462 MR. G. BENTHAM ON COMPOSITE. 
character, have no separate geographical areas; they are all 
Andine. 
There is, however, a tropical-African monotypic genus which 
technically would belong to Liabex rather than to any other sub- 
tribe, but appears to be almost as much isolated in its natural 
affinities as in its geographical position. This is Gongrothamnus 
from E. tropical Africa, enumerated by De Candolle as a species of 
Vernonia, but differing from the whole of that tribe in its yellow 
flowers and triplinerved leaves, besides that the style-branches, 
being minutely papillose and not hairy, are not strictly those 
of Vernoniacez. Its nearest affinities remain yet to be traced 
out. 
The subtribe Tussilagines, which, as well as the Liabex, we 
consider as more closely connected with Senecionidew than with 
any other tribe, belongs in its normal genera to the mountain or 
temperate regions of the northern hemisphere. These genera are 
usually placed amongst Eupatoriacee on account of a slight re- 
semblance in the style-branches ; but their heterogamous capitula, 
frequently yellow, remove them as far from Eupatoriaces as 
Liabes are from Vernoniacee; and here we have, moreover, the 
prevalence of a truly Senecionid involucre. The subtribe com- 
prises four genera of undoubted afinity— Tussilago a single species, 
Petasites about twelve, Homogyne three, and Cremanthodium four 
or five species; the first three, constituting the old genus Tussilago, 
are all European, and Homogyne exclusively so; the other two 
extend over Asia and N. America. Cremanthodium is Himalayan ; 
only one of its species has as yet been published, and has been re- 
ferred to Ligularia, of which, however, it has neither the habit nor 
the style; and its affinity to Tussilago is confirmed by other 
species. 
Here, again, we have three isolated genera, which we can only 
class artificially as connected with Tussilaginew». One is Luina, a 
single N.W.-American species, with something of the habit of an 
Inula, and, indeed, some approach to that genus in the almost 
setose points to the auricles of the anthers ; but these points or 
sete are exceedingly short, and scarcely more than observable in 
some Senecios. The involucre is that of Senecio, the style- 
branches between those of Inula and Tussilago, the geographical 
position very far removed from that of Inula, but quite within the 
range of Tussilaginem. Peucephyllum, another monotypic N.W.- 
American genus, referred by A, Gray with doubt to Eupatoriacee, 
