186 
DIVISION OF COMPOUND FLOWERS. 
are arranged in one-sided racemes,-in another they form small and 
irregular clusters. The numerous species are in most cases so 
faintly distinguished, as to require some patienqe and application to 
trace out the specific differences. 
The genus Chrysanthemum contains the common daisy, some- 
times called ox-eye; it also includes many splendid foreign plants, 
mostly of Chinese origin. The Dahlia is at present a favourite with 
florists, who enumerate nearly a hundred splendid varieties. 
Order Frustranea. 
The third Order has the disk florets perfect; those of the ray 
are neutral^ having neither stamens nor styles, though an imperfect 
seed is sometimes seen at the base of the florets ; the name Frustra- 
nea alludes to this imperfect seed. We find here the Sun-flower, 
(Helianthus ;) this is a very good plant to examine, as the organs 
are large, and develop clearly the pecuhar character of the class 
Syngenesia. 
Fig. 143, a, represents the flower of the Coreopsis ; h, a floret ol 
the disk, with its bifid stigma above the tube formed by the united 
anthers; c, shows a ray floret, which is neutral. 
In this order is the Centaurea &e?2e(izc^a, or blessed thistle, a na- 
tive of Spain, which received its name on account of some extraor- 
dinary virtues which it was thought to possess ; it was esteemed a 
remedy for the plague, with which warm countries are often aSiict 
ed. At present this plant is not much valued in medicine. 
Order Necessaria. 
The fourth Order includes plants in which the rays only are fer- 
tile or pistillate, and the disk florets are barren or staminate. We 
find here the marygold, (Calendula.) 
Order Segregata. 
The flfth Order contains a few genera, with each floret having a 
calyx proper to itself, besides a common calyx including the whole 
of the florets which make up the flower; this may be called a 
doubly-compound flower. The only plant of this order yet discov- 
ered in the United States is the elephant 's-foot, (Elephantopus,) a 
low, hairy-leaved plant, with purple, ligulate florets. 
We have now completed a survey of the orders of the class Syn- 
genesia ; the plants which it contains are almost wholly referred to 
the natural order Compositae or compound flowers : by Jussieu, they 
are subdivided into the three following orders. 
Division of Compound Flowers by J2issieu. 
1st, with florets all ligulate and perfect ; leaves alternate, having 
milky juice; corollas mostly yellow. This includes the dandehon 
and lettuce. 
2d order includes all compound flowers with tubular corollas; with 
receptacles fleshy and chaffy; egret stiff" and bristly; leaves often 
with harsh prickles; flowers in a head. This includes the thistle, 
burdock, and false saffron. 
3d order includes such compound flowers as have their inflores- 
cence clustered in a corymb ; as the life-everlasting, boneset, and 
aster. 
The plants of the class Syngenesia are, in general, easily recog- 
nised at the first glance; there is something about them besides their 
Chrysanthemum — Dahlia— Order Frustranea— Sun- flower —Coreopsis— .Blessed 
thistle— Order Necessaria— Order Segregata— Elephant's foot— Order Compositae— 
Jussieu's division of compound flowers. 
