ROBINSON, — STUDIES IN THE EUPATORIEBAE. 17 
II. Revision or tHE Genus OpuHRyosPorvs. 
Ophryosporus is a natural but not sharply delimitable group of 
South American Hupatorieae Piquerinae. It differs from Pigueria in 
the presence of a well developed barbellate or shortly plumose pappus 
of numerous capillary or rarely slightly thickened bristles. From 
Eupatorium it differs in the entire absence of the apical appendage of 
the anthers and usually may be distinguished furthermore by its sub- 
simple involucre and rather conspicuously enlarged tips of the style 
branches. The boundary between the two genera has been variously 
drawn and must be regarded at best as a somewhat artificial line. To 
the writer it appears that if the genus Ophryosporus is to be maintained 
at all it must be restricted to those species in which the anthers are 
really destitute of any terminal appendage or trace of such a structure 
in any perceptible broadening or thickening of the connective at its 
summit. Close examination shows such rudimentary appendages in 
several species which recent authors have referred to Ophryosporus, 
plants which furthermore exhibit at least in some instances the more 
imbricated involucre and less enlarged style tips usual in Lupatorium. 
If these species were kept in Ophryosporus there would appear to be 
no single valid character and no combination of characters by which 
the two genera could be clearly divided. For this reason it seems best 
to refer these plants again to Hupatorium. Ophryosporus may be di- 
vided into two sections (scarcely of subgeneric rank) on the nature of 
the inflorescence and arrangement of the leaves. The typical section 
is Chilian, while the other and larger section has a wider distribution, 
occurring in Brazil, Argentina, Chili, Peru, Bolivia, and Ecuador. 
Most of the species of Brazil and Argentina are, so far as yet known, 
rather local. Those of the Andes, on the other hand, in some cases 
have a considerable north and south range. The writer has been able 
to examine the types or authentic specimens of all the species and 
varieties of the genus as here treated. 
OPHRYOSPORUS Meyen. ( — ab ddprs, supercilium, et oropd, 
semen, derivatum, achaeniis in costis saepissime ciliatis.) — Capitula 
homogama parva numerosa paniculata vel thyrsoidea 3-12-flora plus 
minusve pedicellata ; involucri anguste campanulati vel aan 
squamis subaequalibus 1-2-seriatim laxe vel vix im imbrieatis, disco 
parvo leviter convexo. 
atae vel in fauces distinctos dilatatae externe ere tai 8 ra 
et sub apicibus dentium glanduloso-puberulae vel atomiferae ; limbi 
egos 5 Eaervibes triangulares patentibus. Filamenta gracilia glabra. 
