1915] Flora of the Boston District,— XX. 169 
REPORTS ON THE FLORA OF THE BOSTON 
DISTRICT,— XX. 
URTICACEAE. 
BOEHMERIA. 
B. cylindrica (L.) Sw. Wet places, common, but not reported 
from the southwest. 
CANNABIS. 
C. sativa L. Waste places; occasional, especially around cities. 
CELTIS. 
C. occidentalis L. Woods and pastures, also on seashore; along 
the coast from Plum Island to Duxbury, also at Lowell, Lexington, 
Concord, Lincoln, South Sudbury, and Waltham. 
HUMULUS. 
H. saponicus Sieb. & Zucc. A Japanese species, escaped in waste 
places at Salem and Peabody (J. H. Sears, Oct. 5, 1904), Weston 
(according to M. L. Fernald), Roxbury (G. G. Kennedy, Oct. 9, 1907), 
and at Scituate (Edward W. Cushman). 
H. LvPvLvs L. Roadsides and waste places, evidently introduced 
in our territory. Reported from many stations. 
LAPORTEA. 
L. canadensis (L.) Gaud. Rich woods, rare; Groveland, Boxford, 
Belmont, Brookline, Natick, Cohasset. 
MACLURA. 
M. pomirera (Raf.) Schneider. Escaped on Page St., Danvers 
(G. G. Kennedy, Aug. 20, 1907). Introduced from the west. 
