2.3 Plant Adaptions For Pollination Flashcards
Wind Pollination
eg. Zea mays
Small perianth.
Abundant, dry/dusty, non sticky pollen > easily carried in air currents.
Large exserted stigma- hanging out if flower.
Stigma has large surface area, can be feathery.
No nectar.
Generally lacking colour.
Bee Pollination
eg Digitalis purpurea
Often, blue, yellow or white, less frequently red (not seen by insects).
Nectarines produce sweet scent to attract pollinators.
Floral tubes of varying lengths which can be reached by proboscis.
Pollen rubs off into bee as it forages - this is deposited into the sticky stigma of next flower which is visited.
Moth pollination
Eg Matthiola longipetala
Open at night, when moths are often flying.
White or pale colored, visible at night.
Strong scent to attract pollinators, often noticeable late evening.
Nectar reward.
Fly pollination
Mimics rotting flesh.
Many flies use rotting flesh to lay eggs in.
Plants mimic odor and appearance/colour of carrion.
Odor can carry many hundreds of meters.
eg. Amorphophallus titanium
Fly pollination (nectar or pollen-feeding)
Achillea app.
Some flies are nectar or pollen-feeding eg. hoverflies.
These flies are dusted with pollen at departure.
Lack scent.
Open flowers, bright clouds, blue, white or purple.
Compound umbels to provide landing area.
Butterfly Pollination
Buddleja davidii
Brightly colored flowers.
Pink, lilac, orange or red.
Reward of nectar.
Often scented.
Flowers often arranged in clusters.
Butterflies rest at feeding and probe individual flowers with long proboscis.
Butterflies are not as efficient as other insects as they are raised in long legs above flower. Less likely to become covered in pollen.
Bird pollination.
Eg.Hibiscus Nectar, but no nectar guides. Vivid colors particularly red. Regular flower shape. Downward pointing corolla. No landing stage, birds hover. Pollen deposits on head as bird bribes the flower with long, specialist tongue. Follows guide beak. Flowers during the day.
Mimicry in pollination
Eg. Ophrys insecifera
Mimics female wasp.
Male wasp tries to mate with it > pollination is achieved.
Flower scent resembles a sexually mature female wasp.
Hairy labium of flower makes male wasp orientate itself correctly.
Flowering synchronizes with male wasps’ emergence from hibernation.
Self compatibility
Favours cross-pollination
Genetic mechanism
Prevents fertilization between flowers on the same plant.
Pollen landing in genetically identical stigma fails to germinate or pollen tube growth is very slow eg. brassicaceae.
Heterostyly
Structural mechanism to favour cross- pollination
Eg. primula
Flowers have stigma and stamens of varying lengths.
Thrumb eyed flower-anthers emerge farther from base, insects rub against them reaching into flowers.
Pin eyed flowers - stigma protrudes from flower, will catch pollen from the same place on insect body.
Flowers in a plant are either all thumb eyed or pin eyed.
Separation of sexes in time - description and definition of protandry and protogyny.
Male and female organs of the flower mature at different times, this ensures that the flower a not self pollinate. (Sequential hermaphroditism)
Protoandry -Pollen matures and is shed before stigma become receptive.
Protogyny -Stigma is receptive before pollen is mature and shed.
Restriction of self-pollination - flowering time
Plants in a species may flower at different times making it impossible for them to self pollinate eg. Malus domestica
Dioecy
Production of distinct male and female flowers allowing plant to reduce likelihood of self pollination
Monoecious
Male and female flowers are in the same plant eg. Malva Sylvestris
Dioecious
Maile and female flowers found on different plants. Male flowers and female plants, without both no berries are produced eg. Ilex aquifolium or Skimmia japonica
