COMPAEATIVE HARDINESS. 41 



R. dauricum, and its variety, atrovirens, will 

 stand in any exposure. R. caucasicum and chri/- 

 santhemmn should prove hardy, but they are seldom 

 found in cultivation. 



R. lapponicum is a native of high mountain ranges 

 and northern latitudes, but is an " Alpine " of diffi- 

 cult cultivation. In its native habitat it is probably 

 protected by snow during the winter. 



R. maximum is perfectly hardy ; and any hybrids 

 raised from it would probably partake of this char- 

 acteristic. 



-R. Catawbiense is hardy as far north as Boston, 

 though in severe winters the foliage has sometimes 

 been a little browned. 



The hybrids of Catawbiense vary greatly in hardi- 

 ness. Though thus popularly called, they are of 

 mixed blood, and are hardy just so far as they 

 resemble the hardy parent. As a general rule, the 

 bright colors and the deeply spotted varieties will be 

 found tender ; but we have great hopes that some of 

 the newer seedlings, which in color are superior to 

 any of the old kinds, may prove hardy with us. 



In the description of varieties in Part II., we pro- 

 pose to give our experience of the hardiness of the 

 several kinds. We must say, however, that the 

 experience of one locality is not necessarily that of 

 another, differing but little in climate. Each one 

 must experiment for himself with doubtful kinds, 

 and thus only can he ascertain the true rule for his 

 guidance. 



There are many Rhododendrons that in branch 

 and bud are hardy, but of which the foliage is dis- 



