107 



Var. angustifolia. 



Pleasant pond, Wenham. 

 Var. gracilis. 



Georgetown (Mrs. Horner). 

 Sagittaria heterophylla, Pursh. 



Shore of the Merrimac, Lawrence, two miles above the dam, north 



side, Aug. 5, 1879 (J. R., etc.). 

 Sagittaria graminea, Michx. 



Borders of Wenham pond (J. E.). 

 Forma fluitans, Engel. 



With leaves two feet long collected in the Ipswich river by Mr. 



Sears. Similar specimens were found near Boston by Mr. E. H. 



Eitchings. 



HYDROCHAEIDACBiE. 



(Frog's-bit Family.) 



Anacbaris Canadensis, Planchon. (Water- Weed.) 

 Very common in some places, and undoubtedly to be found in the 

 county, but no specimens are in the P. A. S. collection. 



Vallisneria spiralis, L. (Vallisneeia.) 

 Frequent in ponds. A most interesting plant to study, the mode 

 of fertilization being very curious. 



ORCHIDACE^. 



(Orchis Family.) 



Orchis spectabilis, L. (Showy Orchis.) 

 Not known within the exact geographical limits of the county, 

 but growing quite near the line toward Chelsea, yet Dr. Bigelow 

 who botanized in that region does not mention it. 



Habenaria tridentata, Sook, 

 Essex, Beverly, Lynnfleld (A. P. Chute), Salem Great Pastures 

 (Tracy), Georgetown, Amesbury, North Andover. Scarce. 



Habenaria vireseens, Spreng. 

 Along brooks and in meadows, Georgetown (Mrs. Horner), etc. 

 Not very common. It Is quite probable that the species referred 

 to as 0. dilatata, Proc. E. I. Vol. II, p. 240, is either this or H. 

 lacera. 



Habenaria Hookeri, Torrey. 

 Found at Georgetown, June, 1874, by Mrs. Homer. It was ex- 

 hibited among other native plants in Boston, at the Mass. Hort. Soc. 

 rooms, at that date. 



