1922] Flora of the Boston District, —XX X VI 155 
MONESES. 
M. uniflora (L.) Gray. Rich moist woods in Essex County (see 
J. Robinson, Fl. Essex Co. 74, 1880); also Reading, Stoneham, West- 
ford, Waltham and Natick. 
MONOTROPA. 
M. Hypopitys L. Rich woods, occasional. 
M. uniflora L. Damp woods, common. 
PYROLA. 
P. americana Sweet. Woods and open places, common. 
P.chlorantha Sw., var. convoluta (Barton) Fernald. See RHODORA 
xxii. 49, 1920. Freely distributed over the district in dry open woods 
as far south as Walpole, and probably throughout. 
P. elliptica Nutt. Woods, sometimes in the open; frequent, but 
not reported from southeastern towns. ~ 
P. rotundifolia L., var. americana (Sweet) Fernald. See RHODORA 
xxii. 122, 1920. Woods and open places, common. 
P.secunda L. Rich woods; occasional from Norwood and Hopkin- 
ton north and east. 
RHODODENDRON. 
R. canadense (L.) BSP. Swamps, frequent in Essex and Middlesex 
Counties, rare southward. 
R. canescens (Michx.) G. Don. Wooded banks of Jennings Pond, 
Natick (K. M. Wiegand, May 27, 1912); dry open woods, Wellesley 
Hills (Isaac Sprague, Jr., May 25, 1911); specimen in herb. Boston 
Soc. Nat. Hist. Reports of R. nudiflorum from the western towns 
in Dame & Collins, Fl. Middlesex Co. 63, 1888 are probably this species. 
R. maximum L. Wooded swamps at Medfield and Walpole. 
R.nudiflorum (L.) Torr. Purgatory Swamp. It has been collected 
between 1880 and 1897. 
R. VasEvr Gray. Persistent at old nursery site in Halifax and 
escaping into moist sandy woods (J. A. Cushman, C. H. Knowlton 
et al., May 30, 1907). A species from North Carolina. 
R. viscosum (L.) Torr. Swamps and wet woods, common through- 
out. 
R. viscosum (L.) Torr., var. glaucum (Michx.) Gray. Frequent 
with the typical plants. 
R. viscosum (L.) Torr., var. nitidum (Michx.) Gray. Low woods, 
Blue Hill Reservation (J. R. Churchill, June 28, 1914); Marshfield 
(J. R. Churchill & C. H. Knowlton, July 4, 1914). 
