pappus

Pappus refers primarily to a botanical structure found on the fruits of many flowering plants, especially in the Asteraceae family. It is formed from modified sepals of the flower and persists after fertilization as a tuft of hairs, bristles, or scales attached to the seed. The pappus can take a range of forms—from soft, plumed hairs to a ring or cluster of scales—depending on the species.

The main function of the pappus is to aid seed dispersal by wind (anemochory). Its lightweight, extended form can catch air and slow the descent of the seed, allowing it to travel farther from the parent plant. This adaptation is well known in the common dandelion (Taraxacum) and numerous thistles, among others. Some species either lack a pappus or possess a reduced structure, reflecting diverse dispersal strategies.

Etymology and related terms: The word pappus comes from Latin, meaning a tuft or cotton-like structure. In a separate field, the term appears in geometry as Pappus’s centroid theorem, attributed to Pappus of Alexandria, which relates the volume and surface area of solids of revolution to the centroid of a generating curve. Although sharing the name, this mathematical usage is unrelated to the botanical pappus.

In summary, the botanical pappus is a calyx-derived tuft that enhances wind-mediated seed dispersal, with notable variation across plant groups.