VALUE OF CHARACTERS. 871 
Cichoriaceee—the exceptions being 2 species in 465 in Vernoniaces, 
1 genus and some 10 or 12 stray species out of 1470 in Aste- 
roidez, about 20 species out of 1150 in Inuloideæ, about 6 in 650 
in Anthemidee, 10 in 115 in Calendulacez, 2 in 450 in Muti- 
siacez, and no exceptional opposite leaves known in Arctotidez 
250 species, Cynaroidew 880, or Cichoriaces 720 species. Alter- 
nate leaves are also prevalent in Senecionidez, but with nearly 10 
per cent. exceptional opposite ones (usually in distinet genera). 
In Helenioidez the opposite and alternate are rather more equally 
divided, the former being the more frequent ; and opposite leaves, 
at least in the lower part of the stem, are the rule in Eupatoriacee 
and Helianthoidex, although with several striking exceptions. 
Entire, toothed, or divided leaves may be respectively prevalent in 
tribes or genera, but rarely in a degree to be much relied on for a 
general character. The much-divided leaves, for instance, so 
common in Anthemidee are exceedingly rare in Vernoniacee, 
Eupatoriaces, and Inuloidee. The prickly-lobed foliage of so 
many Cynaroidez is scarcely to be met with elsewhere, except 
in a few Arctotidez (Gorteriex), one small genus of Cichoriacez 
(Scolymus), and here and there in monotypic genera scattered 
through other tribes. 
10. Differences in Habit, Stature, and General Inflorescence. 
In habit and stature, Composite are as variable as other large 
orders, without these differences being often even of generic im- 
portance, although they may sometimes give useful indications. 
Arborescent Composite are rare; and frutescent ones prevail only 
in comparatively few genera ; but in some cases these habits may 
assist in the discrimination of groups where more absolute cha- 
racters fail, especially when the differences are connected with 
geographical distribution. Thus in the great mass of Hetero- 
chromous Asteroidee and Conyres, including the large genera 
Aster, Erigeron, and Conyza, taken in their widest sense with a 
multitude of smaller genera around them, there is no one positive 
character to separate the groups, large or small, into which the 
six or seven hundred species have been distributed,—nothing 
absolute to separate Aster from Conyza, which nevertheless no 
experienced synantherologist would dream of uniting. Here, 
therefore, stature, combined with geographical distribution, have 
been appropriately called in aid by Weddell, excluding all the 
southern, usually frutescent, species from the northern, constantly 
