Elaiosomes ( grc, ἔλαιον ''élaion'' "oil" + ''sóma'' "body") are fleshy structures that are attached to the

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

s of many

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae excl ...

species. The elaiosome is rich in

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids in ...

s and

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

s, and may be variously shaped. Many plants have elaiosomes that attract

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

s, which take the seed to their nest and feed the elaiosome to their

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e. 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 Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter. Definition and etymology ''Frass'' is an informal term and accordingly it is variously used and variously defined. It is derived from the ...

and dead bodies, where the seeds

germinate Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...

. This type of seed dispersal is termed

myrmecochory Myrmecochory ( (sometimes myrmechory); from grc, μύρμηξ, mýrmēks ("ant") and ''khoreíā'' ("circular dance") is seed dispersal by ants, an ecologically significant ant–plant interaction with worldwide distribution. Most myrmec ...

from the Greek "ant" (myrmex) and "circular dance" (khoreíā). This type of

symbiotic Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or para ...

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. Elaiosomes develop in various ways either from seed tissues (chalaza, funiculus, hilum, raphe-antiraphe) or from fruit tissues (exocarp, receptacle, flower tube, perigonium, style or spicule). The various origins and developmental pathways apparently all serve the same main function, i.e. attracting ants. Because elaiosomes are present in at least 11,000, but possibly up to 23,000 species of plants, elaiosomes are a dramatic example of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

in flowering plants.

Caruncle

The particular elaiosome in the spurge family ''

Euphorbiaceae Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as '' Euphorbia paralias'', are herbs, but some, ...

'' is called caruncle (

Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

''caruncula'' "wart"). Seeds that have a caruncle are ''carunculate'', seed that do not have a caruncle are ''ecarunculate''.

List

A fully referenced current list of plants that have seeds with elaiosomes can be found in Lengyel ''et al.'' (2010). *''

Chelidonium majus ''Chelidonium majus'', the greater celandine, is a perennial herbaceous flowering plant in the poppy family Papaveraceae. One of two species in the genus ''Chelidonium'', it is native to Europe and western Asia and introduced widely in North Ame ...

'' (greater celandine) *''

Claytonia virginica ''Claytonia virginica'', the Virginia springbeauty, eastern spring beauty, grass-flower or fairy spud, is an herbaceous perennial plant in the family Montiaceae. Its native range is eastern North America. Its scientific name honors Colonial Vir ...

'' *'' Cnidoscolus urens'' *''

Corydalis ''Corydalis'' (from Greek ''korydalís'' " crested lark") is a genus of about 470 species of annual and perennial herbaceous plants in the family Papaveraceae, native to the temperate Northern Hemisphere and the high mountains of tropical e ...

'' *''

Dicentra ''Dicentra'' ( Greek ''dís'' "twice", ''kéntron'' "spur"), known as bleeding-hearts, is a genus of eight species of herbaceous plants with oddly shaped flowers and finely divided leaves, native to eastern Asia and North America. Description F ...

'' (bleeding-heart, Dutchman's breeches) *'' Hyacinthus'' (hyacinth) *''

Myrtus ''Myrtus'' (commonly called myrtle) is a genus of flowering plants in the family Myrtaceae. It was first described by Swedish botanist Linnaeus in 1753. Over 600 names have been proposed in the genus, but nearly all have either been moved ...

'' (myrtle) *'' Ricinus communis'' (castor oil plant) *''

Sanguinaria canadensis ''Sanguinaria canadensis'', bloodroot, is a perennial, herbaceous flowering plant native to eastern North America. It is the only species in the genus ''Sanguinaria'', included in the poppy family Papaveraceae, and is most closely related to ...

'' (Bloodroot) *''

Trillium ''Trillium'' (trillium, wakerobin, toadshade, tri flower, birthroot, birthwort, and sometimes "wood lily") is a genus of about fifty flowering plant species in the family Melanthiaceae. ''Trillium'' species are native to temperate regions of No ...

'' *''

Viola ; german: Bratsche , alt=Viola shown from the front and the side , image=Bratsche.jpg , caption= , background=string , hornbostel_sachs=321.322-71 , hornbostel_sachs_desc=Composite chordophone sounded by a bow , range= , related= *Violin family ...

'' (violet)

References

{{reflist, 1

External links

*http://waynesword.palomar.edu/plaug99.htm#antdispersal Fruit morphology Insect ecology

Caruncle

List

See also

References

External links