CHAPTER IX 
FLOWERS 
114. The organs of the flower. Although a brief discussion 
of the parts of the flower was presented in Chapter II, it will 
be necessary here to consider them more carefully. Many of 
the most highly organized flowering plants have flowers with 
four sets of organs, as shown in figure 101. The outer set 
(the calyx) consists of parts 
called sepals, which are usually 
green and rather leaf-like. Just 
within or above the calyx comes 
the corolla, which consists of 
leaf-like parts (petals) usually 
of some other color than green. 
Next comes a set of SOMERS, Fie. 101. Flower of Hydrophyllum, 
which very commonly appear side view and lengthwise section 
as stalked organs, each with 4 good example of a flower in which 
an enlarged, knob-like tip. Fi- the parts of each set except the stamens 
A appear to be more or less joined together. 
nally. the innermost, or upper- Modified after Decaisne - 
most, set of organs consists 
of carpels, which, if united, constitute the compound stil, 
or, if separate from one another, constitute the simple pistils. 
Not many flowers have organs as distinct — that is, as 
wholly separate from each other—as they are in the live- 
forever (fig. 102). In the Hydrophyliin (fig. 101) the organs 
of each set, except the stamens, appear to be more or less 
united. The pistil seems to be all of one piece, except that 
it is two-forked at the tip. Hardly any two kinds of flowers 
have exactly the same forms and arrangements of the floral 
organs. A few of the forms are figured in Chapter NX. 
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