FIG. 30.22 Fruits and seed dispersal. (a) The seeds of the milkweed Asclepias syriaca are dispersed by wind; (b) a robin is eating berries of mountain ash (Sorbus americana); (c) cocklebur (Xanthium strumarium) fruits are hitching a ride on the fur of a cow; (d) a squirrel carries a fruit it will bury for later use.