Anemochory - Dispersal of Seeds
Seeds that are dispersed by air currents are usually light or are provided with special structures to help them remain air-borne for long periods. Since a large proportion of seeds are wasted, anemochorous plants usually produce a profuse quantity of seeds per plant.
Figure: A seed of cypripedium. Embryo can be seen without endosperm through transparent seed-coat.
Some of the orchids, for example, produce as much as seven hundred million seeds per plant and the seeds are so tiny that these are blown away like dust particles. The orchid seeds have an undifferentiated embryo and lack endosperm.