28 Flora of Rensselaer County, N. Y. 



These are common hybrids : lucida x fragilis ; cordata x sericea ; 

 cordata x petiolaris; alba x lucida; alba x 

 fragilis. 

 Populus alba, L. 



tremuloides, Mx. Asi-en. 

 grandidentata, Mx. 

 balsamitera, L. 

 monilifera, Ait. Northern Cottonwood. 



CERATOPHYLLACEiE. 

 Ceratophyllum demersum, L. 

 var. echinatum, Gr. 



CONIFERS. 

 Pinus strobus, L. Pine. 



rigida, Mill. Pitch P. 

 resinosa, Ait. 



Picea nigra, Link. Black Spruce. 



Tsuga Canadensis, Carr. Hemlock. 

 Abies balsamea, Mill. 

 Larix Americana, Mx. Tamarack. 

 Thuya occidentalis, L. Arbor-vit>e. 

 Juniperus communis, L. Cedar. 



Sabina, L., var. procumbens, Ph. 



Virginiana, L. 

 Taxus Canadensis, Willd. 



HYDROCHARIDACEiE. 

 Klodea Canadensis, Mx. 

 Valisneria spiralis, L. Eel-grass. 



ORCHID ACE^B. 

 Microstylis ophioglossoides, Nutt. E. Poestenkill, Wibbe. 

 Infrequent. 

 monopiiyllos, Lindl. Moul's Lake, Dr. Gordinier. Rare. 

 Llparis liliifolia, Rich. Oakwood, Howe, 1863; Prof. Puissant; 

 Hoag's corners, Wibbe. Infrequent. 

 Loeselii, Rich. Lansingburgh, Howe, 1863 ; Moul's Lake, Dr. 

 Gordinier. Rare. 

 Corallorhiza innata, R. Br. 



odontorrhiza, Nutt. W. Nassau, E. Poestenkill, J. H. 



Wibbe. Infrequent. 

 multif lora, Nutt. 

 Listera cordata, R. Br. Sphagnous swamp, Poestenkill, E. C. H. 



and elsewhere. Not common. 

 Spiranthes cernua, Rich. 

 gracilis, Bigel. 

 pra'COX, Wats. Oakwood, J. H. Wibbe. Very rare. 



