be especially trying. Col. G. H. Norton, of Eustis, Fla., | 
writes, under date of February 6, 1900: 
All Eucalypts do well, but are killed to the ground when a very severe blizzard 
comes and the mercury falls much below 20° F. The trouble with the climate is, 
we have warm weather nearly all the time in winter, with an occasional cold wave. 
Possibly there may be a species as yet untried there that would 
withstand the conditions described. 
In the third division the minimum temperatures, while commonly 
quite low during midwinter, decrease so gradually during the latter 
part of autumn that the growth of the previous year has time to 
mature. It is thus able to endure a low temperature that would be 
fatal in the second division, discussed above, where the weather is 
alternately warm and cold. In other words, these evergreens, in 
common with the others of the region, both native and exotic, become 
dormant, just as native evergreens do in the colder first diyision. For 
this reason many Eucalypts can be grown there that can not be suc- 
cessfully grown in the second division, even though the mean tempera- 
tures of the winter may be higher in the latter. This region consists 
of the interior valleys of part of Texas, of southern New Mexico, of 
southern Arizona, and of southern California. In much of this region 
the summers are so dry and hot that many Eucalypts can not endure 
them. Consequently, the species that thrive in this section are those 
that both endure a very dry, hot atmosphere and become sufficiently 
dormant during the winter to endure the low temperatures that occur. 
The species of which this is known to be true are Lucalyptus rostrata, 
ky. rudis, £. leucorylon, EF. hemiphloia, EF. polyanthema, FE. mellio- 
dora, E. corynocalyx, E. tereticornis, and L. salubris. 
In the fourth division the climate is so equable that nearly all 
species of the genus Eucalyptus will grow in it. In this region the 
mercury rarely falls below 25° F. during winter nor rises much 
above 105° F. during summer, and the atmosphere is commonly 
moderately humid. This division consists of the coast region of central 
and southern California. It is the section of the United States in which 
Kucalypts are grown most extensively and most successfully. 
