26 FLOWERS 
of hair-like structures called pappus, as shown in Figure 24. In 
some, as the Dandelion illustrates, the pappus remains after the 
seed is mature, forming a parachute-like arrangement which 
assists in floating the seed about. In some of the Composites, 
the calyx consists of a few teeth, which in the Spanish Needles 
and Beggar’s Tick, become spiny, and 
thereby assist in seed distribution by 
catching onto passing objects. 
Orchid Flowers. — It is among 
Orchid flowers, many of which are 
spectacular, that the most notable 
irregularities occur. Besides the dis- 
tinguishing feature of having the 
stamens and pistil joined into one 
body, known as the column, Orchid 
flowers often have pronounced varia- 
tions in the shape and size of petals. 
In some, as in the Lady’s-slipper, one 
of the petals is developed into a great 
sac or “‘slipper,’’ while the others 
have no extraordinary features. These 
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Fic. 26.— The inconspicu- Satna ine ; 
ous flowers of the Indian PeCuliarities in flower structure, which 
Turnip (Arisema triphyllum). are apparently adjustments for insect 
The flowers shown are pistil- pollination, sometimes so closely con- 
late and are clustered at the z 
bie: ob the Hehe ane ae form to the shape and habit of cer- 
spadix which is enclosed in the tain insects that only one or a few 
large leaf-like bract or spathe. kinds of insects can pollinate a flower. 
Reduced about one-half. Such highly modified flowers contrast 
strikingly with the simple, inconspicuous flowers of such plants 
as the Jack-in-the-pulpit or Indian Turnip and Skunk Cabbage, 
in which a perianth is either lacking or inconspicuous and the 
flowers are crowded on a fleshy spike, known as a spadix, which 
is enclosed in or attended by a leaf, called spathe. The spathe, 
by becoming colored, often aids like a corolla in attracting 
insects. (Figs. 25 and 26.) 
Arrangement of Flowers or Inflorescence 
The arrangement of flowers on the stem is one of the floral 
characters much used in the classification of the Flowering Plants. 
In the arrangement of flowers, a number of things are considered, 
