60 NEW ZEALAND NATURE-STUDY BOOK 
We see then that the blossom of a wall-flower consists of 
a calyx of sepals, a corolla of petals, a whorl of stamens, 
and a pistil containing ovules. 
THE PEA BLOSSOM. 
Structure of Flower. The-Pea blossom is made up 
of a calyx of five united sepals; a curiously-shaped 
corolla, consisting of a large upper petal called the 
standard, two. side petals known as the wing's, and 
two lower petals joined together and forming the keel; 
‘ten stamens, of which nine have their filaments united 
Fig. 49.—A, Pea blossom. B, Parts of blossom. 
st, standard; w, wings; k, keel. 
C, Pea Blossom with Calyx and Corolla removed, shewing the nine united 
Filaments, the tenth one being free. 
to form a tube surrounding the ovary, the tenth being 
free ; and a pistil forming the ovary in which the seeds are 
ripened. 
- The great similarity between the three types of flowers 
we haye examined will gradually become clear. Each 
possesses a calyx of sepals, a corolla of petals, and 
a number of stamens with filaments and anther lobes. 
In the case of the Pea and the Wall-flower, the central 
portion of each consists of a single pistil containing the 
ovary. In the ‘Buttercup the carpels which occupy the 
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