90 MIDDLESEX TLORA. 



C. demersum, L., var. echlnatum, Graj-, 

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



CALLITR1CHACE>^. WATEE-STAEWOET FAMILY. 



Callitriche, L. 



G. verna, L. Water Starwort. 



Common. May-July. 

 C. heterophylla, Puish. 



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



Pond (Wm. Boott). May-July. 



PODOSTEMACE/E. RIVER-WEED FAMILY. 



PODOSTEBION, Michx. 



P. ceratophyllus, Michx. River-weed. 

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



EUPHORBIACEv^. SPURGE FAMILY. 



Euphorbia, L. 



E. maculata, L. 



Very common. July-Sept. 

 E. hypericifolia, L. 



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



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

 E. corollata, L. Flowering Spurge. 



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



West. 

 JC. 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. 



