SALIX NIGRA, MARSH. 43 



entire, rounded to oblong, villous, ciliate ; stamens about 5 : 

 fertile catkins spreading ; calyx none ; corolla none ; bracts 

 ovate to narrowly oblong, acute, villous ; ovary short-stalked, 

 with two small glands at its base, ovate-conical, sometimes 

 obovate, smooth ; stigmas 2, short. 



Fruit. Fertile catkins drooping : capsules ovate-conical, 

 short-stemmed, minutely granular ; style very short : seeds 

 numerous. 



Horticultural Value. Hardy in New England ; grows 

 rapidly in all soils, particularly useful in very wet situa- 

 tions ; seriously affected by insects ; occasionally offered in 

 nurseries ; transplanted readily ; propagated from cuttings. 



PLATE XXI. SALIX NIGRA. 



1. Winter buds. 



2. Branch with sterile catkins. 



3. Sterile flower, side view. 



4. Sterile flower, front view. 



5. Branch with fertile catkins. 



6. Fertile flower, side view. 



7. Fertile flower, front view. 



8. Fruiting branch. 



9. Fruit enlarged. 



Salix fragilis and Salix alba. 



The fragilis and alba group of genus Salix gives rise to 

 puzzling questions of determination and nomenclature. Pure 

 fragilis and pure alba are perfectly distinct plants, fragilis 

 occasional, locally rather common, and alba rather rare within 

 the limits of the United States. Each species has varieties ; 

 the two species hybridize with each other and with native 

 species, and the hybrids themselves have varietal forms. 

 This group affords a tempting field for the manufacture of 

 species and varieties, about most of which so little is known 

 that any attempt to assign a definite range would be neces- 

 sarily imperfect and misleading. The range as given below 

 in either species simply points out the limits within which 

 any one of the various forms of that species appears to oe 

 spontaneous. 



