ADAPTATIONS RELATED TO INSECT AND WIND
POLLINATION
• Pollination: the transfer of pollen grains from anthers to the stigmas;
• external agents are needed –
• (1) by insect
• (2) by wind
• Comparison of anemophilous (wind-pollinated)
and entomorphilous (insect-pollinated) flowers
wind-pollinated insect-pollinated
Example: grass Example: Bauhinia
Plants often occur in dense groups covering large areas
…in small groups
Flowers occur in groups
(inflorescences) on the plant
…may be solitary or in groups
Flowers often unisexual with an excess of male flowers
Mostly bisexual
wind-pollinated insect-pollinated
Petals are dull and
much reduced in size
…large & brightly coloured, conspicuous to insects
No scent or nectary Scent and/or nectary to attract insect
Stigmas protrude outside flower on long styles
…lie deep inside corolla
Stigmas are feathery, giving them a large surface area to filter pollen from the air
…relatively small because they are easily touched by insects
wind-pollinated insect-pollinated
Anthers hang outside flower on long filaments so the pollens are easily released into the air
…lie inside flower to touch insects when they come to collect nectar
Large number of pollens are produced to offset the high degree of wastage during dispersal
Less pollens because high chance of successful pollination and to reduce wastage
Pollen is smooth, light & small and sometimes have wing-like extensions to aid wind transport
…larger and often have projections to adhere to insects