Dispersal by Wind (Anemochory)

Anemochory is dispersal of seeds or fruits by wind, and it is especially common among tall trees, whose height gives released seeds a longer fall and more time for wind to carry them sideways. Wind-dispersed seeds/fruits show a small set of recurring physical adaptations. Some produce minute seeds — extremely small, light, and often enclosed in an inflated covering that further reduces effective weight (e.g. orchid seeds, which are famously dust-like). Others develop wings — the seed or the whole fruit is flattened out into a wing-like extension that increases air resistance and lets it glide or spin away from the parent tree rather than simply drop straight down (e.g. Maple, Gyrocarpus, Dipterocarpus, Terminalia — the two-winged fruit of Gyrocarpus, in particular, spins like a helicopter blade as it falls). Still others grow feathery appendages — fine hair-like extensions (a coma) attached to the seed that dramatically increase its air resistance/buoyancy and let wind carry it to unusually high altitudes and long distances (e.g. Vernonia, Asclepias). A more specialised wind-dependent trick is the censor mechanism, seen in plants like Aristolochia and p …