507 C. GLABRA Spach. (Pignut.) Common. 



508 C. coRDiFORMis Koch. (Bitternut.) Common in Abingtons. 



BETULACEAE (Birch Family) 

 CORYLUS L. (Hazelnut) 



509 C. AMERICANA Walt. (Hazelnut.) Common. 



510 C. ROSTRATA Ait. (Beaked Hazelnut.) Occasional. 



OSTRYA Scop. (Hop Hornbeam) 



511 O. VIRGINIAN A Koch. Common in rich woods. 



CARPINUS L. (Hornbeam, Ironwood) 



512 C. CAROLiNiANA Walt. (Blue or Water Beech.) Frequent along 



streams. 



BETULA L. (Birch) 



513 B. LENTA L. (Sweet or Black Birch.) Common. 



514 B. LUTEA Michx. (Yellow Birch.) Frequent. 



515 B. ALLEGHANiENsis Britton. Monroe County. 



516 B. NIGRA L. (River or Red Birch.) Frequent along rivers in two 



valleys. 



517 B. popuLiFOLiA Marsh. (White Birch.) Common. 



518 B. ALBA, VAR. PAPYRiFERA Spach. (Paper or Canoe Birch.) North 



slope of mountain at Chinchilla, near Elmhurst Boulevard 

 speedway. 



ALNUS Hill. (Alder) 



519 A. CRiSPA Pursh. (Mountain Alder.) Penobscot Knob. 



520 A. iNCANA Moench. (Speckled Alder.) Lower Lackawanna Valley, 



Moosic Mountain. 



521 A. RUGOSA Spreng. (Smooth Alder.) Frequent. 



FAGACEAE (Beech Family) 

 FAGUS L. Beech. 



522 F. GRANDiFOLiA Ehrh. Common in Abingtons. Not infrequent else- 



where. 



CASTANEA Hill. (Chestnut) 



523 C. DENTATA Borkh. Common. 



QUERCUS L. (Oak) 



524 Q. ALBA L. (White Oak.) Common. 



525 Q. BicoLOR Willd. (Swamp White Oak.) Above Leggett's Gap, Little 



Roaring Brook. 



526 Q. PRiNOiDEs Willd. Damp woods. 



527 Q. PRiNus L. (Chestnut Oak.) Frequent on mountains. 



528 Q. RUBRA L. (Red Oak.) Common. 



529 Q. cocciNEA Muench. (Scarlet Oak.) Frequent along Lackawanna. 



530 Q. VELUTiNA Lamb. (Black Oak.) Frequent. 



531 Q. iLiciFOLiA Wang. (Scrub Oak.) Common on rocky hills. 



30 



