Shakkk : Vascular Flora ol ALLKcjHiiw County. 103 



POPULUS Lini-ii^us. 



* P. alba Linnaius. Silver-leaf poplar. 



Escaped to roadsides. 



* P. tremuloides Michaux. American aspen. 



Harrison Township, between farms of John Potts and Jos. John- 

 ston, 1895-1900. 



* P. grandidentata Michaux. Large-toothed aspen. 



* P. balsamifera Linnaeus. Balsam poplar. 



* P. dilatata Linnaeus. Lombardy poplar. 



CERATOPHYLLACEiE A. Gray. 



HORNWORT FAMILY. IV-23. 



CERATOPHYLLUM Linnjeus. 

 t C. demersum Linnaeus. Hornwort. 



Pittsburgh, Silver Lake, 1885. C. C. Mellor. 



PINACE^ Li II d ley. 



PINE FAMILY, ll-i. 



PINUS Linnaeus. 



* P. Strobus Linnaeus. White pine. 



* P. Virginiana Miller. Scrub pine. 

 P. itiops Alton. 



TSUGA Carriere. 



* T. Canadensis (Linnaeus). Hemlock. 



JUNIPERUS Linnceus. 



* J. Virginiana Linnreus. Red cedar. 



