128 THE AMERICAN BOTANIST 



but they are not such as to seriously interfere with the pur-: 

 pose of the book. Like most works of this nature it may be 

 depended upon to offer stimulating material upon which the 

 intelligent teacher can draw for illustrating any particular 

 subject. It is published by the American Book Company, New 

 York. 



Plants for Cold Climates. — With most plants, hardiness 

 is only a relative term. A few arctic plants may be called 

 truly hardy, but all the rest are only comparatively so. In 

 certain regions, or under certain favorable conditions they 

 may survive the winter without protection, but each species 

 has its own limits beyond w^hich it is not hardy, though one 

 may endure a season of cold that would kill another. 

 Dwellers in our northern tier of states find the matter of hardi- 

 ness in garden plants of much more importance than those 

 further south consider it. In Pennsylvania, Ohio and Illinois 

 most of the commonly cultivated perennials prove hardy, 

 farther north, one after another give up the battle. Such con- 

 ditions make all attempts to acclimatize our plants in more 

 northern regions very interesting. At Devils Lake, North 

 Dakota, is a nursery said to be the most northern in America 

 and one can glean from the catalogue of plants offered for 

 sale, some idea of the hostile climate there encountered. Of 

 course the locusts, magnolias, coffee tree, ailanthus and the 

 like are absent. The willows, black walnut, box elder, elm, 

 hop tree and poplars do well while the pea tree (Caragana 

 arborescens) and Russian olive (Eleagniis angiistifolia) are 

 added to the list. Among shrubs we note the June berry 

 Shepherdia argentea, lilac, ninebark, snowberry, and several 

 species of spiraea and honeysuckle. The day lilies perennial 

 poppy, iris, peony, bleeding heart, larkspur and colum- 

 bines are all hardy in that region. Experiments are in pro- 

 gress to test the hardiness of other plants as well as to intro- 

 duce the showy native flowers into cultivation. 



