124 , MIDDLESEX FLORA. 



Cenchbus, L. 

 C. tribuloides, L. Hedgehog Grass. Bur Grass. 

 Dracut and Chelmsford, in the yicinity of woollen mills (Dr. C. 

 W. Swan). Possibly introduced here, though it is native in this 

 region. 



Spaetina, Schreh. 



S. cynosuroides, Willd. Fresh-water Cord Grass. 



Lowell (Dr. C. W. Swan) ; Concord (E. S. Hoar) ; and common 



near salt water. 

 S. juncea, Willd. Eush Salt Grass. 



Common near salt water. 

 S. stricta. Roth, var. glabra, Gray. Salt Marsh Grass. 



Common near salt water. 

 S. stricta. Roth, var. alterniflora. Gray. 



Medford (Miss A. M. Symmes) ; Cambridge (C. E. Perkins). 



ZlZANIA, L. 



Z. aquatlca, L. Indian Rice. Water Oats. 

 Not uncommon. 



Leersia, Sol. 



L. Virginica, Willd. White Grass. 

 Tewksbury and Lowell (Dr. C. W. Swan) ; Belmont and Medford 

 (C. E. Perkins) ; Waltham List. Damp woods ; not common. 



L, oryzoides, Sw. Rice Cut Grass. 

 Common. 



Andropogon, L. Beard Grass. 



A. provincialis. Lam. (A. furcatus, Muhl., Man.) 



Not uncommon. 

 A. scoparius, Michx. 



Common in dry places. 

 *A. dissitiflorus, Michx. (A. Virginicus, L., Man.) 



Waltham List; also reported in the county, but without precise 



location, by H. A. Young. Rare. 



Chrtsopogon, Trin. 



C. nutans, Benth. (Sorghum nutans. Gray, Man.) Indian 

 Grass. Wood Grass. 

 Occasional. 



Phalaris, L. 



P. Canariensis, L. Canary Grass. 

 Not uncommon in waste places. It yields the Canary seed, and its 

 constant recurrence in waste heaps Is thus accounted for. Adv. 

 from En. 



