. Botany for agricultural students . Botany. 26 FLOWERS of hair-like structures called pappus, as shown in Figure 2J^. 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.
. Botany for agricultural students . Botany. 26 FLOWERS of hair-like structures called pappus, as shown in Figure 2J^. 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 Ladj^'s-slipper, one of the petals is developed into a great sac or " slipper," while the others have no extraordinary features. These ous flowers of" the"TiTdia"!! peculiarities in flower structure, which Turnip {Arisoema iriphyllum). are apparently adjustments for insect pollination, sometimes so closely con- form to the shape and habit of cer- tain insects that only one or a few kinds of insects can pollinate a flower. 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,. 26. — The inconspicu- The flowers shown arc pist
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
