270 BETULACEAE 



3. H. laciniosa (F. A. Michx.) Sargent. In rich soil: central 



N. Y. to Iowa and Neb. 



N. J. Reported but not definitely known from Mercer Co. 

 Pa. Recorded from Montgomery, Bucks, Berks, Philadelphia and 

 Delaware counties. 



Tertiary, o: Cretaceous, perhaps in Bucks Co., Pa.: Older 

 Formations, confined to eastern Pa. 176-204 days. Sea level- 

 624 ft. 



4. H. ovata (Mill.) Britton. Rich moist soil in valleys or occa- 



sionally on hillsides: Que. to Minn, and Kan., south to Fla. 

 Throughout the range, except in the pine-barrens of N. J. and 

 east and south of them, and on the coastal plain of L. I. ; apparently 

 always increasing northward. 



5. H. microcarpa (Nutt.) Britton. In rich woods: Mass. to 



Mich., south to Ga. and Mo. 



Conn. Occasional or frequent near the coast. 



N. Y. North shore of L. I.; S. I. increasing northward. 



N. J. Reported from Cumberland Co.; Bergen Co. 



Pa. Monroe, Northampton, Chester and Delaware counties. 



6. H. glabra (Mill.) Britton. Rocky woods and dry hillsides: 



Me. to Minn, and Kan., south to Fla. and Tex. 

 Conn. Throughout. 



N. Y. Throughout, increasing northward. 



N. J. Throughout the state, except the coastal strip, increasing 



and common northward. 

 Pa. Monroe, Northampton, Bucks, Philadelphia, Delaware and 



Chester counties. 



Tertiary, rare : Cretaceous, scattered : Older Formations, in- 

 creasing northward. 117-204 days. Sea level-1,000 ft. 

 H. villosa Ashe has been recorded from southern N. J. 



BETULACEAE 



Staminate flowers solitary in the axil of each bract, without a calyx; 

 pistillate flowers with a calyx. 

 Staminate flowers with no bractlets; pistillate aments spike-like; 

 nut small, subtended by or enclosed in a large bractlet. 

 Fruiting bract flat, 3-cleft and incised. ' 1. Carpinus. 



Fruiting bract bladder-like, closed, membranous. 2. Ostrya. 



Staminate flowers with 2 bractlets; pistillate flowers 2-4, capitate; 



nut large, enclosed by a leafy involucre. 3. Corylus. 



