. The Indiana weed book. Weeds. STAMENS AND THEIR WORK. 37 families some or all of the small tubular corollas appear as if split part way down on one side and then flattened. Such a corolla is said to be ligulate or strap-shaped, the split portion being called a ray. The corolla is often wrongly called the "; This is be- cause it is usually the showy or attractive part to humans. How- ever, it was not made handsome to attract man but insects, so as to bring about a better pollination or cross fertilization of the es- sential organs. It also serves to some extent to protect tho
. The Indiana weed book. Weeds. STAMENS AND THEIR WORK. 37 families some or all of the small tubular corollas appear as if split part way down on one side and then flattened. Such a corolla is said to be ligulate or strap-shaped, the split portion being called a ray. The corolla is often wrongly called the "; This is be- cause it is usually the showy or attractive part to humans. How- ever, it was not made handsome to attract man but insects, so as to bring about a better pollination or cross fertilization of the es- sential organs. It also serves to some extent to protect those or- gans in the bud. In endogens the sepals and petals are, when pres- ent, 3 each in number and often colored alike to form what is known as the perianth, - The duty of the stamens, or outer set of essential organs of a. Fig. 11. Illustrating stamens and pollen grains: a, stamen of henbane, f, filament, p. ; 6, flower of mallow with calyx and corolla cut away, showing the monodelphous stamens unite! in a col imn around the styles; c, stamens of pea in two groups idiadelphous) 9 and 1; d. stamen with versatile anther as in grasses and evening- primrose; e, stamen of horse nettle, the pollen escaping by terminal pores; /, stamens of a Composite showing the anthers united in a tube: g, same with tube split and spread out; A, a 3-lobed pollen grain of evening-prim- rose; i, a pair of pollen masses of a milkweed flower attached by stalks to a gland. (After Gray.) flower when both are present, is to produce pollen grains or spores. These grains are the male or fertilizing agents of the flower. A stamen usually consists of a stalk or filament and an anther, the latter being made up of 2 sacs or cells in which the pollen is formed and held until it is ready for use. When the pollen is ripe the sacs open by slits or pores and the pollen is scattered by the wind, insects or other agencies. The stamens vary greatly in num- ber, length of filament, form of anther, degree of union
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectweeds, bookyear1912
