28-559: Whitethorn or white thorn may refer to: Plants [ edit ] Acacia constricta , known as whitethorn acacia, a shrub in the family Fabaceae Bursaria spinosa , a small shrub in the family Pittosporaceae Ceanothus leucodermis , a shrub in the family Rhamnaceae Crataegus monogyna , the common hawthorn, a small tree in the family Rosaceae Crataegus punctata Other [ edit ] Whitethorn, California , United States Whitethorn (Blacksburg, Virginia) , U.S.,
56-405: A vascular strand in the nectary to assist in transport over a longer distance. 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 . Nectar from floral nectaries is sometimes used as
84-410: A historic house Whitethorn Woods , 2006 novel by Maeve Binchy Whitethorn (novel) , a 2005 novel by Bryce Courtenay See also [ edit ] Whyte Thorne Blackthorn (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Whitethorn . If an internal link led you here, you may wish to change
112-427: A modified part or a novel structure. The different types of floral nectaries include: 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
140-406: 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
168-617: 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 . Among passion flowers , for example, extrafloral nectaries prevent herbivores by attracting ants and deterring two species of butterflies from laying eggs. In many carnivorous plants , extrafloral nectaries are also used to attract insect prey . Charles Darwin understood that extrafloral nectar "though small in quantity,
196-446: A primary food source. In turn, these wasps then hunt agricultural pest insects as food for their young. Nectar is most often associated with flowering plants angiosperms , but it is also produced by other groups, including ferns . Nectar is derived from Greek νέκταρ , the fabled drink of eternal life. Some derive the word from νε- or νη- "not" plus κτα- or κτεν- "kill" , meaning "unkillable", thus "immortal". The common use of
224-459: A protective function. 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
252-433: 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. Different characteristics of the spur, such as its length or position in
280-508: A second round of blooms in July–October. Blooming requires a minimum amount of rain, followed by a period of warmth. Vachellia constricta typically grows to 2 metres (6.6 ft) in height, occasionally reaching 6 metres (20 ft). Its stems range from a light gray to a mahogany color, with pairs of straight white spines anywhere from 0.5 to 2 cm long. The small leaves are even- pinnate , usually 2.5–4 cm in length, with each of
308-446: Is cultivated by specialty plant nurseries as an ornamental plant . It is used in native plant desert habitat gardens. It can be trained as a small tree or grown as a barrier hedges . Nectar#Extrafloral nectaries Nectar is a viscous , sugar -rich liquid produced by plants in glands called nectaries , either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries , which provide
SECTION 10
#1732848813053336-907: Is greedily sought by insects" but believed that "their visits do not in any way benefit the plant". 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. 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
364-499: Is particularly rich in carbohydrates, proteins and lipids. 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. In contrast to floral nectaries, nectar produced outside the flower generally has a defensive function. The nectar attracts predatory insects which will eat both the nectar and any plant-eating insects around, thus functioning as "bodyguards". Foraging predatory insects show
392-1216: Is variable due to many factors, including flower age, plant location, and habitat management. 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 . 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
420-854: The Cenozoic , with weak support for a role played by arthropod herbivore diversifications. They are absent in bryophytes , gymnosperms , early angiosperms , magnoliids , and members of Apiales among the eudicots. 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. The main ingredients in nectar are sugars in varying proportions of sucrose , glucose , and fructose . In addition, nectars have diverse other phytochemicals serving to both attract pollinators and discourage predators. Carbohydrates , amino acids , and volatiles function to attract some species, whereas alkaloids and polyphenols appear to provide
448-584: The gynoecium from certain pathogens. 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
476-838: The whitethorn acacia , is a shrub native to Mexico and the Southwestern United States . In the Southwest V. constricta grows in the southern half of Arizona , extending into New Mexico and West Texas . It grows in Mexico as far south as Oaxaca , with small disjunct populations in Baja California and in the Magdalena Plain of Baja California Sur . In the Sonoran Desert , Vachellia constricta grows in arroyos and washes, where it blooms in late spring (April–May), with
504-539: The 3–9 pairs of pinnae made of 4–16 pairs of leaflets, which are about 3.5 mm long and 1 mm wide. The flowers occur in small yellow balls about 1 cm in diameter. The flowers offer no nectar and little pollen, and so tend to have few visitors. Extrafloral nectaries grow along the main stem of the compound leaves and attract ants to the trees. The seed pods are relatively long and thin, up to 12 cm long but only 3–6 mm wide. The leaves may drop in response to either dryness or cold. Vachellia constricta
532-488: The divergent evolution of the African honey bee, A. m. scutellata and the western honey bee . 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
560-439: The flower, may determine the type of pollinator that visits the flower. 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
588-834: 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. Neurotoxins such as aesculin are present in some nectars such as that of the California buckeye . Nectar contains water, essential oils , carbohydrates , amino acids , ions , and numerous other compounds. 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
SECTION 20
#1732848813053616-897: 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). Other genera with extrafloral nectaries include Salix ( Salicaceae ), Prunus ( Rosaceae ) and Gossypium ( Malvaceae ). 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 . Fern nectaries appear to have evolved around 135 million years ago, nearly simultaneously with angiosperms. However, fern nectaries did not diversify remarkably until nearly 100 million years later, in
644-497: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Whitethorn&oldid=1153826314 " Categories : Disambiguation pages Plant common name disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Acacia constricta Acacia constricta Benth. Vachellia constricta , also known commonly as
672-454: The nectar to attract pollinators that consume the nectar, such as birds and butterflies . 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. In flowers that are generally pollinated by a long-tongued organism such as certain flies , moths , butterflies, and birds, nectaries in
700-428: 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. Nectar secretion increases as the flower is visited by pollinators. After pollination, the nectar is frequently reabsorbed into the plant. The amount of nectar in flowers at any given time
728-476: 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 . The adjacent subepidermal cells may also be secretory. Flowers that have longer nectaries sometimes have
756-436: The surface of the gynoecium. Nectaries may also vary in color, number, and symmetry. 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. The different types of floral nectaries coevolved depending on
784-611: The word "nectar" to refer to the "sweet liquid in flowers", is first recorded in AD 1600. A nectary or honey gland 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
#52947