102 MIDDLESEX FLORA. 



Sagittaria, L. 



S. variabilis, Eugelm. Arrow-head. 



Very common; including vars. obtusa and latlfolia, Engelm., 



Maiden (H. L. Moody) ; var. hastata, Eugelm., Cambridge (6. 



E. Davenport); var. diversifolia, Eugelm., Lowell (W. H. 



Manning) ; and var. angustifolia, Lowell (L. L. Dame). June- 



Aug. 

 S. calycina, Engelm. 



Medford (Wra. Boott, specimen in herb. of). July. 

 S. graminea, Michx. 



Cambridge and Arlington (C. E. Perkins) ; Framingham and 



Natick (Rev. Thos. Moroug) ; Medford (W. H. Manning). Aug. 

 S. graminea, Michx., var. fluitans, Engelm. 



So. Natick (Rev. Thos. Morong; specimen in herb. of). Aug. 

 S. natans, Michx. 



Westford (C. E. Perkins) ; Littleton (W. H. Manning). 



HYDROCHARIDACE.^. FROG'S-BIT FAIVIILY. 



Anacharis, Rich. 



A. Canadensis, Planch. Watp:r-weed. 



Somerville (Warner Bailey) ; Arlington (Wm. Boott) ; Fresh Pond, 

 Cambridge (Rev. Thos. Morong). July. 



Vallisneria, Mich. 



V. spiralis, L. Tape-grass. Eel-grass. 

 Common. July-Aug. 



ORCHIDACE>E. ORCHID FAIVIILY. 



Orchis, L. 



*0. spectabilis, L. Showy Orchis. 



Cambridge (T. W. Harris in Hovey's Mag., VI., 245). Concord, in- 

 troduced from Vermont by Minot Pratt. May. Very rare. 



Habenaria, Willd., R. Br. 



H. tridentata, Hook. 

 Common. June-Aug. 



H. vlrescens, Spreng. 

 Not uncommon. June-July. 



H. dilatata, Gray. 

 Lexington (Baldwin's Orchids of N. E.) ; Reading and Stoneham 

 (Wm. Boott, specimen in herb. of). The Concord plant was intro- 

 duced by Minot Pratt. June-July. 



