392 AMYGDALACEAE 



Leaves glabrous; pedicels short; fruit 



sour. 8. P. Cerasus. 

 Leaves pubescent, at least on the veins; 



pedicels long; fruit sweet. g. P. Avium. 



Native tree; flowers corymbose; leaves acute. 10. P. pennsylvanica. 



Flowers appearing after the leaves. II. P. Mahaleb. 



1. P. alleghaniensis Porter. In woods: E. Conn., and eastern 



Pa. Rare in our range. 



Known definitely in our area only from a few stations in southern 

 Conn. 



2. P. maritima Wang. On sea-beaches and in sandy soil near the 



coast: N. B. to Va. 



Common throughout our sea beaches and along the shores of 

 L. I. Sound and N. Y. Bay. Also on the coastal plain of N. J. and 

 L. I. 



3. P. Gravesii Small. On a gravelly ridge: Eastern Conn. 



Known only from its original locality at Groton, Conn. 



4. P. americana Marsh. (P. americana mollis T. & G.). In woods: 



N. Eng. to Mont., Fla. and Colo. 



Conn. Rare over most of the state. 



N. Y. Rare on L. I. and S. I. and up the Hudson Valley to the 

 Highlands, not reported northward. 



N.J. Unknown in the pine-barrens, rare in the region surrounding 

 them, increasing northward. 



Pa. Luzerne, Northampton, Bucks, Delaware and Chester coun- 

 ties. 



Tertiary, not on Beacon Hill, rare elsewhere: Cretaceous, scat- 

 tered: Older Formations, increasing northward. 138-220 days. 



Sea level-1,800 ft. 



5. P. angustifolia Marsh. In dry soil: N. J. to Fla., west to the 



Rocky Mts. 



Known definitely only from Salem Co., N. J., a region on the 

 Cretaceous sands and gravels, with a growing season of 179 days 

 and about at sea-level; perhaps not native. 



6. P. pumila L. On sandy or gravelly shores or in sandy woods : 



N. B. to Man., N. J. and Mich. 



Conn. Rare and local in the northwestern part of the state. 

 N. Y. Unknown on L. I. or S. I., rare in Westchester Co., thence 

 increasing and common northward. 



