🌼 Types of Pollination
Type Definition
Autogamy Pollen transfer within the same flower
Geitonogamy Transfer to another flower on the same plant
Xenogamy Transfer to a flower of a different plant
🧠 Trick to remember: “Auto = Same flower, Geito = Same plant, Xeno = Different plant”
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🌬️ Agents of Pollination
🔹 Abiotic Agents
Agent Adaptation
Wind (Anemophily) Small, dry pollen, feathery stigma (e.g., maize)
Water (Hydrophily) Light pollen, floating stigmas (e.g., Vallisneria)
🔸 Biotic Agents
Agent Example Adaptations
Insects Sunflower, Salvia Bright petals, nectar
Birds Hibiscus Tubular flowers
Bats Bauhinia Night blooming
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🌺 Features of Insect-Pollinated Flowers (Entomophily)
Brightly colored petals
Sweet fragrance
Nectar glands
Sticky pollen
🧠 Mnemonic: “Bright, Fragrant, Sticky, Sweet = Bug Treat”
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🌱 Outbreeding Devices in Plants
To prevent self-pollination and promote genetic diversity:
Dichogamy: Anther and stigma mature at different times
Herkogamy: Physical barrier between anther and stigma
Self-incompatibility: Genetic mechanism prevents fertilization
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🌿 Pollen-Pistil Interaction
Pollen germinates on stigma
Pollen tube grows toward ovule
Double fertilization occurs in angiosperms
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