Bright colors - may be specific for the type of insect. Large,
conspicuous petals and/or sepals The flowers produce scent to
attract the insects. Nectar may be produced as a food reward.
Nectar is high in sugars and is produced at the base of the flower
to increase the chances of the insect moving against the anthers
and stigma. Some insects, such as beetles, feed on the petals.
Many are bisexual flowers - each visit by the insect is more
efficient because the insect can both pick up and deliver pollen.
Varieties of floral shape and size. Some orchids have elaborate
shapes that mimic female insects.
Pollen grains may be packed with starch or oils and thus are an
important source of food. Less pollen is produced. The exine of the
pollen is contoured and shaped to help it cling to the insect. The
structure of the exine is specific for the various plant groups and
is used as a diagnostic feature.
The stigma is within the perianth - the insect is forced to move
against stigma when moving inside the perianth. Simple or compound
carpels are present.