Seed dispersal by ants.
Etymology: Greek, myrmeco, ants + khoreo, spread, dispersal
elaiosome (ɪˈleɪəˌsəʊm), noun
An oil-rich fleshy structure attached to the seeds of some plants.
Etymology: Greek, elaion, oil + soma, body
The oil-rich elaiosomes are attractive to ants, which then carry the seeds back to their colony. Ant larvae eat the elaiosomes, and the undamaged seeds are discarded.
It's estimated that 5% of all flowering plant species use ants to help disperse seeds, including trillium, bloodroot, violet, bleeding heart, twinleaf, wild ginger, and lamium (dead nettle). In North America, the method is used by many spring-flowering woodland wildflowers. A patient person, situated next to the right plant (or with a cache of the right seeds), can watch the ants in action.