Page:An introduction to physiological and systematical botany (1st edition).djvu/483

 Rh * Discoid, the florets of the margin being obsolete or inconspicuous, from the smallness or peculiar form of the corolla; as Artemisia, ''Engl. Bot. t. 338, 978, 1230; Tanacetum, t. 1229; Conyza, t. 1195; and Gnaphalium, t.'' 267, 1157. In the last the marginal florets are mostly 5-cleft and tubular like the rest, only wanting stamens. Caution is requisite to detect the difference between this section and the preceding Order.

** Ligulate, 2-lipped, of which Perdicium, a rare exotic genus, is the only instance.

*** Radiant, the marginal florets ligulate, forming spreading conspicuous rays; as Bellis the Daisy, t. 424; Aster, t. 87, a very numerous genus in America; Chrysanthemum, t. 601, 540; Inula, t. 1546, &c. This section seems, at first sight, a combination of the first and third sections of the former Order, but this is chiefly in the form of its corollas. It is rather an approach of that third section towards what is equivalent to becoming double in other tribes. Accordingly, the Chamomile, Anthemis nobilis, t. 980; Chrysanthemum Leucanthemum, t. 601; and