YALUE OF CHARACTERS. 365 
few genera among radiate Senecionidee or Inuloideee, and per- 
haps some others, where the ray-florets have at the base of their 
lamina one or two small inner lobes. 
In other respects the form of the florets may afford some slight 
indication of the genera or tribes. Long narrow corolla-lobes to the 
hermaphrodite regular floret (fig. 4) are characteristic of most Ver- 
noniacee and Cynaroidez, rare in Asteroidez, Inuloidex, Helian- 
thoideæ, and Senecionidew. The female florets when present are 
almost always slender, but regular or nearly so (fig. 8) in some genera 
or subtribes of Asteroidex, Inuloidee, Anthemidex, and Senecio- 
nidex, always ligulate (fig. 7) in others. Ina few genera or sec- 
tions of genera of Asteroidex, and in one of Mutisiacez, the outer 
rows of female florets are ligulate, the inner filiform ; and in some 
genera or subgenera of Helianthoides or Anthemidee the female 
florets have only a rudimentary corolla, or are absolutely without 
any. In all these respects differences in form of the corolla are 
more important than its absolute presence or absence, or than the 
degree of development when present. 
The general shape of the limb (that is, of the dilated portion above 
the insertion of the stamens) ofthe regular corolla, whether campan- 
ulate (fig. 3) or gradually dilated, or scarcely thicker than the tube 
and cylindrical (fig. 2), is sometimes characteristic of genera, but 
very frequently specific only. Colour is also, in some measure, 
characteristic of some tribes. The corollas are, I believe, never 
yellow in Vernoniacez or Eupatoriacex, and not very frequently 
so in Cynaroideee, in all of which the prevailing colour is purplish, 
varying from pink to blue, although pure blue is not frequent. In 
Cichoriacex yellow is the common colour, although some species, 
groups of species, or even genera are blue; pink and purple rare. 
In all the other tribes yellow is the prevailing and, in some tribes, 
the constant colour in the hermaphrodite florets ; pink, purple, and 
blue exceptional, the latter very rare. The female florets when 
expanded into a ray are either of the colour ofthe disk, or pink; 
purple, blue, or white, with a yellow disk. This distinction between 
homochromous and heterochromous flower-heads, although specific 
only in some genera, e. y. Senecio, is generic in Asteroides, where 
it has served indeed to characterize two of the subdivisions of the 
tribe—somewhat artificial ones it is true, but yet the best that 
have been proposed. White flowers are not common in the order, 
but are to be met with in all the tribes, whether the normal colour 
be yellow or not; they have even been made to serve as a generic 
