124 ORCHIDACE^ 



ered a near relative of S. vernalis, is not unlike typical S. odorata; 

 it was compared by him with supposed S. vernalis, but the mate- 

 rial in the herbarium of the New York Botanical Garden labelled 

 S. vernalis (which I have studied) proves to be S. odorata erro- 

 neously determined. 



The distribution of species as given below is entirely based on 

 specimens examined by me in the preparation of this synopsis. 

 For the loan of material I am chiefly indebted to Dr. B. L. Rob- 

 inson of the Gray Herbarium, to Dr. N. L. Britton of the New 

 York Botanical Garden, to Professor WiUiam Trelease of the Mis- 

 souri Botanic Garden, to Mr. C. D. Beadle of the Biltmore Herba- 

 rium, to Dr. J. N. Rose of the National Herbarium, and to the 

 following gentlemen who have kindly placed their own herbaria 

 or those of the institutions with which they are identified, at my 

 disposal ; viz.. Professor Samuel M. Bain, Mr. C. H. Bissell, Dr. 

 E. H. Eames, Mr. 0. A. Farwell, Mr. M. L. Fernald, Mr. E. B. 

 Harger, Mr. F. Tracy Hubbard, Mr. C. N. Lochman, Professor 

 C. V. Piper, Mr. E. A. Rau, Mr. J. Reverchon, Professor L. M. 

 Umbach, Mr. S. Hart Wright. 



KEY TO THE SPECIES 



Flowers forming a single rank, often secund. 



Leaves rarely persistent, ovate or elliptic, lamina rarely exceeding 4.5 cm. in length. 

 Root solitary (or sometimes apparently of two tubers, the tuber of the past year 

 persisting). 



Lip quadrate, white. 1. S. Beckii. 



Roots fasciculate. 



Lip quadrate, green-centred. 2. S. gracilis. 



Leaves fugacious or persistent, oblong-lanceolate to linear-lanceolate, some of them 

 exceeding 4.5 cm. in length. 



Basal leaves mostly wanting during anthesis. 



Lip oblong-quadrate ; flowers spirally secund. 3. S. tortilis. 



Lip tapering to the obtuse tip ; flowers secund, hardly spiral. 



4. S. longilabris. 

 Leaves mostly persistent. 



Lip oblong, sometimes from a broadened nearly quadrate base, shorter than 



the sepals and petals, laciniate at the tip, broadest where the callosities 



arise, pubescent beneath. 5. <S. laciniata. 



Lip ovate to ovate-oblong, usually equalling the sepals and petals ; not 



laciniate at the tip, broadest in front of the callosities, pubescent beneath. 



6. S. vernalis. 



