IRbofcora 



JOURNAL OF 



THE NEW ENGLAND BOTANICAL CLUB 



Vol. 23. April, 1921. No. 268. 



NOTES ON NEW ENGLAND ORCHIDS,— I. 

 SPIRANTHES. 



Oakes Ames. 



(Plates 127-129) 



Spiranthes, as limited in the most recent monograph of the Spir- 

 anthea 1 , 1 includes only those species that are characterized by a 

 spiral arrangement of the flowers. Thus limited, the genus attains 

 its highest development in the United States. It is the only large 

 amphigean orchid genus in our flora that has a preponderance of its 

 recognized representatives in the range covered by Gray's New 

 Manual, Small's Flora of the Southeastern United States and floras 

 devoted to the vegetation of our western coast. 



Among the twenty-four genera proposed as components of the 

 Spirantheae, the genus Spiranthes is set apart by the spiral arrange- 

 ment of flowers in which the lateral sepals are free to the base and not 

 decurrent on the ovary and in which the short column is character- 

 ized by a bent tip and an abbreviated foot. With the exception of 

 Spiranthes, the genera of the Spiranthea? are confined to the New 

 W'orld. Whether or not we can permanently exclude from Spi- 

 anthes such species as Spiranthes cranichoides Cogn. now referred to 

 Cyclopogon, and Spiranthes eriophora Robins. & Greenm. now re- 

 ferred to Schiedeella, is a debatable question. 



Spiranthes is the most perplexing orchid genus in our flora. It is 

 the least understood and the one that furnishes to authors who grow 

 impatient under the restraints imposed by cautious progress, the best 



' K. Sehlechter in Bciheftc zum Bot. Centralbl. XXXVII (1920), Abt. II, 318- 

 454. 



