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How do seed coats develop wings, prickles, or hairs that aid seed dispersal?

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A pangolin walks through grass with a blue circle around it and the word endangered written in white across the image. — Integument The pangolin is the only mammal in the world covered in scales.

In the context of plant biology, the seed coat, or testa, is derived from the protective integuments of the ovule. As the ovule matures into a seed, these integuments undergo structural changes, including the thickening of cell walls, to form a protective layer.123

Beyond providing protection and regulating dormancy, the seed coat can develop various morphological adaptations that facilitate seed dispersal by wind or animals. These modifications include:24

Wings: Certain seed coats are flattened or extended into wing-like structures, which increase surface area and allow the seed to be more easily transported by wind.25
Hairs and Plumes: Seeds may be covered in woolly hairs or possess plumed structures, which make them lightweight and buoyant, enabling them to be carried over distances by air currents.5
Prickles and Barbs: Some seed coats are ornamented with prickles or sclerified hairs that allow them to adhere to the fur, skin, or feathers of passing animals, facilitating passive dispersal.245

These specialized features are part of the diverse evolutionary strategies plants use to ensure their offspring are distributed away from the parent plant.45