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northern Canada, and II, covering most of the rest of Canada, were 

 both largely included in zone I of the first edition. Zone VII, the 

 southernmost from which plants are considered, does not extend 

 quite as far south as zone VIII of the first edition, as a result a 

 few southern plants (including the only palm) given in the earlier 

 edition are omitted. Plants that will not grow north of South 

 Carolina or Louisiana in the east, or central California in the 

 west are not included, otherwise all woody plants native or intro- 

 duced to North America are given. It is interesting to note, as in 

 the first edition, the number of varieties recognized for common 

 native trees, as a random sampling — three varieties of the Quaking 

 Aspen (Populus tremuloides), six of the Black Cherry (Prunus 

 serotina), five of the Sugar Maple (Acer saccharum), four and 

 three hybrids of the American Basswood (Tilia americana) and 

 four of the Flowering Dogwood (Cornus florida). The term shrub 

 is made to include such small forms as Spotted Wintergreen, Pip- 

 sissewa, Trailing Arbutus, Periwinkle and Linnaea. Moss Pink 

 (Phlox subulata), given in the first edition, is omitted as is Gilia 

 pungens for which Gilia calif ornica is substituted. 



Most of the work, as would be expected, is little changed ; but 

 the Bamboos have been entirely rewritten with ten instead of three 

 genera — the result of recent study which has greatly divided Arun- 

 dinaria as well as some of the other genera. The genus Rosa has 

 been rewritten, with four instead of two subgenera and fewer sec- 

 tions, but the species little changed. Rhododendron has also been 

 rewritten, eighty-five instead of sixty-one species being described. 

 The treatment of species and genera is conservative — the Choke- 

 cherry is still Prunus; Cranberry, Vaccinium; and Box-Elder, 

 Acer. But it is hard to reconcile with this conservative attitude 

 the dividing of the genus Sequoia, the big tree becoming Sequoia- 

 dendron giganteum. 



As in the early edition there are complete keys to families, 

 genera and species. The list of publications with illustrations of 

 described species has been enlarged and the list of authors has 

 been increased to include all the names cited, about 1,150. A total 

 of 2,550 species are described. The index, which includes all the 

 varieties and synonyms, lists 14,300 names. This new edition at 

 once goes on the "must have" list of all workers with cultivated 

 woody plants. 



