MIDDLESEX FLORA. 91 



URTICACE/E. NETTLE FAMILY. 



Ulmus, L. 



U. fulva, Michx. Slippery Elm. Red Elm. 



Concord (Walter Deane). Rare. Apr. 

 U. Americana, L. American Elm. White Elm. 



Common. Apr. 



Celtis, Tourn. 



C. occidentalis, L, including var. crassifolia. Sugarberrt. 

 Hackberry. 

 Lowell, Emerson's Trees and Shrubs of Mass. Apr.-May. 



MORUS, Tourn. 



M. rubra, L. Red Mulberry. 



Sparingly spontaneous. May. 

 M. ALBA, L. White Mulberry. 



Occasional; N. Billerica, along the old Middlesex Canal, among 



wild shrubs, itself shrubby (Dr. C. W. Swan) ; Concord, several 



trees (Miuot Pratt). May. Nat. from Eu. 



Urtica, Tourn. 



U. gracilis, Ait. Nettle. 



Common. July-Aug. 

 Urtica dioica, L. 



Pence-row, Watertowu (Walter Deane.) Nat. from Eu. 



U. URENS, L. 



Maiden (H. A. Young); Concord (Minot Pratt). Scarce. July- 

 Aug. Nat. from Eu. 



Laportea, Gaudich. 



L. Canadensis, Gaudich. Wood Nettle. 



Natick (Austin Bacon) ; Townsend (Dr. C. W. Swan) ; Belmont 

 (L. L. Dame). July-Aug. 



Pile A, Lindl. 



P. pumila, Gray. Richweed. Clearweed. 

 Rather common. July-Sept. 



Bcehmeria, Jacq. 



B. cylindrica, Willd. False Nettle. 

 Common. July-Aug. 



