94 ROBINSON 
has never had a generic diagnosis, and the International Rules for 
Botanical Nomenclature are explicit in their statement that a genus 
is not validly published by the mere mention of species (even of 
previously described species) as belonging to it. 
However, the writer has no wish to deprive Kuntze either of his 
generic name Sphaereupatorium or of the specific combination S. 
Hoffmannii. The point at issue is the one from which Kuntze by his - 
ambiguous phrases desired to escape responsible decision, namely 
whether the plant is or is not of generic rank. 
Happily Kuntze’s original material is now in the herbarium of the 
New York Botanical Garden and has been lent to the writer for study. 
In its general habit there is nothing to exclude the species from the 
large and multiform genus Eupatorium. Even the so-called heads of 
a secondary order form no fundimental difference; for, at several 
other points in Eupatorium, species occur in which the individual 
heads are essentially sessile in subglobose glomerules, as, for instance, 
E. glomeratum DC. of Peru, E. pseudoglomeratum Hieron. of Ecuador 
and Colombia, E. acuminatum HBK. of Colombia, and even the 
highly peculiar E. monanthum Sch.-Bip. of Mexico. 
If one stopped, as the German investigators obviously did, at a 
very superficial examination of the plant, it would certainly appear 
unworthy of generic separation; but careful dissection discloses a 
character of much greater significance, for the receptacles in the in- 
dividual heads are regularly chaffy throughout their entire extent. 
Not only is this trait one of considerable importance in separating 
Composite genera, but it has already been employed as a differential 
character in distinguishing certain eupatorioid genera. It seems 
unwise to extend the diversity and add to the already cumbersome 
size of the genus Eupatorium, when distinctions of this definiteness 
and general significance can be found for separation. Accordingly, 
to put the genus Sphaereupatorium on a more regular footing, its 
characters may be here stated in a brief diagnosis. : 
Sphaereupatorium (O. Hoffm.) Ktze. gen. nov. Eupatoriearum- 
Ageratinarum. Capitula homogama. tubiflora in glomerulos globosos 
paniculatos arcte congesta. Involucrum campanulatum, squamis 
subaequalibus. Receptaculum parvum planum ubique paleaceum. 
Corollae regulares aequales, limbo 5-dentato. Antherae apice ap- 
pendiculatae basi obtusae. Styli rami elongati filiformes | leviter 
clavulati longissime exserti. Achaenia 5-angulata. Pappi setae 
capillares numerosae simplices—Eupatorium § Sphaereupatorium O. 
Hoffm. in Engl. & Prantl, Nat. Pflanzenf. Nachtr. 322 (1897). Sphaer- 




