An elaiophore (from Gr. ''elaion'' -oil and ''phorein'' -carry) is a plant organ that secretes oil. A distinction is made in: * epithelial elaiophors: oil glands * trichome eaiophores: glandular hairs. The oils consist of fatty acids and/or glycerides, but may also contain other components such as

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

carbohydrate A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ...

carotenoid Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, cana ...

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...

ketone In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone ( ...

s, phenolic compounds,

saponin Saponins (Latin ''sapon'', 'soap' + ''-in'', 'one of') are bitter-tasting, usually toxic plant-derived secondary metabolites. They are organic chemicals that become foamy when agitated in water and have high molecular weight. They are present ...

s and

terpene Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n ≥ 2. Terpenes are major biosynthetic building blocks. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predomi ...

s. Elaiophores occur in the flowers of some families, such as Malpighiaceae, Scrophulariaceae,

Iridaceae Iridaceae () is a family of plants in order Asparagales, taking its name from the Iris (plant), irises. It has a nearly global distribution, with 69 accepted genera with a total of about 2500 species. It includes a number of economically importan ...

Cucurbitaceae The Cucurbitaceae (), also called cucurbits or the gourd family, are a plant family (biology), family consisting of about 965 species in 101 genera.

Primulaceae The Primulaceae ( ), commonly known as the primrose family (but not related to the Onagraceae, evening primrose family), are a family (biology), family of Herbaceous plant, herbaceous and woody flowering plants including some favourite garden pla ...

and

Solanaceae Solanaceae (), commonly known as the nightshades, is a family of flowering plants in the order Solanales. It contains approximately 2,700 species, several of which are used as agricultural crops, medicinal plants, and ornamental plants. Many me ...

. Elaiophores can be present on the axial part of the sepals or corollas, on the surface of the

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

, at the base of

stamens The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

(as in '' Lysimachia vulgaris'') and also on the

callus A callus (: calluses) is an area of thickened and sometimes hardened skin that forms as a response to repeated friction, pressure, or other irritation. Since repeated contact is required, calluses are most often found on the feet and hands, b ...

. The oils secreted by the elaiophores act as attractants for pollinating insects. Representatives of several bee families collect these oils to add to the food of the larvae or to line the nest, including the families and subfamilies

Melittidae Melittidae is a small bee family, with over 200 described species in three subfamilies. The family has a limited distribution, with all described species restricted to Africa and the northern temperate zone. Fossil melittids have been found oc ...

Ctenoplectrini The bee tribe Ctenoplectrini of the subfamily Apinae, with the two genera ''Ctenoplectra'' and ''Ctenoplectrina'', comprises 9 species in tropical Africa, 10 in Asia, and 1 in Australia. Description The Ctenoplectrini are characterised by sho ...

Apidae Apidae is the largest family within the superfamily Apoidea, containing at least 5700 species of bees. The family includes some of the most commonly seen bees, including bumblebees and honey bees, but also includes stingless bees (also used for ...

and Anthophorini. Bees of the subfamily

have specialized oil-collecting structures such as pads or combs on the ventral thorax or on the front and middle legs. Bees visiting flowers with trichome elaiophores generally have pads, and bees visiting flowers with epithelial elaiophores have brush-like combs.

References

Sources

* Gerhard Wagenitz: ''Wörterbuch der Botanik. Morphologie, Anatomie, Taxonomie, Evolution.'' 2., erweiterte Auflage. Nikol, Hamburg 2008, . * Vogel, S. 1969. Flowers offering fatty oil instead of nectar. XI Proc. Intl. Bot. Congress, Seattle, p. 229. Abstr. * Stephen L. Buchmann. 1987
The Ecology of Oil Flowers and their Bees
Annual Review of Ecology and Systematics, Vol. 18 pp. 343-369 * * {{cite journal , last1=Possobom , first1=Clivia Carolina Fiorilo , last2=Machado , first2=Silvia Rodrigues , title=Elaiophores: their taxonomic distribution, morphology and functions , journal=Acta Botanica Brasilica , publisher=FapUNIFESP (SciELO) , volume=31 , issue=3 , date=2017-05-15 , issn=1677-941X , doi=10.1590/0102-33062017abb0088 , pages=503–524, bibcode=2017AcBBr..31..503P , hdl=1843/47821 , hdl-access=free * Pacek-Bieniek A., Budowa i aktywność elajoforów w kwiatach wybranych gatunków z rodziny storczykowatych (Orchidaceae), Uniwersytet Przyrodniczy w Lublinie, 2011. Plant morphology