90 MIDDLESEX FLOE A. 



C. demersum, L., var. echinatum, Gray. 

 Cambridge, specimen in herb. B. S. N. H. 



CALLITRICHACE^E. WATEK-STAKWOKT FAMILY, 



CALLITRICHE, L. 



G. verna, L. WATER STARWORT. 



Common. May-July. 

 C. heterophylla, Pursh. 



Ashland (Rev. Thos. Mororig) ; Maiden (H. A. Young) ; Spot 



Pond (Wm. Boott). May-July. 



PODOSTEMACE^E. RIVER-WEED FAMILY. 



PODOSTEMON, Michx. 



P. ceratophyllus, Michx. RIVER-WEED. 

 In the Charles River, So. Natick (Edwin Faxon). July-Sept. 



EUPHORBIACE^E. SPURGE FAMILY. 



EUPHORBIA, L. 



E. maculata, L. 



Very common. July-Sept. 

 E. hypericifolia, L. 



Lowell (Dr. C. W. Swan) ; Concord (Minot Pratt)-; Framinghain 



(Rev. J. H. Temple). Rare. July-Sept. 

 E. corollata, L. FLOWERING SPURGE. 



Lowell, " dump " (Dr. C. W. Swan). July-Sept. Adv. from the 



West. 

 E. Esula, L. 



Somerville (C. E. Perkins); Waltham List. Rare. June. AdV. 



from Eu. 

 E. CYPARISSIAS, L. CYPRESS SPURGE. 



Common. May-June. Nat. from Eu. 



ACALYPHA, L. 



A. Virginica, L. THREE-SEEDED MERCURY. 

 Common. July-Sept. 



