
34, | ELEMENTARY BOTANY 
CHAPTER VI 
| THE FLOWER 
Amuee Ir the flower of a buttercup is examined, it will be 
a Modified scen to consist of four sets of leaves, arranged on 
Shoot. 4 central stem ; ; this stem is the apex of the flower 
stalk, and is called the receptacle. The leaf, in the axil of 
which the flower stalk 
is situated, is a bract ; 
t is not always pre- 
ent. A flower is thus 
modified shoot, differ- 
ng from the ordinary 
oliage shoot already 
described as having : 

1. Very short inter- 
nodes. 
2. No buds in the axils. 
Fic. 34.—VERvIcAL SEcTION or BUTTERCUP.. 3. Leaves _ frequently 
rc, receptacle ; s, sepals; p, petals; a, whorled and specially 
stamens ; ¢c, carpels. modified for the produc- 
tion of seed. 
Floral The outermost leaves of the flower are called 
Leaves. senals, and together form the calyx or cup, in 
which the rest:of the flower is, as it were, contained. This is 
best seen in the bud where, as in poppy, the calyx forms a 
complete covering for the other floral leaves and, as soon as 
the flower opens, drops off. 
The next leaves are the petals, forming the corolla. The 
calyx and corolla are not essential for the development ot 
fruit and seed, and are often absent, especially in the flowers 
ot trees. 
The essential leaves of a flower are: (1) the stamens, the 
third whorl of leaves, and (2) the carpels, the innermost leaves. 
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