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 

 growth 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 division. 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 man}' 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 Eucalyptus rostrata, 

 E. nidi*. E. leucoxylon, E. hemiphloia, E. polyanthema, E. mellio- 

 dora, E. corynocalyx, K. tereticornis, and L. s<iJuhris. 



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 

 Eucalypts are grown most extensively and most successfully. 



