An examination of mature buds from the Ames isotype reveals 



that there are eight unequal pollinia in the anther, not two as 



reported by Royen, confirming his original placement of this 



species in the Thelasiinae. There are five species in Octarrhena 



which share with O. bilabrata the eight unequal pollinia and the 



unusual protruding column, but which differ in habit, having 



long multiflowered inflorescences. 



PNG, Eastern Highlands Prov., Goroka Subprov., near Keri- 



gomna camp, 3000 m., Hoogland & Pullen 5525 (AMES!, L! 



Isotypes). 



The following key is offered to differentiate the species related 

 to Octarrhena bilabrata: 



1. Inflorescences short, 4 8 mm long, I 3-flowered O. bilabrata 

 la. Inflorescences longer, 2-9 cm in length, many-flowered ... 2 



2. Lip adnate to column pouch in lower half . . O. calceiformis 

 2a. Lip free from column 3 



3. Lip linear-ligulate O. cucullifera 



3a. Lip broader, ovate, oblong or triangular 4 



4. Inflorescence I, subterminal, peduncle long, ovary smooth to 

 slightly rugulose O. obovata 



4a. Inflorescence(s) I many, axillary from any part of stem, 

 peduncle short, ovary warty 5 



5. Leaves 8-15 mm long, petals obtuse to truncate. . .0. gracilis 

 5a. Leaves 17-25 mm long, petals acute O. cupulilabra 



Octarrhena teretifolia (Gilli) Kittredge, comb, now 



Basionym: Dendrochilum teretifolium Gilli, Ann. Nat. Mus. 



Wien84B:31, 1983. 



This species is closely allied to O. arfakensis J. J. Sm. and O. 

 cylindrica J. J. Sm. from which it differs in having orbicular 

 petals and an invagination at the apex of the lip calli. 

 PNG, Western Highlands Prov., Laiagam, 2850 m., Gilli 461 (W! 



Holotype). 



Thelasis abbreviata (Schltr.) Kittredge, comb, now 



Basionym: Oxyanthera abbreviata Schltr., Fedde, Rep. Beih. 



1:906, 1913. 



101 



