THE BOOK OF ROSES. 59 



OF THE THORNS. Considerable importance 

 has been attached to thorns as a specific cha- 

 racter, though without sufficient motive ; for 

 the beautiful thornless rose produced by Mon- 

 sieur Noisette, is in fact a variety of the Ever- 

 blowing rose, of which the branches are covered 

 with craoked thorns, and many thorny American 

 roses lose their arms when cultivated in France. 

 With regard to their position, thorns grow in 

 pairs under the stipules of the Rosa parvifolia, 

 and singly under those of one of its varieties, 

 called the single Small -leaved rose. They 

 abound of a crooked shape on the Carolina rose, 

 and become straight in its variety, the Cluster 

 rose ; and are not to be found at all on another 

 variety, the Hudsoniana. Thorns possess but 

 in one instance an unfailing specific character, 

 in the simplicifolia y where they are double, 

 or branching. 



OF THE LEAVES. There is so much diver- 

 sity in the foliage of rose-trees, that the leaf 

 does not lend itself to methodical classification. 

 The form, colour, and clothing of the leaflets 

 vary in almost every variety ; and we have even 

 obtained several varieties of which the leaves 

 are larger than those of the Rosa macrophylla, 

 and smaller than the parvifolia. 



As regards the number of leaflets, every leaf 

 must be either simple or composite. Bosc 

 attempted to establish a species called the 



