How do hairs, spines, and barbs help grass seeds disperse?

In the Poaceae family, hairs, spines, and barbs serve as specialized adaptations that facilitate seed dispersal through two primary mechanisms:

• Epizoochory (Animal Attachment): Awns (bristlelike projections), hairs, spines, and barbs located on the spikelets or their parts allow grass seeds to catch onto the fur of passing animals. For example, the spikelets of Cenchrus (sandburs) are equipped with barbed spines that cling to animal fur or attach to the feet of humans, enabling the seeds to be transported to new locations.1
• Wind Dispersal: In addition to their role in animal attachment, hairs can function like parachutes. By increasing surface area and retarding the fall of the seed, these structures help keep the seeds aloft longer, thereby increasing the distance they can travel via wind currents.1

These adaptations are essential for the successful colonization and establishment of grasses in various environments.1