94 



ROSACEAE. 



SPIRAEA. 

 (Family Rosaceae). 



Shrubs, usually low and little 

 branched or else with wandlike 

 branches: deciduous. Twigs ter- 

 ete or angled from the nodes, often 

 very slender, more or less zig-zag: 

 pith small, roundish, continuous. 

 Buds small, solitary or in a few 

 cases collaterally multiplied, ses- 

 sile, globose to subfusiform, mostly 

 with some half-dozen exposed 

 scales. Leaf-scars alternate, half- 

 round or crescent-shaped, minute, 

 often much raised: bundle-trace 1: 

 stipule-scars not evident. 



Spiraea, like Pyrus and Prunus, 

 is a genus which has been very 

 differently defined by different 

 botanists, for some of whom it in- 

 cludes the plants here considered 

 under the genera Neillia, Physo- 

 carpus, Sorbaria and Stephanan- 

 dra. The most concise winter-key to any considerable num- 

 ber of its species is that of Bosemann, which treats it in this 

 broader and older sense. The comparatively few species that 

 enter into ordinary American planting} and are considered 

 here differ for the most part in several distinctive ways, and 

 their buds belong to several unmistakable types. 



Winter-character references: 8. ariaefolia. Bosemann, 

 76. 8.. ft etulae folia. Shirasawa, 244, pi. 4. 8. cana. Schnei- 

 der, f. 175. X & cantoniensis. Shirasawa, 246, pi. 4. 8. 

 chamaedry folia. Bosemann, 75. 8. crenata. Schneider, f. 

 174. 8. discolor. Schneider, f. 179. 8. hypericifolia. Bose- 

 mann, 77; Schneider, f. 175. 8. japonica. Shirasawa, 274, pi. 



