1911] Flora of the Boston District,— X 83 
were pointed out, and two or three of the varieties are local forms not 
very frequent anywhere. This leaves about twelve which are dis- 
tinctly rare in our section. A few of these are northern, but several 
of them seem to be stragglers from the pine-barren region further south. 
There is no reason why a careful search of the district should not 
reveal other ponds as rich as Winter Pond and Heard’s Pond, but thus 
far the quest has not been successful. There are still numerous 
unexplored ponds in the district, and a large number just south of our 
borders. The questions of distribution raised by such facts as are 
stated here are most interesting, and should lead to more field work. 
CYPERACEAE. 
SCIRPUS. 
S. americanus Pers. Mud and gravel near salt and fresh water. 
Abundant in eastern half of district, but only one station (Wayland) 
reported in western towns. 
S. atrocinctus Fernald. Bogs and swales. Unreported from 
southeastern section, but fairly common elsewhere. 
S. atrocinctus Fernald, var. brachypodus Fernald. Salisbury 
(A. A. Eaton, 1898); Amesbury (A. A. Eaton, Aug. 28, 1897); Read- 
ing (C. E. Perkins, July 12, 1882). 
S. atrovirens Muhl. Andover (A. S. Pease, July 21, 1901); moist 
soil, Westford (W. H. Manning, ^ug. 9, 1882); Medford Branch R. R., 
Medford (Wm. Boott, July 23, 1867); field, Medford (Wm. Boott, 
July 12, 1868); damp woods, Moose Hill, Sharon (W. P. Rich, July 
12, 1896). 
S. campestris Britton, var. Fernaldi (Bicknell) Bartlett. Kern- 
wood, Salem, some specimens over five feet high (J. Robinson, July 27, 
1879); banks of Mystic River, Medford (Wm. Boott, Aug. 23, 1859). 
S. campestris Britton, var. novae-angliae (Britton) Fernald. 
Salt marsh, Ipswich (J. H. Sears, Aug. 24, 1886); Somerville (C. E. 
Perkins, Aug. 26, 1879); Watertown (C. E. Perkins, July 17, 1880); 
shallow water in brackish marsh, Scituate (W. P. Rich & E. F. 
Williams, Sept. 8, 1901). : 
S. campestris Britton, var. paludosus (A. Nelson) Fernald. 
Salt marshes, abundant along the coast. 
S. cyperinus (L.) Kunth. Swamps and shores of ponds. Not 
