36 MIDDLESEX FLORA. 



Sedum, Tourn. 



S. ACRE, L. Mossy Stonecrop. 



Melrose and Somerville (C. E. Perkins) ; Reading (Dr. C. W. 



Swan). Int. from Eu., and sparingly naturalized. June-July. 

 S. Telephium, L. Live-for-ever. Aaron's Rod. 



Roadsides, rather common. July-Aug. ISTat. from Eu. 



Sempervivum, L. 



s. tectorum, l. houseleek. 



Concord (Minot Pratt) ; Medford and Woburn, persistent and 

 spreading (L. L. Dame). Nat. from Evi. For description, see 

 Wood's Bot. & Fl. 



HAMAMELACE^. WITCH-HAZEL FAMILY. 



Ham AM ELI s, L. 



H. Virginica, L. Witch-hazel. 

 Common. Oct. -Dec. 



HALORAGE/E. WATER-MILFOIL FAMILY. 



Myriophyllum, Vaill. 



M. spicatum, L. 



Cambridge (Rev. Thos. Morong) ; Mystic Pond (Wm. Boott). 

 Specimen in the Boott Herb. July-Aug. 



M. verticillatum, L. 

 Fresh Pond, Cambridge (C E. Perkins). Julj^-Aug. 



M. ambiguum, Nutt., (var. natans, of Man.) 

 Tewksbury (B. D. Greene) ; Spot Pond (Wm. Boott). Specimen in 

 Boott Herb. July-Aug. 



M. ambiguum, Nutt., var. capillaceum, Torr. & Gray. 

 Townsend and Bedford (Dr. C. W. Swan) ; Spot Pond (Rev. Thos. 

 Morong) ; Concord, abundant (Walter Deane) ; Mystic Pond (Wm. 

 Boott). Growing entirely beneath the surface. 



M. ambiguum, Nutt., var. limosum, Torr. 

 Small ponds in Middlesex Fells (Wm. Boott). Growing in the 

 mud entirely out of water. Possibly this variety, with the one 

 immediately preceding, may be merely forms of the first, depend- 

 ent on the presence or absence of water and its depth. 



