204 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 



PICEA. Spktjce. 



P. mariana (Mill) BSP. Bog Spruce; Black Spruce. — Peat 

 bogs; occasional. Adams (Knowlton & Bean) ; Ward Pond, Becket; 

 Wolf Swamp, Sandisfield. In the last two localities the Spruce is the 

 host for Dwarf Mistletoe (Arceuthobium) . 



P. rubra (DuRoi) Dietr. Red Spruce. — (P. rubens 111. Fl. ed. 2.) 



Rocky summits on the plateau; occasional in the valley, (a few 

 trees in a swamp in Stockbridge). Some fine timber still left on Grey- 

 lock. 



forma virgata Rehder. — WiUiamstown (Walker). 



Differs from the type by the long and slender branches entirely 

 destitute of branchlets {vid. Rhodora, 9: 110, 1907). 



PINUS. Pine. 



P. resinosa Ait. Red Pine; Norway Pine. — Rocky woods; 

 rare. Summit of Tom Ball, Alford; Stockbridge. 



P. rigida Mill. Pitch Pine. — Sandy soil; frequent in Sheffield, 

 occasional in Stockbridge, New Marlboro, Sandisfield, Great Barring- 

 ton; summit of The Dome, Mt. Washington. 



P. Strobus L. White Pine. — In almost every soil and situation; 

 common. Young pines grow up in the shelter of Hardback (Poten- 

 tilla fruticosa) and gradually kill it out. 



P. STLVESTRis L. ScOTCH PiNE. — An occasional escape from 

 cultivation. Lanesboro (Walters). 



THUJA. Arbor Vitae. 



T. occiDENTALis L. Arbor ViTAE; White Cedar. — Commonly 

 planted and occasionally spreading. Although Arbor Vitae has been 

 found native in Connecticut and New York, in localities close to Berk- 

 shire Co., no native trees have been discovered in the County. 



TSUGA. Hemlock. 

 T. canadensis (L.) Carr. Hemlock. — Rocky woods; common. 



TYPHACEAE. CAT-TAIL FAMILY. 

 TYPHA. Cat-tail. 



T. angustifolia L. — Borders of swamps; rare. Stockbridge; 

 Sandisfield. 



