. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 3°4 FLOWERS. Fig. 126. — Pollination by means of water as illustrated by the have different parents. plant. This is called geitonog- amy. It is the commonest kind of pollination accomplished by insects. The principal pollinat- ing insects usually explore thoroughly all the flowers of one plant before going to another. (2) The pollen may cross to the stigmas of flowers of other plants of the same kind. This is called xenogamy. Evidently this is a more compl
. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 3°4 FLOWERS. Fig. 126. — Pollination by means of water as illustrated by the have different parents. plant. This is called geitonog- amy. It is the commonest kind of pollination accomplished by insects. The principal pollinat- ing insects usually explore thoroughly all the flowers of one plant before going to another. (2) The pollen may cross to the stigmas of flowers of other plants of the same kind. This is called xenogamy. Evidently this is a more complete kind of crossing than geitonogamy is; in fact, the latter is more closely allied to close-pollination than it is to xenogamy. Close-pollination and geitonogamy both mean that the pollen parent and the ovule parent of the seed are the same, while in xenogamy the pollen and the ovules It is evi- tape grass (Vallisneria). This plant is dioecious. The individ- ual at the left bears a spike of staminate buds (A). These spherical buds (a) become de- tached and rise to the surface, where, as they float, they open and expose the stamens. The pistillate flowers are borne on long stems which come just to the surface of the water. Polli- nation is accomplished by those staminate Jlowers which float against the pistillate ones. After pollination the stem of the pistillate flowers coils into a spiral, withdrawing the ovary below the surface. The fruit develops under the water. dent that all diclinous flowers are cross-pollinated, also that all diclinous flowers borne by dioe- cious plants (see page 284) must be xenogamic. That is, since the staminate and pistillate flowers of diclinous plants are borne on different individuals,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Coulter, John G. (John Gaylord), b. 18
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