HOFFMANN: FLORA OF BERKSHIRE COUNTY. 285 
Occasional on dumps; WilHamstown ; North Adams. 
P. serotina Ehrh. Black Cherry; Rum Cherry. — {Padus 
virginiana 111. Fl. ed. 2.) 
Rich woods and roadsides; common. Altitude 1800 feet, Savoy; 
2600 feet, Greylock. 
P. virginiana L. Choke Cherry. — (Padus nana 111. Fl. ed. 2.) 
Roadside thickets, fence-rows, borders of woods and mountain- 
tops; common. Summit of Greylock, 3400 feet. 
PYRUS. Apple; Pear. 
P. americana (Marsh) DC. American Mountain Ash. — 
(Sorbus americana 111. Fl. ed. 2.) 
Open woods; common on the upland. Borders of cool swamps in 
the valley. 
P. arbutifolia (L.) L. f., var. atropurpurea (Britton) Robinson. 
Red Chokeberry. — {Aronia afropurimrea 111. Fl. ed. 2.) 
Swamps and borders of bogs; frequent in the southern part of the 
valley. Rocky hillside, Monterey. Specimens with 12- to 14-fruited 
cymes from Sheffield (Churchill). 
P. COMMUNIS L. Pear. — Occasionally self-sown in pastures and 
woodland. 
P. Malus L. Apple.— (Mains mains 111. Fl. ed. 2.) 
Roadsides and woods; common. 
P. melanocarpa (Michx.) \Yilld. Black Chokeberry. — (Aronia 
melanocarpa III. Fl. ed. 2.) 
Dry rocky or sandy soil, hillside pastures on the plateau, and in 
swamps and bogs; common. 
X P. PRUNiFOLiA Willd. Crab Apple. — Roadside escape, Shef- 
field. 
P. sitchensis (Roem.) Piper. — (Sorbns scopulina 111. Fl. ed. 2.) 
Occasional on Greylock; Hancock (Bean). 
According to Dr. Rehder (in lit.) P. sitchensis (Roem.) Piper is a 
species of the Pacific Coast, and the New England species is Sorbus 
decora Schneid. 
ROSA. Rose. 
R. blanda Ait. — Dry open woods, roadside thickets and borders 
of streams; occasional. Greylock, altitude 2500 feet; Stockbridge; 
West Stockbridge; Sandisfield; New Marlboro; Sheffield. 
