490 
MR. G. BENTHAM ON COMPOSIT X. 
in the character of the Composite of the two divisions than can 
be attributed to any climatological or other physical causes ; and 
the difference is still more striking in the species, of which only 
63 out of a total number of nearly $400 are common to the New 
and the Old World; and these common ones are chiefly either 
Alpine or high northern, where the general flora is more continu- 
ous, or ready colonizers, although their presence in the two divi- 
sions cannot be attributed to recent colonization. 
These genera and species common to the two divisions require 
separate consideration, according as they are tropical, northern, or 
southern. 
Table 3. Tropical connexion between America and the Old World 
as indicated by identical or closely allied Genera and Sections 
without identical Species. 
Genera. 
Tropical-American representatives. 
Tropical Old-World representatives. 
CENTRATHERUM 
Connexions 
VERNONIA. 
Representative 
Sections. 
Diverging sections 
Connexions 
ERIGERON 
Conyza. 
Identical groups 
Diverging groups 
Connexions 
PLUCHEA. 
Representative 
2 widely spread species, extending 
southward of the tropics, and one of 
them reappearing in Australia. 
Oiospermum, a closely allied mono- 
type, otherwise those of Vernonia. 
Hololepis 2 species. 
Ef ve Sy about 200 species, a few 
of which extend beyond the tropics 
both north and south. 
Critoniopsis 6 species. 
hal, 
Leiboldia, St 
, Trianthea, 
and Eremosis, all small Columbian 
or Mexican sections. 
Ha yy 24 species, Piptolepis 8 
Sp. and Albertinia, Vanillosmopsis, 
Blanchetia, Lachnorhiza, and Bola- 
nosa, all monotypic, immediately 
connected with Vernonia; and 17 
genera with above 80 species rather 
more remote. 
See northern connexions, Table 5, 
Dimorphanthes, Cass., or genuine Co- 
nyze, represented by C. chilensis and 
ies. 
Lennecia ( C. gnaphalioides and allies), 
C. triplinervia and allies, 
Erigeron (Cenotus) more northern, 
and in the tropics Nidorella and 
Psiadia, on the one hand, Laggera, 
Blumea, Pluchea, and smaller ones 
on the other. 
P. purpurascens and allies. 
4 Asiatic species, differing perhaps 
sectionally from the American ones. 
None nearer than Vernonia. 
V. calycina, Wall, in Asia, and V. 
purpurea, Sch. Bip., in Africa. | 
Gymnanthemum about 20 species, 
Asiatie and African, and perhaps 
a few Asiatic true Lepidaploe. — 
Strobocalyx about 20 species, Asiatic 
E Qe : 
ipholepis about 12 species, Cyanopts 
about "0 eet Pioda cbout 20 
Species, all with the majority 
Asiatie, but also several African | 
species. Lepidella 15 species and 
Stengelia 14 species, exclusively 
ican, or nearly so. 
Bothriocline in Africa, Adenoon and 
Lamprospermum in Asia, Pleuro- 
carpea in Australia, and Centaurop- 
sis in Madagascar, all — 
and immediately connected, and 4 
genera with about 9 species rather 
more remote. 
Dimorphanthes, represented by C. 
egyptiaca and allies. 
Marginate (C. Gouani and allies), 
Fimbrillaria ( C. ivefolia and allies). 
Erigeron (Cenotus), more northern ; 
and in the tropics Baecharis on the 
one hand, and Pluchea and allies on 
the other. 
P. tomentosa and allies. 
