58 @OASS-BOOK OF BOUANY, 
or capitulum.* Hach head is surrounded by a calyx-like 
involucre of purple-edged bracts. In order still further to 
make the heads conspicuous, the florets of the outer row have 
their corollas specially modified, so as to ditfer not only in 
shape, but also in colour, from those within: these white 
outer florets form the ray, and the yellow inner ones the disc, 
of the flower-head, We must examine each kind in detail, 
Each ray-floret consists of an inferior ovary, a white 
corolla, and a 2-branched style. ‘The calyx appears at first to 
be quite wanting, but its tube is in reality adnate 
to the ovary, while the merest trace of a ring 
above the ovary is all that can be seen of the 
limb. The corolla is all in one piece—i.e., its 
component petals are joined together (=gamo- 
petalous or synpetalous}) — and, beyond 
having a slight notch at the apex, there igs 
nothing to show how many petals it is com- 
posed of. The lowest portion, just above the 
ovary, is in the form of a tube, but the creater 
part of it is spread out into a flat limb, giving 
_— _ it the characteristic strap-like shape from 
fig. 101. Ray- s ‘ A ioe tae fee 
floret of Ox. Which its name ligulatet is derived. Note 
eye Daisy, that its adhesion is epigynous. There are 
no stamens in this flower, but from the 
middle of the top of the ovary arises a single style, dividing 
into two branching arms. The flowers therefore are ? in 
structure. Make a longitudinal section of the ovary, and 
notice that it is l-celled and contains a single erect ovule. 
When the fruit is ripe you will see that it is a terete achene, 
which bears on the top a minute disc or crown, representing 
the calyx-limb. The seed has two plano-conyex cotyledons, 
but no endosperm, | | 
Inside the solitary row of ray-floreis are very many 
(several hundred) % disc-florets crowded together. In these 
also the calyx-limb is quite absent. ~T'he corolla is not irre- 
gular as in the floret of the ray, but is tubular of slightly 
dilated in shape, and has its limb or free portion 4- or 4- 
toothed, showing the number of petals which are combined - 
to form it. On the inside of the corolla-tube (which you must 
split open in order to find them), and attached to its walls by 
their filaments, you will find 5 stamens. This form of adhe- 
sion of stamens is called epipetalous.§ Notice that the sta- 
mens have their long slender anther-cells all joined together 
a me) 
SPO rane sesh oereebaintiveven tre! 
* Lat. capitulum, a little head. 
t Gr. gamos, union ; or sun, together. 
} Lat. ligula, a shoe-strap. 
§ Gr. epi, upon—the petals. 
