. Elementary botany . scales.) The stamens are united by their anthers into a tube (syngenecious) which closely surrounds the style. (In am- brosia the anthers are sometimes distinct.) The style in pushing through brushes out some of the pollen from the anthers and bears it aloft as in the bell-flower, but the stigmatic surface is not yet mature and expanded, so that close pollination cannot take place. There are usually no stamens in the ray-flowers. The ovary is composed of two carpels, as is shown by the two styles, but there is only one locule, containing an erect, anatropous, ovule. The f
. Elementary botany . scales.) The stamens are united by their anthers into a tube (syngenecious) which closely surrounds the style. (In am- brosia the anthers are sometimes distinct.) The style in pushing through brushes out some of the pollen from the anthers and bears it aloft as in the bell-flower, but the stigmatic surface is not yet mature and expanded, so that close pollination cannot take place. There are usually no stamens in the ray-flowers. The ovary is composed of two carpels, as is shown by the two styles, but there is only one locule, containing an erect, anatropous, ovule. The floral formula for the composite family\ then is as follows: Ca5, C05, A5, G2. 555. The rattlesnake-weed (Hieracium veno- sum) is an example of another type, with only _ Flg'3?7' / r ;1 ' J Diagram of composite one kind of flower in the head, the true ligu- flowei:- (vines) late flower. The hawkweed, or devil's paint-brush (H. aurantiacum) is a re- lated species, which is a troublesome weed. The dandelion and prickly lettuce are also members of the ligulate- flowered composites. A number of the composites have only tubular flowers, as in the thoroughwort (eu- patorium) and everlasting (anten- naria). 556. The extent to which the union of the parts of the flower has been carried in the composites, and the close aggregation of the flowers in a head, represent the highest stage of evolution reached by the flowers of the angiosperms. The composites stand just above the bell-flowers and lobelias, at the termination of a series. The teasels show a relationship to the composites in the aggre- gation of the flowers in a head. But the con- solidation of the parts of the flower has not been carried so far, and the flower- arc eacb separated l>v an "epicalyx " in the form of a minute cup- shaped involucre. The teasels stand .it the termination of another series in
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