FLORA OF \yASHINGTON AND VICINITY. 119 



HYDRO CHARID ACEiE. 



Frog's-bit Family. 



Anacharis Canadensis, Planchon. Watkr-weed. 

 Juno. 



tVallisneria spiralis, L. Tape-grass. Eel-grass. 

 July. 



ORCHIDACEiE. 



Orchis Family. 



t Orchis spectabilis, L. Showy' Orchis. 

 May. 



t Habenaria tridentata, Hook. Rein-Orchis. 



August. 



Habenaria virescens, Spreng. Green Rein-Orchis. 



Hunting Creek ; Eastern Branch Marsh ; rare. Third week in June, 

 t Habenaria ciliaris, R. Br. Yellow Fringed Orchis. 



A single specimen found July 21, 1878, by Prof. M. H. Doolittle, near the Reform 

 School. Not since seen. 



f Habenaria lacera, R. Br. Ragged Fringed Orchis. 



Very rare ; found July 3, 1874, near Boundary and Sixteenth streets, July 12, 1879, 

 in the Terra Cotta region, and June 22, 1881, in Corcoran's Woods ; a single speci- 

 men in each case, the last in good condition. 



t Goodyera pubescens, R. Br. Rattlesnake-Plantain. 

 June or July. 



Spiranthes latifolia, Torr. Broad-leaved Ladies' Traces. 



A single specimen found May 12, 1878, on the flats below Chain Bridge. 



t Spiranthes cernua, Richard. Drooping-flowered Ladies' Traces. 

 Last of Sejitember. 



t Spiranthes graminea, Lindl., var. Walteri, Gray. Grass-leaa^^d Ladies' Traces. ■ 

 September. 



Spiranthes gracilis, Bigelow. Slender Ladies' Traces. 



Spikes apparently always twisted in the direction of aright-handed screw. Root 

 leaves usually gone at flowering time, but found still present with the flowers July 

 4, 1879, at Great Falls. July to September. 



Spiranthes simplex, Gray. 



Spikes sometimes twisted to the right and sometimes to the left. Pine woods 

 near Bladensburg ; rather rare. September. 



tPogonia ophioglossoides, Nutt. Snake-Mouth. 



A form having leaves 4*=™ wide was found in the Holmead Swamp, June 13, 1880. 

 First half of June. 



tPogonia verticillata, Nutt. Whorled Snake-Mouth. 

 Third or fourth week in May. 



