494 
MR. G. BENTHAM ON COMPOSITE. 
Species. 
Area. 
Congeners. 
Connexions. 
Bidens pilosa and B. bi- 
pinnata. 
Synedrella nodiflora........ 
Chrysanthellum.............. 
Enhydra (several names, 
probably one species). 
Cosmopolitan, tropical | 
and subtropical 
(ready colonists). 
America, Asia, and 
Africa, tropical 
(ready colonist). 
America, Asia, 
Africa, tropical. 
and 
America, Asia, Africa, 
and Australia, tropi- 
cal (semiaquatic). 
| 1 tropical-American 
About 40 cosectional 
Chiefly American, with & 
species, all tropical | few African. 
American; a distinct 
section,amphigeous 
and extratropical. 
species. 
1 tropical-American 
(Galapagian). 
2 or 3 tropieal-Ame- 
rican species. 
Chiefly American, with a 
few African, besides the 
following. 
ltropical-Asiatic mono- 
type (Glossocardia) and 
I tropica] - American 
(Heterospermum), _the 
further ones chiefly 
American. 
None immediate; 
nearest American. 
the 
rio, 
Cotula coronopifolia.........| Europe, South Africa, | About 35 Old-World | A few small allied genera 
Australia, extratropi- | species, chiefly chiefly South-African, 
cal South America. South - African, 2| Australian, New Zea- 
> South-American. land, and extratropical 
or Andine, 1 Ameri- 
can. 
Centipeda orbicularis(My-| South Africa, Aus- | 1 Australian (and 1 | Same as Cotula. 
e minuta and M. 
tralia, New Zealand, 
elatinoides). 
extratropical South 
erica, 
African ?) species. 
We have here, as in the first list, a marked American prepon- 
derance; for, with the exception of Chrysanthellum, Cotula, and 
Centipeda, the connexions are exclusively, or almost exclusively, 
American. It is possible, indeed, that the Ageratum, the Sieges- 
beckia, the two Bidens, and even the Synedrella may be of 
comparatively modern introduction, and may belong therefore 
rather to the class of species of which the interchange between 
various regions is now going on. The Ambrosia also as a maritime 
plant may have been brought over at any time. The Spargano- 
phorus, the Enhydra, and perhaps the Epaltes belong to the class 
of semiaquatic plants whose wide diffusion and ready dispersion 
to great distances have been frequently observed, although, 
perhaps, not yet satisfactorily accounted for. Xanthium spinosum, 
long known in the Old World, but which has only very recently 
taken possession of Australia, is here omitted, as being believed 
by many to be only a modern colonist in the Old World. But 
the .Elephantopus, Adenostemma, Mikania, Eclipta, Xanthium 
strumarium, and Chrysanthellum, besides the above-mentioned 
Enhydra and Epaltes, give strong presumptive evidence of a 
prehistoric establishment in the Old World, not, perhaps, ancient 
enough to have settled down into distinct species, but having 
most of them already produced more or less marked varieties, 
which may be considered as incipient species, to be further 
