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**Petal Structure and Classification:**
– The collection of all petals in a flower is referred to as the corolla.
– Corolla types include apopetalous, polypetalous, choripetalous, gamopetalous, and sympetalous.
– Some plants have a corolla that forms a tube.
– Fused tepals are termed syntepalous.
– Petals can differ dramatically in different species.
– The number of petals in a flower may indicate plant classification.
– Flowers on eudicots frequently have four or five petals, while monocots typically have three or six petals.
– The petal whorl may be radially or bilaterally symmetrical.

**Genetics and Evolution of Petal Formation:**
Petal formation is in accordance with the ABC model of flower development.
– Sepals, petals, stamens, and carpels are modified versions of each other.
Petal formation mechanisms evolved few times rather than repeatedly.

**Significance of Petals in Pollination:**
Pollination is crucial for the sexual reproduction of higher plants.
– Petals play a significant role in attracting pollinators.
– Flowers compete to attract pollinators for pollination.
– Petals aid in prolonging the survival of flower species.

**Functions and Features of Petals in Pollination:**
– Petals protect some parts of the flower and attract/repel specific pollinators.
Flower petals aid pollinators towards the nectar and draw them by providing incentives.
– Petals produce scents, mimic scents, use various colors, and have specific shapes and sizes to attract or repel pollinators.
– Flowers adapt mechanisms on their petals to change color as a signal for birds and bats.

**Specialized Pollination Mechanisms:**
– Wind-pollinated flowers have small, dull petals, and some may have no petals.
– Flowers attract insects using color guiding marks and shapes aiding insect landing and pollination.
– Flowers pollinated by birds must be large and colorful, with adaptations on petals to signal pollination status.
– Bat-pollinated flowers lack color but have nectar and a strong scent to attract bats, like the example of Dactylanthus acting as a parasite on forest tree roots.

Petal (Wikipedia)

Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the corolla. Petals are usually accompanied by another set of modified leaves called sepals, that collectively form the calyx and lie just beneath the corolla. The calyx and the corolla together make up the perianth, the non-reproductive portion of a flower. When the petals and sepals of a flower are difficult to distinguish, they are collectively called tepals. Examples of plants in which the term tepal is appropriate include genera such as Aloe and Tulipa. Conversely, genera such as Rosa and Phaseolus have well-distinguished sepals and petals. When the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly colored tepals. Since they include Liliales, an alternative name is lilioid monocots.

Diagram showing the parts of a mature flower. In this example, the perianth is separated into a calyx (sepals) and corolla (petals)

Although petals are usually the most conspicuous parts of animal-pollinated flowers, wind-pollinated species, such as the grasses, either have very small petals or lack them entirely (apetalous).

Tetrameric flower of a primrose willowherb (Ludwigia octovalvis) showing petals and sepals
A tulip's actinomorphic flower with three petals and three sepals, that collectively present a good example of an undifferentiated perianth. In this case, the word "tepals" is used.
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