Elaiosomes

Elaiosomes are fleshy appendages that are found on many sorts of seeds. No one is quite sure why they evolved. Because ants often carry such seeds back to their nests and eat the elaiosomes, leaving the seed apparently unharmed, one suggestion is that they evolved as a ‘reward’ for ants, encouraging them to disperse the seeds. An alternative proposal is that elaiosomes may help the seed to absorb and retain moisture for germination.