No. 14.] FLOWERING PLANTS AND FERNS. 1 33 



Pogonia verticillata (Willd.) Niitt. (whorled). 

 Isotria verticillata Raf. 

 Whorled Pogonia. 



Rare or occasional. Rich woods. Mid-May — early June. 



Pogonia affinis Austin (allied). 

 Isotria affinis Rydb. 

 Smaller Whorled Pogonia. 



Rare. Rich woods: New Haven (E. S. Dana), Stratford 

 (C. K. Averill, Eames). Mid-May — mid-June. 



CALOPOGON R. Br. 



Calopogon pulchellus (Sw.) R. Br. (pretty). 



Limodorum tuberosum of American authors, not L. 

 Grass Pink. Calopogon. 



Occasional or frequent. Bogs and low meadows. June — 

 July. 



The flowers are rarely pure white. 



ARETHUSA L. 



Arethusa bulbosa L. (bulbous). 

 Arethusa. 



Rare or local. Sphagnum bogs and wet meadows. Late 

 May — June. 



SPIRANTHES Richard. Ladies' Tresses. 



Spiranthes Beckii Lindl. 

 Spiranthes simplex Gray. 

 Gyrostachys simplex Kuntze. 



Rare or local. Dry, sandy fields and sterile pastures. Aug. 

 — Sept. 



Spiranthes gracilis (Bigel.) Beck (slender). 

 Gyrostachys gracilis Kuntze. 



Frequent. Fields, meadows and open woods, in both moist 

 and dry ground. Aug. — Sept. 



Spiranthes vernalis Engelm. & Gray (vernal). 

 Spiranthes praecox Gray's Manual ed. 6 in part. 

 Gyrostachys praecox Kuntze. 

 Gyrostachys linearis Rydb. 



