Entomophily - Cross-pollination
It involves insects to carry the pollen to achieve pollination. Salvia exhibits a specialised 'tumapipe' floral mechanism that signifies classic adaptation for bee pollination. In Salvia the corolla is bilipped and the stamens are attached to corolla tube. Only one-half of each anther is fertile, the other half being sterile joins together to form a sterile plate of tissue placed above the lower lip at the mouth of the flower. However, the fertile part lies under the hood of the upper lip of the corolla.
When a bee visits the flower for nectar it pushes against the sterile plate which consequently brings down the fertile anthers on its back dusting it with pollen. When the bee visits another flower, the forked stigmas picks up the pollen from the back of the insect. Plants that are pollinated by insects often have predominantly yellow or blue petals. Among insects bees and butterflies do not perceive color in the same manner as the humans. They are able to see in the ultraviolet range of the electromagnetic spectrum, an area that is invisible to human eye. They see blue and yellow flowers differently than humans. Red emerges out black to them. Consequently, flowers that are pollinated by insects are not usually red. Many insect-pollinated flowers have dramatic ultra-violet markings, that are invisible to us but direct the insect to the flower, where pollen or nectar may be located. Insects comprise a well developed sense of smell.