Elaiosomes (
Greek élaion "oil" and
sóma "body") are fleshy structures that are attached to the
seeds of many
plant species. The elaiosome is rich in
lipids and
proteins, and may be variously shaped. Many plants have elaiosomes that attract
ants, which take the seed to their nest and feed the elaiosome to their
larvae. After the larvae have consumed the elaiosome, the ants take the seed to their waste disposal area, which is rich in nutrients from the ant
frass and dead bodies, where the seeds
germinate. This type of seed dispersal is termed
myrmecochory from the Greek "ant" (myrmex) and "dispersal" (kore). This type of
symbiotic relationship appears to be
mutualistic, more specifically dispersive mutualism according to Ricklefs, R.E. (2001), as the plant benefits because its seeds are dispersed to favorable germination sites, and also because it is planted (carried underground) by the ants.