Nectar

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Nectar of camellia Nectar.jpg
Nectar of camellia
Orange-yellow nectaries and greenish nectar in buckwheat flowers Buckwheat flowers macro.jpg
Orange-yellow nectaries and greenish nectar in buckwheat flowers
An Australian painted lady feeding on a flower's nectar Australian painted lady feeding closeup.jpg
An Australian painted lady feeding on a flower's nectar
Gymnadenia conopsea flowers with nectar-filled spur 0rchideen 04.jpg
Gymnadenia conopsea flowers with nectar-filled spur

Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide herbivore protection. Common nectar-consuming pollinators include mosquitoes, hoverflies, wasps, bees, butterflies and moths, hummingbirds, honeyeaters and bats. Nectar plays a crucial role in the foraging economics and evolution of nectar-eating species; for example, nectar foraging behavior is largely responsible for the divergent evolution of the African honey bee, A. m. scutellata and the western honey bee.[ citation needed ]

Contents

Nectar is an economically important substance as it is the sugar source for honey. It is also useful in agriculture and horticulture because the adult stages of some predatory insects feed on nectar. For example, a number of predacious or parasitoid wasps (e.g., the social wasp species Apoica flavissima ) rely on nectar as a primary food source. In turn, these wasps then hunt agricultural pest insects as food for their young. [1]

Nectar is most often associated with flowering plants angiosperms, but it is also produced by other groups, including ferns. [2]

Etymology

Nectar is derived from Greek νεκταρ, the fabled drink of eternal life. [3] Some derive the word from νε- or νη- "not" plus κτα- or κτεν- "kill", meaning "unkillable", thus "immortal". The common use of the word "nectar" to refer to the "sweet liquid in flowers", is first recorded in AD 1600. [3]

Floral nectaries

A nectary or nectarine is floral tissue found in different locations in the flower and is one of several secretory floral structures, including elaiophores and osmophores, producing nectar, oil and scent respectively. The function of these structures is to attract potential pollinators, which may include insects, including bees and moths, and vertebrates such as hummingbirds and bats. Nectaries can occur on any floral part, but they may also represent a modified part or a novel structure. [4] The different types of floral nectaries include: [5]

Most members of Lamiaceae have a nectariferous disc which surrounds the ovary base and derived from developing ovarian tissue. In most Brassicaceae, the nectary is at the base of the stamen filament. Many monocotyledons have septal nectaries, which are at the unfused margins of the carpels. These exude nectar from small pores on the surface of the gynoecium. Nectaries may also vary in color, number, and symmetry. [6] Nectaries can also be categorized as structural or non-structural. Structural nectaries refer to specific areas of tissue that exude nectar, such as the types of floral nectaries previously listed. Non-structural nectaries secrete nectar infrequently from non-differentiated tissues. [7] The different types of floral nectaries coevolved depending on the pollinator that feeds on the plant's nectar. Nectar is secreted from epidermal cells of the nectaries, which have a dense cytoplasm, by means of trichomes or modified stomata. Adjacent vascular tissue conducts phloem bringing sugars to the secretory region, where it is secreted from the cells through vesicles packaged by the endoplasmic reticulum. [8] The adjacent subepidermal cells may also be secretory. [4] Flowers that have longer nectaries sometimes have a vascular strand in the nectary to assist in transport over a longer distance. [9] [4]

Pollinators feed on the nectar and depending on the location of the nectary the pollinator assists in fertilization and outcrossing of the plant as they brush against the reproductive organs, the stamen and pistil, of the plant and pick up or deposit pollen. [10] Nectar from floral nectaries is sometimes used as a reward to insects, such as ants, that protect the plant from predators. Many floral families have evolved a nectar spur. These spurs are projections of various lengths formed from different tissues, such as the petals or sepals. They allow for pollinators to land on the elongated tissue and more easily reach the nectaries and obtain the nectar reward. [6] Different characteristics of the spur, such as its length or position in the flower, may determine the type of pollinator that visits the flower. [11]

Defense from herbivory is often one of the roles of extrafloral nectaries. Floral nectaries can also be involved in defense. In addition to the sugars found in nectar, certain proteins may also be found in nectar secreted by floral nectaries. In tobacco plants, these proteins have antimicrobial and antifungal properties and can be secreted to defend the gynoecium from certain pathogens. [12]

Floral nectaries have evolved and diverged into the different types of nectaries due to the various pollinators that visit the flowers. In Melastomataceae, different types of floral nectaries have evolved and been lost many times. Flowers that ancestrally produced nectar and had nectaries may have lost their ability to produce nectar due to a lack of nectar consumption by pollinators, such as certain species of bees. Instead they focused on energy allocation to pollen production. Species of angiosperms that have nectaries use the nectar to attract pollinators that consume the nectar, such as birds and butterflies. [13] In Bromeliaceae, septal nectaries (a form of gynoecial nectary) are common in species that are insect or bird pollinated. In species that are wind pollinated, nectaries are often absent because there is no pollinator. [14] In flowers that are generally pollinated by a long-tongued organism such as certain flies, moths, butterflies, and birds, nectaries in the ovaries are common because they are able to reach the nectar reward when pollinating. Sepal and petal nectaries are often more common in species that are pollinated by short-tongued insects that cannot reach so far into the flower. [15]

Secretion

Nectar secretion increases as the flower is visited by pollinators. After pollination, the nectar is frequently reabsorbed into the plant. [16] The amount of nectar in flowers at any given time is variable due to many factors, including flower age, [17] plant location, [18] and habitat management. [19]

Extrafloral nectaries

Extrafloral nectaries of a Wild Cherry.jpg
Extrafloral nectaries with droplets of nectar on the petiole of a wild cherry ( Prunus avium ) leaf
Prunus africana nectaries.jpg
Extrafloral nectaries on a red stinkwood ( Prunus africana ) leaf

Extrafloral nectaries (also known as extranuptial nectaries) are specialised nectar-secreting plant glands that develop outside of flowers and are not involved in pollination, generally on the leaf or petiole (foliar nectaries) and often in relation to the leaf venation. [20] [21] They are highly diverse in form, location, size, and mechanism. They have been described in virtually all above-ground plant parts—including stipules, cotyledons, fruits, and stems, among others. They range from single-celled trichomes to complex cup-like structures that may or may not be vascularized. Like floral nectaries, they consist of groups of glandular trichomes (e.g., Hibiscus spp.) or elongated secretory epidermal cells. The latter are often associated with underlying vascular tissue. They may be associated with specialised pockets (domatia), pits or raised regions (e.g., Euphorbiaceae). The leaves of some tropical eudicots (e.g., Fabaceae) and magnoliids (e.g., Piperaceae) possess pearl glands or bodies which are globular trichomes specialised to attract ants. They secrete matter that is particularly rich in carbohydrates, proteins and lipids. [20] [22]

Ants on extrafloral nectaries in the lower surface of a young Drynaria quercifolia frond Ants on Drynaria.jpg
Ants on extrafloral nectaries in the lower surface of a young Drynaria quercifolia frond

While their function is not always clear, and may be related to regulation of sugars, in most cases they appear to facilitate plant insect relationships. [20] In contrast to floral nectaries, nectar produced outside the flower generally have a defensive function. The nectar attracts predatory insects which will eat both the nectar and any plant-eating insects around, thus functioning as "bodyguards". [23] Foraging predatory insects show a preference for plants with extrafloral nectaries, particularly some species of ants and wasps, which have been observed to defend the plants bearing them. Acacia is one example of a plant whose nectaries attract ants, which protect the plant from other insect herbivores. [20] [21] Among passion flowers, for example, extrafloral nectaries prevent herbivores by attracting ants and deterring two species of butterflies from laying eggs. [24] In many carnivorous plants, extrafloral nectaries are also used to attract insect prey. [25]

Loxura atymnus butterflies and yellow crazy ants consuming nectar secreted from the extrafloral nectaries of a Spathoglottis plicata bud Loxura atymnus-Kadavoor-2018-06-18-001.jpg
Loxura atymnus butterflies and yellow crazy ants consuming nectar secreted from the extrafloral nectaries of a Spathoglottis plicata bud

Charles Darwin understood that extrafloral nectar "though small in quantity, is greedily sought by insects" but believed that "their visits do not in any way benefit the plant". [26] Instead, he believed that extrafloral nectaries were excretory in nature (hydathodes). Their defensive functions were first recognized by the Italian botanist Federico Delpino in his important monograph Funzione mirmecofila nel regno vegetale (1886). Delpino's study was inspired by a disagreement with Darwin, with whom he corresponded regularly. [26]

Extrafloral nectaries have been reported in over 3941 species of vascular plants belonging to 745 genera and 108 families, 99.7% of which belong to flowering plants (angiosperms), comprising 1.0 to 1.8% of all known species. They are most common among eudicots, occurring in 3642 species (of 654 genera and 89 families), particularly among rosids which comprise more than half of the known occurrences. The families showing the most recorded occurrences of extrafloral nectaries are Fabaceae, with 1069 species, Passifloraceae, with 438 species, and Malvaceae, with 301 species. The genera with the most recorded occurrences are Passiflora (322 species, Passifloraceae), Inga (294 species, Fabaceae), and Acacia (204 species, Fabaceae). [22] Other genera with extrafloral nectaries include Salix (Salicaceae), Prunus (Rosaceae) and Gossypium (Malvaceae). [24]

Nylanderia flavipes ant visiting extrafloral nectaries of Senna Nylanderia flavipes extrafloral nectary.jpg
Nylanderia flavipes ant visiting extrafloral nectaries of Senna

Foliar nectaries have also been observed in 101 species of ferns belonging to eleven genera and six families, most of them belonging to Cyatheales (tree ferns) and Polypodiales. [27] [22] They are absent in bryophytes, gymnosperms, early angiosperms, magnoliids, and members of Apiales among the eudicots. [22] Phylogenetic studies and the wide distribution of extrafloral nectaries among vascular plants point to multiple independent evolutionary origins of extrafloral nectaries in at least 457 independent lineages. [22]

Components

The main ingredients in nectar are sugars in varying proportions of sucrose, glucose, and fructose. [28] In addition, nectars have diverse other phytochemicals serving to both attract pollinators and discourage predators. [29] [7] Carbohydrates, amino acids, and volatiles function to attract some species, whereas alkaloids and polyphenols appear to provide a protective function. [29] The Nicotiana attenuata, a tobacco plant native to the US state of Utah, uses several volatile aromas to attract pollinating birds and moths. The strongest such aroma is benzylacetone, but the plant also adds bitter nicotine, which is less aromatic, so may not be detected by the bird until after taking a drink. Researchers speculate the purpose of this addition is to discourage the forager after only a sip, motivating it to visit other plants, therefore maximizing the pollination efficiency gained by the plant for a minimum nectar output. [7] [30] Neurotoxins such as aesculin are present in some nectars such as that of the California buckeye. [31] Nectar contains water, carbohydrates, amino acids, ions and numerous other compounds. [16] [7] [32]

Similar attractive substances

Some insect pollinated plants lack nectaries, but attract pollinators through other secretory structures. Elaiophores are similar to nectaries but are oil secreting. Osmophores are modified structural structures that produce volatile scents. In orchids, these have pheromone qualities. Osmophores have thick domed or papillate epidermis and dense cytoplasm. Platanthera bifolia produces a nocturnal scent from the labellum epidermis. Ophrys labella have dome-shaped, papillate, dark-staining epidermal cells forming osmophores. Narcissus emit pollinator specific volatiles from the corona. [4]

See also

Related Research Articles

<span class="mw-page-title-main">Pollinator</span> Animal that moves pollen from the male anther of a flower to the female stigma

A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.

<span class="mw-page-title-main">Petal</span> Part of most types of flower

Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the corolla. Petals are usually accompanied by another set of modified leaves called sepals, that collectively form the calyx and lie just beneath the corolla. The calyx and the corolla together make up the perianth, the non-reproductive portion of a flower. When the petals and sepals of a flower are difficult to distinguish, they are collectively called tepals. Examples of plants in which the term tepal is appropriate include genera such as Aloe and Tulipa. Conversely, genera such as Rosa and Phaseolus have well-distinguished sepals and petals. When the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly colored tepals. Since they include Liliales, an alternative name is lilioid monocots.

<span class="mw-page-title-main">Pollination</span> Biological process occurring in plants

Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example beetles or butterflies; birds, and bats; water; wind; and even plants themselves. Pollinating animals travel from plant to plant carrying pollen on their bodies in a vital interaction that allows the transfer of genetic material critical to the reproductive system of most flowering plants. When self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work.

<span class="mw-page-title-main">Iridaceae</span> Family of flowering plants comprising irises, gladioli, and crocuses

Iridaceae is a family of plants in order Asparagales, taking its name from the irises. It has a nearly global distribution, with 69 accepted genera with a total of c. 2500 species. It includes a number of economically important cultivated plants, such as species of Freesia, Gladiolus, and Crocus, as well as the crop saffron.

<span class="mw-page-title-main">Pseudocopulation</span> Biological process

Pseudocopulation describes behaviors similar to copulation that serve a reproductive function for one or both participants but do not involve actual sexual union between the individuals. It is most generally applied to a pollinator attempting to copulate with a flower. Some flowers mimic a potential female mate visually, but the key stimuli are often chemical and tactile. This form of mimicry in plants is called Pouyannian mimicry.

<span class="mw-page-title-main">Myrmecophyte</span> Plants that live in association with ants

Myrmecophytes are plants that live in a mutualistic association with a colony of ants. There are over 100 different genera of myrmecophytes. These plants possess structural adaptations that provide ants with food and/or shelter. These specialized structures include domatia, food bodies, and extrafloral nectaries. In exchange for food and shelter, ants aid the myrmecophyte in pollination, seed dispersal, gathering of essential nutrients, and/or defense. Specifically, domatia adapted to ants may be called myrmecodomatia.

<span class="mw-page-title-main">Entomophily</span> Form of pollination by insects

Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Flowers pollinated by insects typically advertise themselves with bright colours, sometimes with conspicuous patterns leading to rewards of pollen and nectar; they may also have an attractive scent which in some cases mimics insect pheromones. Insect pollinators such as bees have adaptations for their role, such as lapping or sucking mouthparts to take in nectar, and in some species also pollen baskets on their hind legs. This required the coevolution of insects and flowering plants in the development of pollination behaviour by the insects and pollination mechanisms by the flowers, benefiting both groups. Both the size and the density of a population are known to affect pollination and subsequent reproductive performance.

<span class="mw-page-title-main">Zoophily</span> Pollination by animals

Zoophily, or zoogamy, is a form of pollination whereby pollen is transferred by animals, usually by invertebrates but in some cases vertebrates, particularly birds and bats, but also by other animals. Zoophilous species frequently have evolved mechanisms to make themselves more appealing to the particular type of pollinator, e.g. brightly colored or scented flowers, nectar, and appealing shapes and patterns. These plant-animal relationships are often mutually beneficial because of the food source provided in exchange for pollination.

<span class="mw-page-title-main">Nectarivore</span> Animal in which nectar is a main source of nutrition in their diet

In zoology, a nectarivore is an animal which derives its energy and nutrient requirements from a diet consisting mainly or exclusively of the sugar-rich nectar produced by flowering plants.

<span class="mw-page-title-main">Ornithophily</span> Pollination by birds

Ornithophily or bird pollination is the pollination of flowering plants by birds. This sometimes coevolutionary association is derived from insect pollination (entomophily) and is particularly well developed in some parts of the world, especially in the tropics, Southern Africa, and on some island chains. The association involves several distinctive plant adaptations forming a "pollination syndrome". The plants typically have colourful, often red, flowers with long tubular structures holding ample nectar and orientations of the stamen and stigma that ensure contact with the pollinator. Birds involved in ornithophily tend to be specialist nectarivores with brushy tongues and long bills, that are either capable of hovering flight or light enough to perch on the flower structures.

<span class="mw-page-title-main">Pollination syndrome</span> Flower traits that attract pollinators

Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic or biotic, such as birds, bees, flies, and so forth through a process called pollinator-mediated selection. These traits include flower shape, size, colour, odour, reward type and amount, nectar composition, timing of flowering, etc. For example, tubular red flowers with copious nectar often attract birds; foul smelling flowers attract carrion flies or beetles, etc.

<span class="mw-page-title-main">Nectar robbing</span> Foraging behavior

Nectar robbing is a foraging behavior used by some organisms that feed on floral nectar, carried out by feeding from holes bitten in flowers, rather than by entering through the flowers' natural openings. Nectar robbers usually feed in this way, avoiding contact with the floral reproductive structures, and therefore do not facilitate plant reproduction via pollination. Because many species that act as pollinators also act as nectar robbers, nectar robbing is considered to be a form of exploitation of plant-pollinator mutualism. While there is variation in the dependency on nectar for robber species, most species rob facultatively.

<span class="mw-page-title-main">Flower constancy</span> Tendency to visit certain flower species

Flower constancy or pollinator constancy is the tendency of individual pollinators to exclusively visit certain flower species or morphs within a species, bypassing other available flower species that could potentially contain more nectar. This type of foraging behavior puts selective pressures on floral traits in a process called pollinator-mediated selection. Flower constancy is different from other types of insect specialization such as innate preferences for certain colors or flower types, or the tendency of pollinators to visit the most rewarding and abundant flowers.

<span class="mw-page-title-main">Tritrophic interactions in plant defense</span> Ecological interactions

Tritrophic interactions in plant defense against herbivory describe the ecological impacts of three trophic levels on each other: the plant, the herbivore, and its natural enemies. They may also be called multitrophic interactions when further trophic levels, such as soil microbes, endophytes, or hyperparasitoids are considered. Tritrophic interactions join pollination and seed dispersal as vital biological functions which plants perform via cooperation with animals.

The tissues that are concerned with the secretion of gums, resins, volatile oils, nectar latex, and other substances in plants are called secretory tissues. These tissues are classified as either laticiferous tissues or glandular tissues.

<i>Hydnophytum formicarum</i> Species of plant

Hydnophytum formicarum, commonly called a "Baboon's head" or "Ant plant", is an epiphyte native to Southeast Asia and is considered critically endangered in Singapore. It is a myrmecophyte as ants live in its tuber, also known as a caudex, and pollinate its flowers. It resides in open-canopied areas, rainforests, and terrestrial regions of high elevation.

<span class="mw-page-title-main">Floral scent</span>

Floral scent, or flower scent, is composed of all the volatile organic compounds (VOCs), or aroma compounds, emitted by floral tissue. Other names for floral scent include, aroma, fragrance, floral odour or perfume. Flower scent of most flowering plant species encompasses a diversity of VOCs, sometimes up to several hundred different compounds. The primary functions of floral scent are to deter herbivores and especially folivorous insects, and to attract pollinators. Floral scent is one of the most important communication channels mediating plant-pollinator interactions, along with visual cues.

<span class="mw-page-title-main">Nectar spur</span>

A nectar spur is a hollow extension of a part of a flower. The spur may arise from various parts of the flower: the sepals, petals, or hypanthium, and often contain tissues that secrete nectar (nectaries). Nectar spurs are present in many clades across the angiosperms, and are often cited as an example of convergent evolution.

<span class="mw-page-title-main">Monocotyledon reproduction</span> Flowering plant reproduction system

The monocots are one of the two major groups of flowering plants, the other being the dicots. In order to reproduce they utilize various strategies such as employing forms of asexual reproduction, restricting which individuals they are sexually compatible with, or influencing how they are pollinated. Nearly all reproductive strategies that evolved in the dicots have independently evolved in monocots as well. Despite these similarities and their close relatedness, monocots and dicots have distinct traits in their reproductive biologies.

<span class="mw-page-title-main">UV coloration in flowers</span> Natural phenomenon

UV coloration is a natural phenomenon that leads to unique interactions between organisms that have evolved the ability to perceive these wavelengths of light. It serves as one method to attract pollinators to the flower along with scent, shape, and nectar quality. Flowers are known for their range of visible colors that humans can see with their eyes and observe an array of different shades and patterns. The naked eye cannot see the ultraviolet coloration many flowers employ to bring attention to themselves. By either reflecting or absorbing UV light waves, flowers are able to communicate with pollinators. This allows plants that may require an animal pollinator to stand out from other flowers or distinguish where their flowers are in a muddied background of other plant parts. For the plant, it is important to share and receive pollen so they can reproduce, maintain their ecological role, and guide the evolutionary history of the population.

References

  1. ↑ "Killer Bees". www.columbia.edu. Retrieved 17 January 2022.
  2. ↑ Koptur, S.; Palacios-Rios, M.; Díaz-Castelazo, C.; MacKay, W. P.; Rico-Gray, V. (2013). "Nectar secretion on fern fronds associated with lower levels of herbivore damage: Field experiments with a widespread epiphyte of Mexican cloud forest remnants". Annals of Botany. 111 (6): 1277–1283. doi:10.1093/aob/mct063. PMC   3662509 . PMID   23609022.
  3. 1 2 "Nectar". Online Etymology Dictionary, Douglas Harper. 2018. Retrieved 28 May 2018.
  4. 1 2 3 4 Rudall 2007, pp. 96–98.
  5. ↑ Nicolson et al 2017, p. 41.
  6. 1 2 Willmer, Pat. Pollination and floral ecology. Princeton University Press, 2011.[ page needed ][ ISBN missing ]
  7. 1 2 3 4 Nicolson et al 2017.
  8. ↑ Fahn, Abraham (1952). "On the Structure of Floral Nectaries". Botanical Gazette. 113 (4): 464–470. doi:10.1086/335735. JSTOR   2472434. S2CID   85332036.
  9. ↑ Wallace, Gary D. (February 1977). "Studies of the Monotropoideae (Ericaceae). Floral Nectaries: Anatomy and Function in Pollination Ecology". American Journal of Botany. 64 (2): 199–206. doi:10.1002/j.1537-2197.1977.tb15719.x.
  10. ↑ Heil, Martin (April 2011). "Nectar: generation, regulation and ecological functions". Trends in Plant Science. 16 (4): 191–200. doi: 10.1016/j.tplants.2011.01.003 . PMID   21345715. S2CID   11206264.
  11. ↑ Pacini, E.; Nepi, M.; Vesprini, J. L. (May 2003). "Nectar biodiversity: a short review". Plant Systematics and Evolution. 238 (1–4): 7–21. Bibcode:2003PSyEv.238....7P. doi:10.1007/s00606-002-0277-y. S2CID   29016446.
  12. ↑ Thornburg, R. W.; Carter, C.; Powell, A.; Mittler, R.; Rizhsky, L.; Horner, H. T. (May 2003). "A major function of the tobacco floral nectary is defense against microbial attack". Plant Systematics and Evolution. 238 (1–4): 211–218. Bibcode:2003PSyEv.238..211T. doi:10.1007/s00606-003-0282-9. S2CID   19339791.
  13. ↑ Stein, Bruce A.; Tobe, Hiroshi (1989). "Floral Nectaries in Melastomataceae and Their Systematic and Evolutionary Implications". Annals of the Missouri Botanical Garden. 76 (2): 519–531. doi:10.2307/2399498. JSTOR   2399498. INIST   6608807.
  14. ↑ Sajo, M. G.; Rudall, P. J.; Prychid, C. J. (August 2004). "Floral anatomy of Bromeliaceae, with particular reference to the evolution of epigyny and septal nectaries in commelinid monocots". Plant Systematics and Evolution. 247 (3–4). doi:10.1007/s00606-002-0143-0. S2CID   20457047.
  15. ↑ Rudall, Paula J.; Manning, John C.; Goldblatt, Peter (2003). "Evolution of Floral Nectaries in Iridaceae". Annals of the Missouri Botanical Garden. 90 (4): 613–631. doi:10.2307/3298546. JSTOR   3298546.
  16. 1 2 Thornburg 2001.
  17. ↑ Corbet, Sarah A. (1 January 2003). "Nectar sugar content: estimating standing crop and secretion rate in the field". Apidologie. 34 (1): 1–10. doi: 10.1051/apido:2002049 . ISSN   0044-8435.
  18. ↑ Pleasants, John M.; Zimmerman, Michael (1 August 1979). "Patchiness in the dispersion of nectar resources: Evidence for hot and cold spots". Oecologia. 41 (3): 283–288. Bibcode:1979Oecol..41..283P. doi:10.1007/BF00377432. ISSN   1432-1939. PMID   28309765. S2CID   41950102.
  19. ↑ Geest, Emily A.; Baum, Kristen A. (2022). "The Impact of Fire on Nectar Quality and Quantity for Insect Pollinator Communities". The American Midland Naturalist. 187 (2): 268–278. doi:10.1674/0003-0031-187.2.268. ISSN   0003-0031. S2CID   248300845.
  20. 1 2 3 4 Rudall 2007, pp. 66–68.
  21. 1 2 Heil, M.; Fiala, B.; Baumann, B.; Linsenmair, K.E. (2000). "Temporal, spatial and biotic variations in extrafloral nectar secretion by Macaranga tanarius". Functional Ecology. 14 (6): 749. Bibcode:2000FuEco..14..749M. doi:10.1046/j.1365-2435.2000.00480.x.
  22. 1 2 3 4 5 Weber, M. G.; Keeler, K. H. (2012). "The phylogenetic distribution of extrafloral nectaries in plants". Annals of Botany. 111 (6): 1251–1261. doi:10.1093/aob/mcs225. PMC   3662505 . PMID   23087129.
  23. ↑ Plant-Provided Food for Carnivorous Insects – Cambridge University Press
  24. 1 2 Sezen, Uzay. "Ants defending extrafloral nectaries of the passion flower (Passiflora incarnata)" . Retrieved 6 January 2012.
  25. ↑ Merbach, M. 2001. Nectaries in Nepenthes. In: C.M. Clarke Nepenthes of Sumatra and Peninsular Malaysia . Natural History Publications (Borneo), Kota Kinabalu.[ page needed ]
  26. 1 2 Mancuso, S. (2010). "Federico Delpino and the foundation of plant biology". Plant Signaling & Behavior. 5 (9): 1067–1071. Bibcode:2010PlSiB...5.1067M. doi:10.4161/psb.5.9.12102. PMC   3115070 . PMID   21490417.
  27. ↑ Nectaries in ferns: their taxonomic distribution, structure, function, and sugar composition
  28. ↑ Chalcoff, Vanina (March 2006). "Nectar Concentration and Composition of 26 Species from the Temperate Forest of South America". Annals of Botany. 97 (3): 413–421. doi:10.1093/aob/mcj043. PMC   2803636 . PMID   16373370.
  29. 1 2 González-Teuber, M.; Heil, M. (2009). "Nectar chemistry is tailored for both attraction of mutualists and protection from exploiters". Plant Signaling & Behavior. 4 (9): 809–813. Bibcode:2009PlSiB...4..809G. doi:10.4161/psb.4.9.9393. PMC   2802787 . PMID   19847105.
  30. ↑ Everts, Sarah (1 September 2008). "Two-Faced Flowers". Chemical & Engineering News.
  31. ↑ C.Michael Hogan (2008) Aesculus californica, Globaltwitcher.com, ed. N. Stromberg
  32. ↑ Park & Thornburg 2009.

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