STELIS GRACILIS 



Stelis gracilis Ames Orchid ace^, Fasc. ii. p. 266 (1908). 



Secondary stems erect or ascending, 2-4 cm. long, clothed by 

 elongated ancipitous obliquely truncate acute sheaths^ which are 

 conspicuously nervose when dry. Leaves coriaceous, linear-ob- 

 long, bidentate at the tip, 6-10 cm. long, 7-10 mm. wide above 

 the middle, tapering at base into slender canaliculate petioles. 

 Peduncle longer than the leaf, 10 cm. long, filiform, graceful, 

 clothed at interv^als with tubular obhquely truncate aristate- 

 apiculate bracts, about 1 mm. long. Pedicels gi-aceful, slender, 

 exceeding the scale-like ^o?Ti/ bracts. Flowers minute. Sepals 

 similar, ovate, 3-nerved, 2 mm. long, 1.5 mm. wide. Petals 

 cuneate, fleshy, thickened at the apex, about 0.5 mm. long, 

 1 mm. wide near the tip, 1 -nerved. Labellum unguiculate, sub- 

 equal to the petals, at about the middle obscurely bicallose, the 

 calli approximate or confluent. Column short, the margin den- 

 tate. 



Guatemala : Cubilquitz, Depart. Alta Verapaz, at 350 m. alt., June, 1900, 

 H. von Tuerckheim (no. 7681). 



In habit Stelis gracilis resembles S. intermedia Poepp. &; Endl. 

 The callus on the labellum appears to be variable and is so mi- 

 nute that its presence is not readily detected. 



The genus Stelis, of Swartz, is systematically a most confusing 

 one; consequently it is very inadequately understood and as a 

 rule very poorly represented by carefully determined specimens 

 in herbaria. Until an exhaustive comparative study of all avail- 

 able material has been made it must prove a fruitless task to 

 identify with surety any but the better known and more common 

 species of the genus. 



[74] 



