BOTANY WITH BASICS OF HYDROBOTANY (AQUATIC PLANTS OF UKRAINE) - B.Ye. Yakubenko - 2011

VIII. FUNDAMENTALS OF PLANT MORPHOLOGY AND ANATOMY

Features of Reproduction in Angiosperms

Pollination in Flowering Plants

Types of Pollination

Pollination is The process of pollen transfer from an anther to the stigma of a flower's pistil. Two MAIN TYPES OF pollination are distinguished: self-pollination and cross-pollination (xenogamy).

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Fig. 85. Structure of an orthotropous bitegmic crassinucellate ovule: 1 — micropyle, 2 — integuments, 3 — nucellus, 4 — embryo sac, 5 — chalaza, 6 — egg Cell, 7 — synergids, 8 — secondary Nucleus, 9 — central cell, 10 — antipodals

If pollen is transferred within the same flower or the same plant during the pollination process, this type of pollination is called self-pollination. Three modes of self-pollination are distinguished: autogamy, geitonogamy, and cleistogamy. In autogamy, pollination occurs within a single flower. In geitonogamy, or neighbor pollination, the stigma of a flower is pollinated by pollen from other flowers of the same plant. Cleistogamy occurs in plants with non-opening (so-called cleistogamous) flowers; that is, self-pollination takes place within closed flowers that do not open during anthesis (e.g., violets).

Pollination in which pollen is transferred from a flower of one plant to a flower of another is called cross-pollination (xenogamy). The majority of angiosperms are pollinated in this manner.