APPENDIX. 



Ostrya Virginiana (Mill.) Willd. Iron-wood. In dry woods. 



Corylus Americana Walt. Hazel-nut. In thickets. 



Corylus rostrata Ait. Beaked Hazel-nut. On rocky hillsides. 



Betula populifolia Marsh. American White Birch. Near Bristol, I. C. Martindale; 



Springfield, Dr. J. J. Ott; Morrisville, Dr. E. Newlin Williams; Bensalem. 

 Betula nigra L. River Birch. Red Birch. Along streams. 

 Betula lenta L. Sweet Birch. In woods and thickets. 

 Alnus rugosa (DuRoi) K. Koch. Smooth Alder. In wet soil. 



Family 2. Fagaceae Drude. 



Fagus Americana Sweet. American Beech. In rich soil. 



Castanea dentata (Marsh.) Borkh. American Chestnut. In rich soil. 



Quercus rubra L. Red Oak. In rich soil. 



Quercus palustris DuRoi. Pin Oak. Swamp Oak. In moist ground. 



Quercus coccinea Wang. Scarlet Oak. In dry soil. 



Quercus velutina Lam. Black Oak. Quercitron. In dry soil. 



Quercus digitata (Marsh.) Sudw. Spanish Oak. In dry soil. 



Quercus nana (Marsh.) Sarg. Scrub Oak. In dry or rocky soil. 



Quercus Marylandica Muenqh. Black-jack. Along the Delaware in the lower end; 



Perkasie. 

 Quercus Rudkini Britton. Rudkin"s Oak. Tullytown, Joseph Crawford. 

 Quercus Phellos L. Willow Oak. Near Bristol. 

 Quercus alba L. White Oak. In rich, moist soil. 

 Quercus minor (Marsh.) Sarg. Post Oak. Iron Oak. Carversville. 

 Quercus platanoides (Lam.) Sudw. Swamp White Oak. In moist soil. 

 Quercus Prinus L. Rock Chestnut Oak. In dry soil. 

 Quercus prinoides Willd. Scrub Chestnut Oak. Barrens of Plumstead and Nock- 



amixon, (M. C). 



Order 6. URTICALES. 



Family i. Ulmaceae Mirbel. 



Ulmus Americana L. American White or W^ater Elm. In moist soil. 

 Ulmus fulva Michx. Slippery, Red or Moose Elm. In wood and on hills. 

 Celtis occidentalis L. Sugar-berry. On dry ground. 

 Celtis crassifolia Lam. Hackberry. Near Sellersville. 



Family 2. Moraceae Lindl. 



Moras rubra L. Red Mulberry. In rich woods. 

 Morus alba L. White Mulberry. Escaped, in a few places. 

 Humulus Lupulus L. Hop. Native along streams. 

 Cannabis sativa L. Hemp. In waste places, occasionally. 



Family 3- Urticaceae Reichenb. 



Urtica dioica L. Stinging Nettle. In waste places. 



Ui;tica gracilis Ait. Slender Nettle. In rich soil. 



Urticastrum divaricatum (L.) Kuntze. Wood Nettle. In rich woods. 



Adicea pumila (L) Raf. Clearweed. Richweed. In wet, shaded places. 



Boehmeria cylindrica (L.) Willd. False Nettle. In moist situations. 



