FORM AND STRUCTURE 
THE INDIVIDUAL FLOWER. 
A complete flower consists of four sets of organs which 
botanists regard as modified leaves. These are Calyx, Co- 
rolla, Andrecium the Stamens, and Gynecium the pistils. 
They are borne on a short axis called the receptacle, 
(Fig. 35-) 
The Calyx is the outer set. This is usually green though 
sometimes it is colored. It may consist of a number of 
separate parts called 
Sepals; these may be 
more or less united, 
The Corolla is the 
second set. This is 
usually colored. It may 
consist of a number of 
separate parts called 
petals; these may be 
more or less united. 
The calyx and corolla 
are called the floral 
envelopes because they 
surround and_ protect 
the stamens and pistils, 
which are the essential 
organs of the flower. 
They are called essen- 
tial organs because to- 
gether they produce 
Fic. 35. Cherry Blossom, Showing Calyx (bud), Hie seed. 
Corolla, ‘Stamens, and. Pistil, The Stamens consti- 
tute the third set. A 
stamen consists of two parts, the filament and the anther, 
The Filament is the anther stem. The Anther is the essen- 
tial part and contains the Pollen which it discharges when 
mature. When the filament is wanting the anther is said to 
be sessile. 
The Pistils are at the centre of the flower. It is not often 
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