KOBINSON. — STUDIES IN THE EUPATORIEAE. 17 



II. Revision of the Genus Ophryosporus. 



Ophryosporus is a natural but not sharply delimitable group of 

 South American Eupatorleae Piqnerinae. It differs from Piqueria 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 Eupatorium. 

 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 Eupatorium. Ophryosporus may be di- 

 vided into two sections (scarcely of subgeneric rank) on the nature of 

 the inflorescence and arrangement of the leaves. The t}^)ical 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 tyi^es or authentic specimens of all the species and 

 varieties of the genus as here treated. 



OPHRYOSPORUS Meyen. (Nomen ab 6<f>pv^, supercilium, et o-Tropa', 



seineu, derivatum, achaeniis in costis saepissime ciliatis.) — Capitula 



homogama parva numerosa paniculata vel th}TSoidea 3-12-flora plus 



minusve pedicellata ; involucri anguste campanulati vel cylindrici, 



squamis subaequalibus 1-2-seriatim laxe vel vix imbricatis, disco nudo 



parvo leviter convexo. Corollae albae tubulosae sursum gradatim ampli- 



atae vel in fauces distinctos dilatatae externe praesertim in tubo proprio 



et sub apicibus dentium glanduloso-puberulae vel atomiferae; limbi 



dentibus 5 brevibus triangulares patentibus. Filamenta gracilia glabra. 

 VOL. xLn. — 2 



