REGIONS AND AREAS OF DISTRIBUTION. 505 
Endemic Species in 
Euro 
North .__, |Extratro- pe : 
Genera and groupe of America, OPC) pical |, end, Tropical) South | Austra- 
senem. ingluding america. |, S082, mia" die | Africa. da. 
Aster type ......... 120 28 11 50 2 53 63 
Erigeron ......... 45 35 18 8 1 1 3 
Conyza cisco 3 4 3 2 20 8 2 
Pluchea ............ 7 5 aoe 1 10 sae + 
Gnaphalium ...... 18 20 18 10 12 8 6 
Coll 1 z: RA 6 1 20 8 
Senecio ............ 105 265 100 160 80 190 28 
Gerbera type...... 1 26 11 1 4 15 1 
Hieracium ......... 26 10 4 110 m 2 sa 
Of the above genera, Conyza, Pluchea, and, in a less degree, 
Gerbera have a rather tropical character; the others are more 
prevalent in temperate or mountain-regions. All, except Cotula, 
are endowed with means of dispersion which we should, primá 
Jacie, qualify as ready, the pappus spreading and light in propor- 
tion to the achene; but the ready colonizers (one, two, or three 
to a genus) belong to three or four only (Erigeron, Conyza, Gna- 
phalium, and perhaps Pluchea) of the eight pappose genera, or to 
Cotula, which has no pappus. Senecio is remarkable for the enor- 
mous number of locally restricted species, no one of them common 
to any two of the above regions, and not yet satisfactorily distri- 
buted into sections at once geographical and structural. Its only 
colonizer, S. vulgaris, is not classed here amongst the ready colo- 
nists ; for, as far as I can learn, although carried out into some 
distant lands with cultivation, it does not, like Erigeron canadense 
and others, establish itself over the country in waste and unculti- 
vated localities. The sections or divisions of Gnaphalium, Erige- 
ron, and Conyza are more marked than those of Senecio; but the 
principal ones are not geographical. Aster, Cotula, and Gerbera 
have established subordinate races, geographical as well as struc- 
tural, sufficiently distinct for us to have adopted them as genera. 
To the above genera might be added a few of very wide distri- 
bution, which, from Europe and northern Asia, spread round by 
North America and the Andes down to extratropical South Ame- 
rica and even to Australia, such as Centaurea, Hypocheris, Cnicus, 
&c.; but they appear to be better placed, as instances of extratro- 
pical northern connexions, in Table 5. To the same Table belongs 
also Hieracium, which I have added also to the present one on 
