MIDDLESEX FLORA. 95 



S. sericea, Marsh. Silky AVillow. 

 Medford (G. E. Davenport) ; Arlington (Wm. Boott) ; Hopkinton 



(L. L. Darae). Not common. May. 

 S. petiolaris, Smith. Petioled Willow. 

 Medford (G. E. Davenport) ; Winchester (L. L. Dame) ; Cambridge 



(L. H. Bailejs Jr.), et al. Apr.-May. 

 S. PURPUREA, L. Purple Willow. 

 Arlington (Wm. Boott); Medford (L. L. Dame). Api'.-May. A 



native of the Old World, sparingly naturalized. 

 S. viminalis, L. Basket Osier. 



West Medford (C. E. Perkins). Adv. from Eu. May. 

 S. cordata, Muhl. Heart-leaved Willow. 



Widely distributed, but not common. Apr.-May. 

 S. cordata X sericea, Bebb. ("S. myricoides, Muhl. ! not the S. 



cordata, var. myricoides, of Gray, Man.") — M. S. Bebb. 



Near Fresh Pond, Cambridge (L. H. Bailey, Jr.) 

 S. rostrata, Puch. (S. livida, Wahl., var. occidentalis. Gray.) 



Livid Willow. 



Common. Apr.-May. Mr. Bebb ranks this willow as a sub-species 



of S. livida. 

 S. lucida, Muhl. Shining Willow. 



Rather common. May. 

 S. nigra, Marsh. Black Willow. 



Cambridge, Medford, Winchester, et al. Occasional. 

 S. nigra, Marsh, var. falcata, Gray. 



Cambridge (Dr. C. W. Swan) ; Concord. (Walter Deane). 

 S. FRAGiLis, L. Brittle Willow. 



Hybrids in which S. fragilis predominates are not uncommon; a 



Medford specimen Mr. Bebb pronounces "almost pure fragilis.''^ 



May. 

 S. ALBA, L., var. vitellina, Koch. 



Chelmsford, Medford, Natick, et al. Not uncommon. May. 



"The typical S. alba is extremely rare in the United States, and 



what Anderson, Wimmer, and the German botanists generally 



regard as genuine S. fragilis I have not seen at all ; but the var. 



vitellina is very common, as are also a host of hybrid forms between 



alba and fragilis, representing S. viridis, Fr., S. Russelliaua, Sm., 



'&c. These hybrids, perplexing enough in themselves, are rendered 



still more inextricable, with us, by a further cross — by no means 



rare — with native lucida," — M. S. Bebb. 

 S. myrtilloides, L. Myrtle Willow. 



Cambridge, Belmont, Wakefield, Chelmsford, et al. Rather common. 



May. 



