378 ROSACEAE 



25. R. Enslenii Tratt. Mass. to Mo., Tex. and southeastward. 



So far as now known, on L. I., the Bronx and Westchester 

 County, N. Y.; reported also from the coastal plain of N. J. 



Hybridizes with R. Baileyanus, procumbens, flagellaris, fron- 

 dosus, argutus and hispidus. 



26. R. nigricans Rydb. In low ground: Newf. to R. I., Pa. and 



Wise. 



Nearly throughout the range, except in the pine-barrens; there 

 rare or wanting; rare in the region immediately surrounding the 

 pine-barrens; not known on S. I. 



Hybridizes with R. frondosus, sativus, nigrobaccus, recurvans, 

 pergratus, canadensis, Randii, plicatifolius, Baileyanus, procumbens 

 and hispidus. 



27. R. setosus Bigel. Mass. to Conn, and N. Y. 



Known in our area only from a doubtful specimen from South- 

 ington, Conn. 



28. R. hispidus L. Low grounds and wet meadows: N. S. to Ga., 



Mich, and Minn. 



Common throughout the range. 

 Hybridizes with R. canadensis, nigrobaccus, frondosus, Bailey- 

 anus, plicatijolius, flagellaris, Enslenii and nigricans. 



R. Linkianus Ser., a European species has been collected, but not recently, near 

 Camden, N. J. 



21. Dalibarda L. 

 1. D. repens L. On dry or rocky hills: N. B. to the Rocky Mts., 

 south to Tenn. and Kan. 

 Conn. Northwestern Litchfield Co. 

 N. Y. The Mountains of Ulster, Sullivan, Greene and Delaware 



counties. 

 N. J. Reported from Swedesboro, Gloucester Co.; otherwise 



unknown.* 

 Pa. Monroe, Luzerne, Carbon, Lackawanna and Schuylkill 

 counties. 



Tertiary, 0: Cretaceous, a single extra-limital station.* Older 

 Formations: increasing northward. 1 17-189 days. Sea level- 

 4,050 ft. 

 Alchemilla arvensis Scop, has been reported from the area as a waif. 

 * See Introduction, paragraph 36. 



