78 THE FLOWERING PLANT. 
the result, common examples of which are wild plantain and 
wheat. Varieties of spike are the spadia (fig. 33), with fleshy 
axis (e.g., arum), and the amentum or catkin, with scaly bracts, 
as seen in willow and hazel. 
(2.) We now come to cases of simple racemose inflorescences, 
where, by suppression of internodes, the main axis remains 
extremely short. Imagine a telescoped raceme. ‘The pedicels 
would all start very close together from the abbreviated axis, 
looking, so to speak, like the ribs of an umbrella turned inside 
out. Such an inflorescence is an wmbel, as seen in ivy. Its 
nature may be known by the centripetal way in which the flowers 
open. In a case like this, the bracts, from the axils of which the 
pedicels arise, if they do not disappear altogether, are crowded 
into an involucre or circlet. The capitulum or head is what we 
should get if a spike were telescoped, or if the flowers of an 
umbel became sessile or nearly so. The axis is here more or 
less dilated, and may be rounded, conical, or globular in shape. 
Common red and white clover are good examples, and the bracts 
are here readily seen. A further interesting point about clovers 
is the fact that among the numerous species we find all gradations, 
from short spikes (crimson clover, a cultivated form) down to 
well-marked heads. The stumpy axis is often called receptacle, 
but must not be confounded with the floral receptacle. The 
extremely large and important family of Composites, including 
daisy, dandelion, sunflower, thistle, &c., &c., is characterized by 
the possession of heads. Take, for instance, a daisy. A beginner 
would very likely mistake the white part for a corolla, and a lot 
of little green leaves outside this for a calyx, 
but would then be puzzled by the yellow 
centre. We have, in fact, not a single 
flower, but a very large number, crowded 
into a head, and often termed, from their 
small size, florets. They can easily be picked 
off the receptacle, and it is not difficult to 
} make out the nature of the central ones which 
compose the yellow “disk.” ‘The white ‘ray ” 
is made up of somewhat modified florets. The 
apparent calyx is an involucre made up of the 
FIG. 34.—Section of Fig. outer bracts. It can easily be seen that the 
non teceptacle. » florets open centripetally. In thistle, dande- 
ze lining the ]jon, and groundsel the florets are all alike. 
The fig is a modified head bearing florets on 
the inner side of a thickened hollow common receptacle (fig. 34). 
Compound racemose inflorescences have their branches, of secon- 
dary or higher order, constructed on one or more of the types 
