454 PROCEEDINGS OF THE AMERICAN ACADEMY. 
Species reducta vel exclusa. : 
A. Armani (Balbis) Bak. in Mart. Fl. Bras. vi. pt. 2, 191 (1876). 
Eupatorium Armani Balbis, Pl. Rar. Hort. Turin, 1810, p. 27, 
t. 6 (1810). Orsinia Eupatoria DC. Prod. v. 104 (1836). Pi- 
queria Eupatorium (DC.) Gardn. in Hook. Lond. Jour. Bot. vi. 
430 (1847). Clibadium rotundifolium DC. Prod. v. 505 (1836); 
Bak. 1. ¢. vi. pt. 3, 152 (1884), ubi syn. alia..= Ci1papruM ARMANI 
(Balbis) Sch. Bip. ex Bak. 1. c. (1884). 
A. polyphylla (Sch. Bip.) Bak. = A. rasticiaTa (Gardn.) Benth. 
A. spilanthoides D. Don ex Hook. & Arn. Comp. Bot. Mag. i. 238 
(1835) = GyMNocoRONIS sPILANTHOIDES (D. Don) DC. Prod. 
vii. 266 (1838). 
2. REVISION OF THE GENUS AGERATUM. 
The genus Ageratum L. has not been subjected to any general revi- 
sion since its treatment in DeCandolle’s Prodromus in 1836. For 
many years it has been made to include plants of a considerable range 
of habit and, what is more noteworthy, though chiefly defined by its 
pappus, has been allowed to contain species of widely divergent 
character in just this matter. While the more typical species have @ 
pappus of five distinct scales, others have a cup-like crown of very 
short and connate scales; still others have been admitted into the 
genus which instead of scales of definite number have short or long, 
slender or slightly thickened, smooth or plumose bristles of indefinite 
number ranging from 8 to 20 or more. Finally certain species have 
been included from similarity of habit which possess no true pappus 
whatever but merely a sort of annulus beneath rather than exterior 
to the corolla 
To render the genus properly natural and compact, as well as to 
permit its more precise definition, it seems best to refer to Alomia the 
species destitute of pappus, and to exclude also those species which 
have a bristle pappus. The latter group consists of six South Amer!- 
can species, namely A. Agrianthus Hoffm. (Agrianthus corymbosus 
DC.), A. alternifolium (Gardn.) Bak., A. campuloclinioides Bak., A- 
confertum (Gardn.) Benth., A. melissaefolium DC., and A. Pohlianum 
Bak. At first, it seemed likely that these species could be approp!- 
ately separated as a distinct genus. Schultz-Bipontinus seems 
have planned such a segregation in his undescribed Melissopsts. : 
species, however, differ much among themselves, both as to habit 
