Many seeds benefit not only from the dispersal, but the trip through the intestine as well. Digestive acids scarify seeds, helping them to break out of thick seed coats. Some seeds are armed with hooks and barbs that enable them to lodge in the fur of animals that brush past them. Beggar's ticks and bur marigold are two examples. Eventually, the seeds are rubbed or scratched off, and may find a suitable spot on which to germinate and grow.
People are important for dispersing plants, too.
Mutualism Mutualism is an obligate interaction between organisms that requires contributions from both organisms and in which both benefit. There are many examples in nature. Pollination and dispersal, discussed above, are mutualistic because both plant and pollinator or disperser benefit from the relationship. The relationship between mycorrhizal fungi and many higher plants is another common example of mutualism. The bodies of the fungi, called hyphae , live on or in the tissues of plants, and make nutrients available for the plants to absorb.