1909] Flora of the Boston District,— V. 205 
Newbury (J. Robinson, Aug. 13, 1879); shallow water, common, 
Ponkapaug Pond, Canton (J. R. Churchill, July 26, 1884). This 
species probably occurs sparingly throughout. 
S. diversifolium Graebner. Bogs and muddy shores, Beverly, 
Sharon, Stoneham, Concord, Wellesley, Natick, Framingham, Hyde 
Park, Quincy and Randolph. 
S. diversifolium Graebner, var. acaule (Beeby) Fernald & Eames. 
See RHODORA, x. 56. 1908. “In running water in inuddy-sandy 
brook. ‘The station (where the plants are rather plenty) is in a warm 
open meadow. Near State Muster Grounds, South Framingham" 
(A. J. Eames, Sept. 7, 1907); Bridgewater (E. W. Sinnott, September, 
1908). 
S. eurycarpum Engelm. Muddy shores and shallow water, fre- 
quent. 
S. fluctuans (Morong) Robinson. Ponkapaug Pond, Canton 
(J. R. Churchill, July 26, 1884); in two feet of water, Whitehall Pond, 
Woodville, Hopkinton (T. Morong, Sept. 15, 1887). 
S. lucidum Fernald & Eames. Small pond, pasture, close to the 
road, Medford (Wm. Boott, July 29, 1860. One of the type specimens 
in Gray Herb.); very abundant on muddy shore of Heard Pond, 
Wayland (A. J. Eames & C. H. Knowlton, Sept. 6, 1909). 
S. minimum Fries. Spot Pond, Middlesex Fells, in good fruit 
(Wm. Boott, Aug. 31, 1854. Specimen in Gray Herb.); Waushakum 
Pond, Ashland (T. Morong, July 14, 1881; Aug. 7, 1883; Sept. 5, 
1887. "Does not fruit here freely, but propagates more by root- 
stocks.) 
NAJADACEAE. 
NAJAS. 
М. flexilis (Willd.) Rostk. & Schmidt. Shallow water of ponds or 
slow streams, on sandy or muddy bottoms, common throughout. 
Collected in Spot Pond, Stoneham, by Wm. Boott, Aug. 31, 1854. 
N. flexilis (Willd.) Rostk. & Schmidt, var. robusta Morong. “In 
four feet of water, reaching nearly to the surface, Sudbury River, 
Concord" (T. Morong & W. Deane, Aug. 4, 1886). 
N. gracillima (4. Br.) Magnus. Ponds; North Andover, Stoneham, 
Winchester, Woburn, Mystic Pond. Collected in Winchester by Wm. 
