very distinct in the columnar structure, especially in the 
rostellum, from those found in Odontorhynchus. Moreover, in 
B. unilateralis the leaves are linear, fasciculate, whereas in O. 
variabilis they are always lanceolate to lanceolate-ovate and 
petiolate. 
The material available to me suggests that there are perhaps 
two or three different, closely related species hiding under O. 
variabilis, judging from the different terminal lobes of the lips 
and the coloration of the flowers. More field observations than 
are currently available are needed for the understanding of this 
complex. 
In herbarium material | was able to ascertain already that 
plants described as Spiranthes chilensis A. Rich. are indeed 
distinct from O. variabilis in the shape of the lip which 1s quite 
apparent also on Richard’s original drawing preserved in Paris. 
Pteroglossa luteola Garay, sp. nov. 
Plantae terrestres, elatae, usque ad 28 cm. altae; radicibus 
fasciculatis, stipitato-fusiformibus, elongatis pubescentibus; 
foliis basilaribus, e cuneata basi obovato-oblanceolatis, subpeti- 
olatis, obtusis, glabris, usque ad 23 cm. longis, 5.5 cm latis; 
scapo erecto, laxe plurivaginato, supra laxe paucifloro, usque ad 
28 cm. longo; bracteis foliaceis, ovato-lanceolatis, subacumi- 
natis, usque ad 2.5 cm. longis, 0.7 cm. latis; floribus conspicuis, 
pallide luteolis; sepalo postico lanceolato-oblongo, acuto, con- 
cavo, extus pubescenti, usque ad 18 mm. longo, 5 mm. lato; 
sepalis lateralibus oblique ellipticis, acutis, basi decurrentibus, 
extus breviter pubescentibus, usque ad 32 mm. longis, 7 mm. 
latis; petalis e cuneata basi oblique rhombeis, acutis, basi decur- 
rentibus, usque ad 23 mm. longis, 6 mm. latis; labello e cuneata 
basi obovato-oblanceolato, supra apicem sublobato, apice ipso 
reflexo, crenulato, basin margine calloso, usque ad 28 mm. 
longo, 10 mm. lato; columna plus minusque arcuata, facie 
puberula, basi longe decurrentia, usque ad 25 mm. longa: ovario 
fusiformi, subsessili, usque ad 25 mm. longo. 
Argentina: Estancia “Santa Teresa”, Depto. Mburucuya, 
Prov. Corrientes. Coll. Pedersen 8336! Type! (AMES). 
288 
