DISTRIBUTION OF TRIBES. 451 
them from both. Between Anthemidex and Helenioidee (Euhe- 
leniez) there is, perhaps, no very definite boundary ; but generally 
the habit, involucre, or geographical distribution, accompanied by 
various minor indications, do not leave much doubt as to the 
position of a genus. 
In the ‘Genera Plantarum’ we have, for convenience’ sake, 
classed the genera somewhat artificially. In considering their geo- 
graphical distribution we must adopt a different sequence, taking :— 
first the great northern genera Anthemis and its allies, Chrysan- 
themum, Tanacetum, and Artemisia, some of which extend a few 
species into North America; then the South-African Athanasia, 
Hippia, and their allies, all restricted to that region; thirdly, the 
Cotulee, which are more cosmopolitan, belonging in a great 
measure to the southern hemisphere ; and, lastly, a few isolated 
local genera. 
Anthemis, above eighty species, Anacyclus, about ten species, 
Achillea, near 100 species, Santolina, about eight species, and the 
monotypic Cladanthus, Diotis, and, perhaps, Lonas and Mecomiscus; 
separated from each other by characters of no great importance, 
besides habit, are distinguished from Chrysanthemum by their 
paleaceous receptacle. The two larger genera, Anthemis and 
Achillea, range over Europe, North Africa, and extratropical Asia, 
their chief centre being the Mediterranean region and the Levant. 
One species, the common Achillea millefolium, appears to be 
spread over the whole of Europe, northern and central Asia, and 
a great part of North America, where are also mountain species of 
the same genus. But no Anthemis is to be met with in America 
or in the southern hemisphere except as weeds of cultivation. 
Santolina and Anacyclus are limited to the Mediterranean region 
taken in arather wide sense. Cladanthus is a West-Mediterranean 
plant; Diotis a maritime species extending along the greater part 
of the European and African coasts, around the Mediterranean, 
and along the Ocean from the Cape to the British Islands. Meco- 
miscus is an Algerian plant, exceptional in the tribe on account of 
its leaves opposite and entire as in the southern Eumorphia and 
GZdera. 
Chrysanthemum, taken in the extended sense we have given it 
in the ‘Genera Plantarum,’ includes above eighty good species, and 
has nearly the same range as the Anthemis group. It has, however, 
fewer mountain species than Achillea, and extends only into the 
extreme north of America ; southward it reaches much further than 
