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Why do dandelion flowers have five small teeth at the end of each ligule?

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Sunflower — Asteraceae The flowering head of a sunflower (*Helianthus annuus*) is formed of yellow, petal-like ray flowers and a brown center of minute disk flowers.

The presence of five small teeth at the end of a dandelion's ligule is not a random feature; rather, these teeth represent the tips of the five individual lobes of the corolla that have fused together.1

In the Asteraceae family, members of the tribe Lactuceae—which includes the dandelion—possess ligulate flowers. Unlike the ray flowers found in other types of flower heads, the ligule of a dandelion flower is formed by all five lobes of the corolla. Consequently, the five terminal teeth are the visible remnants of these five distinct petal tips.1