POPULAR FLORA. 165 
in most cases, these flowers have a strap-shaped corolla. This will be understood by sup- 
posing a long tubular corolla to be split down on one side and spread out flat. In the 
Cichory (Fig. 402), Dandelion, and the like, all the flowers are strap-shaped. But in Sun- 
flower, Coreopsis (Fig. 404), 
Aster, and many others, only 
the flowers round the margin 
are strap-shaped ; these are 
called rays or ray-flowers, and 
at first view much resemble 
the petals of a: many-petalled 
blossom, — all the more so, be- 
cause in Coreopsis and Sun- 
flower these ray-flowers are 
neutral, having neither sta- 
mens nor pistils, But in As- 
ters and Daisies, they are pis- 
tillate, having a pistil only. 
The blossoms, which in these 
cases fill the body of the head, 
and are so small that the su- 
perficial observer is apt to 
; take them for stamens or pis- 
tils, are regular and perfect, with a tubular and 5-lobed corolla (Fig. 405 a). They are 
called disk-flowers. In Thistles, Thoroughwort, Wormwood, and some kinds of Ground- 
sel, all the flowers are 
of this sort, i. e. there 
are no rays, but all 
the flowers tubular. 
In all, the ovary is 
one-celled and one 
seeded, and makes an 
akene in fruit. The’ 
corolla being on the 
ovary, the latter is of 
course covered by the 
tube of the calyx adherent to it. Sometimes there is no limb or border to the calyx; 
then the akene is naked, as in that of Mayweed (Fig. 406). When the limb of the calyx 
is present in any form on the ovary or akene, it is named the pappus (which means seed- 
down). In Cichory the pappus or calyx is a ring or cup crowning the akene (Fig. 407) ; 
in Sunflower it consists of two chaffy scales, which fall off early (Fig. 408); in Helenium 
402, Flowers of Cichory, all with strap-shaped corollas. 
403. Head of Cichory-flowers, divided lengthwise and enlarged. 
