Elaiosomes (elaios- oil, some- 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 to 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, as the plant benefits because its seeds are dispersed to favorable germination sites, and also because it is planted (carried underground) by the ants. Elaiosomes are an example of convergent evolution, having evolved many times in thousands of different plant species. Elaioplasts is another name for fat-producing cells (plastids). Actually many of the spring flowering plants such as Narcissus or Hyacinthus have such structure.
Some examples of plants that have elaiosomes are:
The particular elaiosome in plant family Euphorbiaceae is called caruncle (lat. caruncula: wart). Seeds that have a caruncle are carunculate, seed that do not have a caruncle are ecarunculate.
 Afzelia africana seed bearing elaiosomes |
 Trillium recurvatum seeds with elaiosomes |
 Carunculate seed of Ricinus communis (Castor beans) |
 Carunculate seed of Euphorbia mafingensis |
See also
- Aril
- Capitulum, a similar appendage with similar purposes found in stick insect eggs.
- Myrmecochory
External links
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