452 MR. G. BENTHAM ON COMPOSITA. 
Anthemis or Achillea. Several species, usually of a somewhat 
shrubby growth, are natives of the Canary Islands, and two or 
three, also shrubby and somewhat anomalous, are South-African. 
But the circumscription of the genus is somewhat uncertain: 
some botanists divide it into about twenty genera, which may 
readily be distributed into five series; others, again, remove the 
greater part of the perennial species into Tunacetum. This, how- 
ever, does not much affect the group geographieally considered. 
Excepting the Canary-Island Argyranthema, the two or three 
larger series into which the genus might be divided have nearly 
the same range as the whole genus; and the numerous monotypic 
genera proposed belong chiefly toits great centre, the Mediterranean 
region. Richteria alone belongs to the mountain-region of Central 
Asia, where are also found two small genera, Addardia, four or five 
species, and the monotypic Cancrinia, which might almost have 
been included in Chrysanthemum, but for their pappus, which in 
both is exceptional in the tribe, showing an approach in the one 
case to that of Senecionide:, in the other to Helenioidew. One of 
the few South-African CArysanthema is, perhaps, a still further 
deviation from the ordinary type than the Canary-Island Argy- 
ranthema; but it has not been generically distinguished by the 
botanists who have worked out the Cape flora, and is not, perhaps, 
sufficiently known properly to appreciate its affinities. 
Matricaria, with about twenty species, has the wide range of 
Chrysanthemum, with, however, a southern preponderance—the 
perennial species with restricted areas belonging chiefly to South 
Africa, the northern species, chiefly annuals, having a very 
general distribution (partly as weeds of cultivation), two of them 
occurring in North, especially North-west America; two or three 
only of the more restricted species belong to the Mediterranean 
region. The twenty species have long been in a very unsettled 
state as to their systematic arrangement. Distributed into half 
a dozen small genera, or united in two only, severally associated 
some with Chrysanthemum, others with Tanacetum or Cotula, they 
are now generally recognized as forming one generie group, con- 
necting, as it were, Chrysanthemum with the Cotulex, differing 
from the former chiefly in the ribs of the achenes not equidistant 
round the achene, but more or less approximate towards the inner 
face, leaving a broader dorsal interval, and generally by their 
conical or elongated receptacle and the involucre approaching 
that of the Cotulee. In one species there is also a tendency to 
