Flora of Vermont 189 



L. cordata (L.) R. Br. Heart-leaved Twayblade. Sphagnum bogs and 

 mossy mountain woods; frequent. 



MICROSTYLIS. (MALAXIS). Adder's Mouth 



M. inoiiopbjilos (L.) Lindl. White Adder's Mouth. Swamps and 



mountain cliffs; rare. 

 M. uuifolia (Michx.) BSP. (M. ophiglossoides Eaton). Green Adder's 



Mouth. Open woods; occasional. 



ORCHIS 



0. rotnndifolia Banks. Cold cedar swamps of northern Vermont; rare. 



Monkton, Bristol, and Starksboro, (Pringle). 

 0. spectabilis L. (Galeorchis spectabilis [L.] Rydb.). Showy Orchis. 



Rich moist woods of the lower altitudes; common. 



POGONIA 



P. affinis Aust. (Isotria affinis [Aust.] Rydb.). Small Whorled Pogo- 

 nia. Burlington, one plant, (Mrs. Holt). 



P. ophiogiossoides (L.) Ker. Rose Pogonia, Snake-mouth. Bogs; fre- 

 quent. 



P. triaiitliophora (Sw.) BSP. (P. pendula Lindl.; Triphora triantho- 

 phora [Sw.] Rydb.). Nodding Pogonia. Dry woodlands. Fair 

 Haven, (Chandler) ; Newfane, (Howe and Grout) ; Westminster, 

 Putney, (W. H. Blanchard). 



P. yerticillata (Willd.) Nutt. (Isotria verticillata [Willd.] Raf.). 

 Whorled Pogonia. Colchester, (Robbins, Torrey) ; Pownal, (An- 

 drews, Grace G. Niles) ; Burlington, (F. A. Ross). 



SPIRANTHES. (IBIDIUM). Ladies' Tresses 



S. cernua (L.) Richard. Nodding Ladies' Tresses. Wet soil; com- 

 mon. Var. ochroleuca (Rydb.) Ames. Hartland, (Nancy Darling). 



S. gracilis (Bigel.) Beck. Slender Ladies' Tresses. Sandy woods and 

 plains; occasional. 



S. lucida (H. H. Eaton) Ames. (S. latifolia Torr. ; I. plantagineura 

 [Raf.] House). Wet gravelly shores; occasional. 



S. Roiiianzoffiaua Cham. (I. strictum [Rydb.] House.). Bogs and cold 

 moist soil; occasional. 



SALICACEAE. WILLOW FAMILY 



POPULUS. Poplar. Aspen 



P. alba* L. White Poplar. Silver-leaved Poplar. Frequent in cultiva- 

 tion and an occasional escape. 



P. balsaiiiifera L. Balsam Poplar, Tacamahac. Borders of streams 

 and swamps; frequent. 



P. candicaus* Ait. Balm of Gilead. Occasional in cultivation and 

 sometimes spontaneous. 



