Evans: TAXILEJEUNEA PTEROGONIA 113 
bear the incorrect name O. apiculatus Gottsche in the Lindenberg 
Herbarium. Stephani has since cited 7. pterogonia from Chenim 
de Carillo, Costa Rica, Pittier 6064.* In 1913 he described the 
habitat of the species as, ‘‘ America tropica, valde communis,’’t 
but this scarcely seems warranted from the scanty records in 
the literature. 
The writer, as already noted, has recently recorded T. ptero- 
gonia from San Miguel, Peru, but regrets that he has been unable 
to confirm any of the other published records for the species. 
The large series of specimens listed above has, however, been 
available for study and this has included named material from 
Ecuador in Spruce’ s Exsiccatae (not alluded to in his book) and 
named material from Colombia in the Mitten Herbarium. This 
material and the other specimens listed clearly represent the same 
specific type. 
In describing a variable species it is always difficult to do 
justice to its range of variability and at the same time to distinguish 
it clearly from its allies. This is strikingly the case with T. ptero- 
gonia and other members of this difficult genus. When fertile 
and well-developed specimens are examined their specific char- 
acters seem to be above question, but marked variations are often 
encountered, even in a single plant, and tend to obscure the 
specific limitations. These variations affect particularly the size 
and vigor of the plants, the form and marginal features of the 
leaf-lobes and underleaves, and the characters derived from the 
involucral leaves and underleaves. In the case of sterile material 
a positive determination is always difficult and may be quite 
impossible. 
According to Stephani the stems of T. pterogonia sometimes 
attain a length of 10 cm. In the writer’s experience they rarely 
surpass 4 cm. in length, although a greater development would 
not be surprising. Stephani’s measurements of the leaves and 
underleaves are likewise a little high and must have been drawn 
from unusually vigorous plants. According to his description 
the leaves are 1.67 mm. long and 1.33 mm. wide, while the under- 
leaves measure IX 1.33 mm. Spruce gives I1.1x1I mm. for the 
* Bull. Soc. Roy. Bot. Belgique 31: 180. 1892. 
t Spec. Hepat. 5: 476. 1913. 
