Flora Brasiliensis to Pleurothallis on the evidence of 
sketches, there being no specimens available for critical 
study. That these Brazilian species were aberrant is e- 
vinced by the fact that Cogniaux proposed for their re- 
ception the new section Lepanthopsis. Later, in Urban’s 
Symbolae Antillanae, Cogniaux recognized Pleurothallis 
anthoctenium Reichb.f., a West Indian species, as being 
referable to the alliance formed by the Brazilian species 
and he introduced the section Lepanthopsis in Symbolae 
Antillanae to receive P. anthoctenium. 
To establish generic boundaries in the Pleurothalli- 
dinae vegetative characters have proved to be without 
weight. The perianth has also proved inadequate as va- 
rious degrees of cohesion between the sepals, while relied 
on for generic distinction, have been found useless because 
of misleading exceptions. The only structure that is funda- 
mentally serviceable is the gynostemium, an organ that 
is desperately difficult to reconstruct and interpret when 
it has been crushed by the pressure used in preserving 
specimens forthe herbarium, although in living specimens 
it exhibits clearly marked characters which are service- 
able in differentiating major groups or genera. 
The gynostemium of Plewrothallis floripecten and P. 
anthoctenium is very unlike what obtains in P. ruscifolia 
(Sw.) R.Br., the type of the genus Pleurothallis. The 
receptive stigmas are widely separated (cf. plate of Le- 
panthopsis floripecten, fig. 4, the heavily stippled area) 
and at anthesis are not conspicuously confluent along the 
frontal margin of the clinandrium beneath the rostellum 
as in P. ruscifolia; at the base the gynostemium is apo- 
dal, and at the summit conspicuously dilated with the 
posterior margin of the clinandrium cucullate. In P. rus- 
cifola the gynostemium is more or less elongated, cylin- 
drical with a pulvinate foot, and an obliquely truncate 
apex. The stigmatic lobes of P. floripecten are suborbi- 
[2] 
