Contents 1 The structure and formation of pollen 1.1 Formation 1.2 Structure 2 Pollination 3 Pollen in the fossil record 4 Allergy to pollen 4.1 Treatment 5 Nutrition 5.1 In humans 5.2 Parasites 6 Forensic palynology 7 See also 8 References 9 Bibliography 10 External links


The structure and formation of pollen[edit] Triporate pollen of Oenothera speciosa Pollen of Lilium auratum showing single sulcus (monosulcate) Arabis pollen has three colpi and prominent surface structure. Pollens/Microspores of Lycopersicon esculentum at coenocytic tetrad stage of development observed through oil immersion microscope; the chromosomes of what will become four pollen grains can be seen. Apple pollen under microscopy Pollen itself is not the male gamete.[1] Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm cells. Formation[edit] Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower. Pollen grains come in a wide variety of shapes, sizes, and surface markings characteristic of the species (see electron micrograph, right). Pollen grains of pines, firs, and spruces are winged. The smallest pollen grain, that of the forget-me-not (Myosotis spp.),[which?] is around 6 µm (0.006 mm) in diameter.[citation needed] Wind-borne pollen grains can be as large as about 90–100 µm.[2] In angiosperms, during flower development the anther is composed of a mass of cells that appear undifferentiated, except for a partially differentiated dermis. As the flower develops, four groups of sporogenous cells form within the anther. The fertile sporogenous cells are surrounded by layers of sterile cells that grow into the wall of the pollen sac. Some of the cells grow into nutritive cells that supply nutrition for the microspores that form by meiotic division from the sporogenous cells. In a process called microsporogenesis, four haploid microspores are produced from each diploid sporogenous cell (microsporocyte, pollen mother cell or meiocyte), after meiotic division. After the formation of the four microspores, which are contained by callose walls, the development of the pollen grain walls begins. The callose wall is broken down by an enzyme called callase and the freed pollen grains grow in size and develop their characteristic shape and form a resistant outer wall called the exine and an inner wall called the intine. The exine is what is preserved in the fossil record. Two basic types of microsporogenesis are recognised, simultaneous and successive. In simultaneous microsporogenesis meiotic steps I and II are completed prior to cytokinesis, whereas in successive microsporogenesis cytokinesis follows. While there may be a continuum with intermediate forms, the type of microsporogenesis has systematic significance. The predominant form amongst the monocots is successive, but there are important exceptions.[3] During microgametogenesis, the unicellular microspores undergo mitosis and develop into mature microgametophytes containing the gametes.[4] In some flowering plants,[which?] germination of the pollen grain may begin even before it leaves the microsporangium, with the generative cell forming the two sperm cells. Structure[edit] Except in the case of some submerged aquatic plants, the mature pollen grain has a double wall. The vegetative and generative cells are surrounded by a thin delicate wall of unaltered cellulose called the endospore or intine, and a tough resistant outer cuticularized wall composed largely of sporopollenin called the exospore or exine. The exine often bears spines or warts, or is variously sculptured, and the character of the markings is often of value for identifying genus, species, or even cultivar or individual. The spines may be less than a micron in length (spinulus, plural spinuli) referred to as spinulose (scabrate), or longer than a micron (echina, echinae) referred to as echinate. Various terms also describe the sculpturing such as reticulate, a net like appearance consisting of elements (murus, muri) separated from each other by a lumen (plural lumina). The pollen wall protects the sperm while the pollen grain is moving from the anther to the stigma; it protects the vital genetic material from drying out and solar radiation. The pollen grain surface is covered with waxes and proteins, which are held in place by structures called sculpture elements on the surface of the grain. The outer pollen wall, which prevents the pollen grain from shrinking and crushing the genetic material during desiccation, is composed of two layers. These two layers are the tectum and the foot layer, which is just above the intine. The tectum and foot layer are separated by a region called the columella, which is composed of strengthening rods. The outer wall is constructed with a resistant biopolymer called sporopollenin. Pollen apertures are regions of the pollen wall that may involve exine thinning or a significant reduction in exine thickness.[5] They allow shrinking and swelling of the grain caused by changes in moisture content. Elongated apertures or furrows in the pollen grain are called colpi (singular: colpus) or sulci (singular: sulcus). Apertures that are more circular are called pores. Colpi, sulci and pores are major features in the identification of classes of pollen.[6] Pollen may be referred to as inaperturate (apertures absent) or aperturate (apertures present). The aperture may have a lid (operculum), hence is described as operculate.[7] However the term inaperturate covers a wide range of morphological types, such as functionally inaperturate (cryptoaperturate) and omniaperturate.[3] Inaperaturate pollen grains often have thin walls, which facilitates pollen tube germination at any position.[5] Terms such as uniaperturate and triaperturate refer to the number of apertures present (one and three respectively). The orientation of furrows (relative to the original tetrad of microspores) classifies the pollen as sulcate or colpate. Sulcate pollen has a furrow across the middle of what was the outer face when the pollen grain was in its tetrad.[8] If the pollen has only a single sulcus, it is described as monosulcate, has two sulci, as bisulcate, or more, as polysulcate.[9][10] Colpate pollen has furrows other than across the middle of the outer faces.[8] Eudicots have pollen with three colpi (tricolpate) or with shapes that are evolutionarily derived from tricolpate pollen.[11] The evolutionary trend in plants has been from monosulcate to polycolpate or polyporate pollen.[8]


Pollination[edit] Main article: Pollination European honey bee carrying pollen in a pollen basket back to the hive Marmalade hoverfly, pollen on its face and legs, sitting on a rockrose. Diadasia bee straddles flower carpels while visiting yellow Opuntia engelmannii cactus The transfer of pollen grains to the female reproductive structure (pistil in angiosperms) is called pollination. This transfer can be mediated by the wind, in which case the plant is described as anemophilous (literally wind-loving). Anemophilous plants typically produce great quantities of very lightweight pollen grains, sometimes with air-sacs. Non-flowering seed plants (e.g. pine trees) are characteristically anemophilous. Anemophilous flowering plants generally have inconspicuous flowers. Entomophilous (literally insect-loving) plants produce pollen that is relatively heavy, sticky and protein-rich, for dispersal by insect pollinators attracted to their flowers. Many insects and some mites are specialized to feed on pollen, and are called palynivores. In non-flowering seed plants, pollen germinates in the pollen chamber, located beneath the micropyle, underneath the integuments of the ovule. A pollen tube is produced, which grows into the nucellus to provide nutrients for the developing sperm cells. Sperm cells of Pinophyta and Gnetophyta are without flagella, and are carried by the pollen tube, while those of Cycadophyta and Ginkgophyta have many flagella. When placed on the stigma of a flowering plant, under favorable circumstances, a pollen grain puts forth a pollen tube, which grows down the tissue of the style to the ovary, and makes its way along the placenta, guided by projections or hairs, to the micropyle of an ovule. The nucleus of the tube cell has meanwhile passed into the tube, as does also the generative nucleus, which divides (if it hasn't already) to form two sperm cells. The sperm cells are carried to their destination in the tip of the pollen tube. Double-strand breaks in DNA that arise during pollen tube growth appear to be efficiently repaired in the generative cell that carries the male genomic information to be passed on to the next plant generation.[12] However, the vegetative cell that is responsible for tube elongation appears to lack this DNA repair capability.[12]


Pollen in the fossil record[edit] Main article: Palynology Pollen's sporopollenin outer sheath affords it some resistance to the rigours of the fossilisation process that destroy weaker objects; it is also produced in huge quantities. There is an extensive fossil record of pollen grains, often disassociated from their parent plant. The discipline of palynology is devoted to the study of pollen, which can be used both for biostratigraphy and to gain information about the abundance and variety of plants alive — which can itself yield important information about paleoclimates. Pollen is first found in the fossil record in the late Devonian period[verification needed] and increases in abundance until the present day.


Allergy to pollen[edit] See also: Allergy season This section has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. (September 2010) (Learn how and when to remove this template message) This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2013) (Learn how and when to remove this template message) This section needs expansion with: information about allergies not in the nose, e.g., skin reactions. You can help by adding to it. (March 2013) (Learn how and when to remove this template message) Nasal allergy to pollen is called pollinosis, and allergy specifically to grass pollen is called hay fever. Generally, pollens that cause allergies are those of anemophilous plants (pollen is dispersed by air currents.) Such plants produce large quantities of lightweight pollen (because wind dispersal is random and the likelihood of one pollen grain landing on another flower is small), which can be carried for great distances and are easily inhaled, bringing it into contact with the sensitive nasal passages. In the US, people often mistakenly blame the conspicuous goldenrod flower for allergies. Since this plant is entomophilous (its pollen is dispersed by animals), its heavy, sticky pollen does not become independently airborne. Most late summer and fall pollen allergies are probably caused by ragweed, a widespread anemophilous plant.[13] Arizona was once regarded as a haven for people with pollen allergies, although several ragweed species grow in the desert. However, as suburbs grew and people began establishing irrigated lawns and gardens, more irritating species of ragweed gained a foothold and Arizona lost its claim of freedom from hay fever. Anemophilous spring blooming plants such as oak, birch, hickory, pecan, and early summer grasses may also induce pollen allergies. Most cultivated plants with showy flowers are entomophilous and do not cause pollen allergies. The number of people in the United States affected by hay fever is between 20 and 40 million,[14] and such allergy has proven to be the most frequent allergic response in the nation. There are certain evidential suggestions pointing out hay fever and similar allergies to be of hereditary origin. Individuals who suffer from eczema or are asthmatic tend to be more susceptible to developing long-term hay fever.[15] In Denmark, decades of rising temperatures cause pollen to appear earlier and in greater numbers, as well as introduction of new species such as ragweed.[16] The most efficient way to handle a pollen allergy is by preventing contact with the material. Individuals carrying the ailment may at first believe that they have a simple summer cold, but hay fever becomes more evident when the apparent cold does not disappear. The confirmation of hay fever can be obtained after examination by a general physician.[17] Treatment[edit] Main article: Allergic rhinitis § treatment Antihistamines are effective at treating mild cases of pollinosis, this type of non-prescribed drugs includes loratadine, cetirizine and chlorpheniramine. They do not prevent the discharge of histamine, but it has been proven that they do prevent a part of the chain reaction activated by this biogenic amine, which considerably lowers hay fever symptoms. Decongestants can be administered in different ways such as tablets and nasal sprays. Allergy immunotherapy (AIT) treatment involves administering doses of allergens to accustom the body to pollen, thereby inducing specific long-term tolerance.[18] Allergy immunotherapy can be administered orally (as sublingual tablets or sublingual drops), or by injections under the skin (subcutaneous). Discovered by Leonard Noon and John Freeman in 1911, allergy immunotherapy represents the only causative treatment for respiratory allergies.


Nutrition[edit] Most major classes of predatory and parasitic arthropods contain species that eat pollen, despite the common perception that bees are the primary pollen-consuming arthropod group. Many other Hymenoptera other than bees consume pollen as adults, though only a small number feed on pollen as larvae (including some ant larvae). Spiders are normally considered carnivores but pollen is an important source of food for several species, particularly for spiderlings, which catch pollen on their webs. It is not clear how spiderlings manage to eat pollen however, since their mouths are not large enough to consume pollen grains.[citation needed] Some predatory mites also feed on pollen, with some species being able to subsist solely on pollen, such as Euseius tularensis, which feeds on the pollen of dozens of plant species. Members of some beetle families such as Mordellidae and Melyridae feed almost exclusively on pollen as adults, while various lineages within larger families such as Curculionidae, Chrysomelidae, Cerambycidae, and Scarabaeidae are pollen specialists even though most members of their families are not (e.g., only 36 of 40000 species of ground beetles, which are typically predatory, have been shown to eat pollen—but this is thought to be a severe underestimate as the feeding habits are only known for 1000 species). Similarly, Ladybird beetles mainly eat insects, but many species also eat pollen, as either part or all of their diet. Hemiptera are mostly herbivores or omnivores but pollen feeding is known (and has only been well studied in the Anthocoridae). Many adult flies, especially Syrphidae, feed on pollen, and three UK syrphid species feed strictly on pollen (syrphids, like all flies, cannot eat pollen directly due to the structure of their mouthparts, but can consume pollen contents that are dissolved in a fluid).[19] Some species of fungus, including Fomes fomentarius, are able to break down grains of pollen as a secondary nutrition source that is particularly high in nitrogen.[20] Pollen may be valuable diet supplement for detritivores, providing them with nutrients needed for growth, development and maturation.[21] It was suggested that obtaining nutrients from pollen, deposited on the forest floor during periods of pollen rains, allows fungi to decompose nutritionally scarce litter.[21] Some species of Heliconius butterflies consume pollen as adults, which appears to be a valuable nutrient source, and these species are more distasteful to predators than the non-pollen consuming species.[22][23] Although bats, butterflies and hummingbirds are not pollen eaters per se, their consumption of nectar in flowers is an important aspect of the pollination process. In humans[edit] A variety of producers have started selling bee pollen for human consumption, often marketed as a food (rather than a dietary supplement). The largest constituent is carbohydrates, with protein content ranging from 7 to 35 percent depending on the plant species collected by bees.[24] Honey produced by bees from natural sources contains pollen derived p-coumaric acid, an antioxidant.[25] The U.S. Food and Drug Administration (FDA) has not found any harmful effects of bee pollen consumption, except from the usual allergies. However, FDA does not allow bee pollen marketers in the United States to make health claims about their produce, as no scientific basis for these has ever been proven. Furthermore, there are possible dangers not only from allergic reactions but also from contaminants such as pesticides and from fungi and bacteria growth related to poor storage procedures. A manufacturers's claim that pollen collecting helps the bee colonies is also controversial.[26] Pine pollen (송화가루; Songhwa Garu) is traditionally consumed in Korea as an ingredient in sweets and beverages. Parasites[edit] The growing industries in pollen harvesting for human and bee consumption rely on harvesting pollen baskets from honey bees as they return to their hives using a pollen trap.[27] When this pollen has been tested for parasites, it has been found that a multitude of pollinator viruses and eukaryotic parasites are present in the pollen.[28][29] It is currently unclear if the parasites are introduced by the bee that collected the pollen or if it is from contamination to the flower.[29][30] Though this is not likely to pose a risk to humans, it is a major issue for the bumblebee rearing industry that relies on thousands of tonnes of honey bee collected pollen per year.[31] Several sterilization methods have been employed, though no method has been 100% effective at sterilizing, without reducing the nutritional value, of the pollen [32]


Forensic palynology[edit] Main article: Forensic palynology An SEM micrograph of Redbud pollen. Scanning electron microscopes are major instruments in palynology. In forensic biology, pollen can tell a lot about where a person or object has been, because regions of the world, or even more particular locations such a certain set of bushes, will have a distinctive collection of pollen species.[33] Pollen evidence can also reveal the season in which a particular object picked up the pollen.[34] Pollen has been used to trace activity at mass graves in Bosnia,[35] catch a burglar who brushed against a Hypericum bush during a crime,[36] and has even been proposed as an additive for bullets to enable tracking them.[37]


See also[edit] European Pollen Database Evolution of sex Microsporangia Pollen calendar Pollen count Pollen source Polyphenol antioxidant Palynology


References[edit] ^ Johnstone, Adam (2001). Biology: facts & practice for A level. Oxford University Press. p. 95. ISBN 0-19-914766-3.  ^ Pleasants, J. M.; Hellmich, R. L.; Dively, G. P.; Sears, M. K.; Stanley-Horn, D. E.; Mattila, H. R.; Foster, J. E.; Clark, P.; Jones, G. D. (2001). "Corn pollen deposition on milkweeds in and near cornfields". Proceedings of the National Academy of Sciences of the United States of America. 98 (21): 11919–24. doi:10.1073/pnas.211287498. PMC 59743 . PMID 11559840.  ^ a b Furness, Carol A.; Rudall, Paula J. (January 2001). "Pollen and anther characters in monocot systematics". Grana. 40 (1–2): 17–25. doi:10.1080/00173130152591840.  ^ Pollen Development — University of Leicester ^ a b Furness, Carol A.; Rudall, Paula J. (2004-03-01). "Pollen aperture evolution--a crucial factor for eudicot success?". Trends in Plant Science. 9 (3): 154–158. doi:10.1016/j.tplants.2004.01.001. PMID 15003239.  ^ Davis, Owen. "Aperture". geo.arizona.edu.  ^ Furness, Carol A.; Rudall, Paula J. (November 2003). "Apertures with Lids: Distribution and Significance of Operculate Pollen in Monocotyledons". International Journal of Plant Sciences. 164 (6): 835–854. doi:10.1086/378656.  ^ a b c Sporne, Kenneth R. (1972). "Some Observations on the Evolution of Pollen Types in Dicotyledons". New Phytologist. 71 (1): 181–185. doi:10.1111/j.1469-8137.1972.tb04826.x.  ^ Simpson, Michael G. (2011). "Palynology". Plant Systematics. Academic Press. pp. 453–464. ISBN 978-0-08-051404-8. Retrieved 6 January 2014.  ^ Singh, Gurcharan (2004-01-01). "Palynology". Plant Systematics: An Integrated Approach. p. 142. ISBN 9781578083510. Retrieved 23 January 2014.  In Singh (2004). ^ Judd, Walter S. & Olmstead, Richard G. (2004). "A survey of tricolpate (eudicot) phylogenetic relationships". American Journal of Botany. 91 (10): 1627–1644. doi:10.3732/ajb.91.10.1627. PMID 21652313.  ^ a b Hirano T, Takagi K, Hoshino Y, Abe T (2013). "DNA damage response in male gametes of Cyrtanthus mackenii during pollen tube growth". AoB Plants. 5: plt004. doi:10.1093/aobpla/plt004. PMC 3583183 . PMID 23550213.  ^ Oder, Tom. "Dear allergy sufferers: Don't blame goldenrod". mnn.com. Mother Nature Network. Retrieved 18 July 2016.  ^ Skoner, DP (July 2001). "Allergic rhinitis: definition, epidemiology, pathophysiology, detection, and diagnosis". The Journal of Allergy and Clinical Immunology. 108 (1 Suppl): S2–8. PMID 11449200.  ^ Allergies and Hay Fever WebMD. Retrieved on 2010-03-09 ^ Siewertsen, Bjarne. "Hård nyser for allergikere i varm fremtid" (English: Hard sneeze for allergic people in warm future) Danish Meteorological Institute, 18 April 2015. Retrieved: 19 April 2015. ^ Bee, grass pollen allergy symptoms. allergiesandtreatments.com. Retrieved on 2010-03-09 ^ Van Overtvelt L. et al. Immune mechanisms of allergen-specific sublingual immunotherapy. Revue française d'allergologie et d'immunologie clinique. 2006; 46: 713–720. ^ "The Pollen Feeders". Relationships of Natural Enemies and Non-Prey Foods. 7. 2009. pp. 87–11. doi:10.1007/978-1-4020-9235-0_6. ISBN 978-1-4020-9234-3.  ^ Schwarze, Francis W. M. R.; Engels, Julia; Mattheck, Claus (2000). Fungal Strategies of Wood Decay in Trees. Springer. p. 61. ISBN 978-3-540-67205-0. CS1 maint: Multiple names: authors list (link) ^ a b Filipiak, Michał (2016-01-01). "Pollen Stoichiometry May Influence Detrital Terrestrial and Aquatic Food Webs". Behavioral and Evolutionary Ecology: 138. doi:10.3389/fevo.2016.00138.  ^ Salcledo, Christian. "Evidence of Pollen Digestion at Nocturnal Aggregations of Heliconius Sara in Costa Rica (Lepidoptera: Nymphalidae)." Trop. Lepid. Res. 20.1 (2010): 35–37. Web. ^ Cardoso MZ, Gilbert LE; Gilbert (June 2013). "Pollen feeding, resource allocation and the evolution of chemical defence in passion vine butterflies". Journal of Evolutionary Biology. 26 (6): 1254–60. doi:10.1111/jeb.12119. PMID 23662837.  ^ Sanford, Malcolm T. "Producing Pollen". Archived from the original on January 13, 2007. Retrieved 2015-07-15. , University of Florida, Institute of Food and Agricultural Sciences; citing P. Witherell, "Other Products of the Hive," Chapter XVIII, The Hive and the Honey Bee, Dadant & Sons, Inc., Hamilton, IL, 1975 ^ Mao W, Schuler MA, Berenbaum MR; Schuler; Berenbaum (May 2013). "Honey constituents up-regulate detoxification and immunity genes in the western honey bee Apis mellifera". Proceedings of the National Academy of Sciences of the United States of America. 110 (22): 8842–6. doi:10.1073/pnas.1303884110. PMC 3670375 . PMID 23630255. CS1 maint: Multiple names: authors list (link) ^ Sanford, Malcolm T. "Producing Pollen". University of Florida, Institute of Food and Agricultural Sciences. Archived from the original on 2007-01-13. Retrieved 2007-08-30. . Document ENY118. Original publication date November 1, 1994. Revised February 1, 1995. Reviewed May 1, 2003. ^ https://www.youtube.com/watch?v=JBP9pw2rNk4 ^ Graystock, Peter; Yates, Kathryn; Evison, Sophie E. F.; Darvill, Ben; Goulson, Dave; Hughes, William O. H. (July 2013). "The Trojan hives: pollinator pathogens, imported and distributed in bumblebee colonies". Journal of Applied Ecology: n/a–n/a. doi:10.1111/1365-2664.12134.  ^ a b Singh, Rajwinder; Levitt, Abby L.; Rajotte, Edwin G.; Holmes, Edward C.; Ostiguy, Nancy; vanEngelsdorp, Dennis; Lipkin, W. Ian; dePamphilis, Claude W.; Toth, Amy L.; Cox-Foster, Diana L.; Traveset, Anna (22 December 2010). "RNA Viruses in Hymenopteran Pollinators: Evidence of Inter-Taxa Virus Transmission via Pollen and Potential Impact on Non-Apis Hymenopteran Species". PLoS ONE. 5 (12): e14357. doi:10.1371/journal.pone.0014357. PMC 3008715 . PMID 21203504.  ^ Graystock, Peter; Goulson, Dave; Hughes, William O. H. (5 August 2015). "Parasites in bloom: flowers aid dispersal and transmission of pollinator parasites within and between bee species". Proceedings of the Royal Society B: Biological Sciences. 282 (1813): 20151371. doi:10.1098/rspb.2015.1371. PMC 4632632 . PMID 26246556.  ^ Graystock, Peter; Blane, Edward J.; McFrederick, Quinn S.; Goulson, Dave; Hughes, William O.H. (October 2015). "Do managed bees drive parasite spread and emergence in wild bees?". International Journal for Parasitology: Parasites and Wildlife. 5: 64–75. doi:10.1016/j.ijppaw.2015.10.001.  ^ Graystock, P.; Jones, J.C.; Pamminger, T.; Parkinson, J.F.; Norman, V.; Blane, E.J.; Rothstein, L.; Wäckers, F.; Goulson, D.; Hughes, W.O.H. (May 2016). "Hygienic food to reduce pathogen risk to bumblebees". Journal of Invertebrate Pathology. 136: 68–73. doi:10.1016/j.jip.2016.03.007. PMID 26970260.  ^ Bryant, Vaughn M. "Forensic Palynology: A New Way to Catch Crooks". crimeandclues.com. Archived from the original on 2007-02-03.  ^ Stackhouse, Robert (17 April 2003). "Forensics studies look to pollen". The Battalion.  ^ Wood, Peter (9 September 2004). "Pollen helps war crime forensics". BBC News.  ^ D. Mildenhall (2006). "Hypericum pollen determines the presence of burglars at the scene of a crime: An example of forensic palynology". Forensic Science International. 163 (3): 231–235. doi:10.1016/j.forsciint.2005.11.028. PMID 16406430.  ^ Wolf, Lauren K. (18 August 2008). "Newscripts". Chemical & Engineering News. 86 (33): 88. doi:10.1021/cen-v086n033.p088. 


Bibliography[edit] Davis, Owen (1999). "Palynology — Pollen". University of Arizona. Department of Geosciences.  Simpson, Michael G. (2011). Plant Systematics. Academic Press. ISBN 0-08-051404-9. Retrieved 12 February 2014.  Singh, Gurcharan (2004). Plant Systematics: An Integrated Approach. Science Publishers. ISBN 1-57808-351-6. Retrieved 23 January 2014. 


External links[edit] Wikimedia Commons has media related to Pollen. Pollen and Spore Identification Literature Pollen micrographs at SEM and confocal microscope The flight of a pollen cloud PalDat (database comprising palynological data from a variety of plant families) YouTube video of pollen clouds from Juncus gerardii plants  This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "article name needed". Encyclopædia Britannica (11th ed.). Cambridge University Press.  v t e Botany History of botany Subdisciplines Plant systematics Ethnobotany Paleobotany Plant anatomy Plant ecology Phytogeography Geobotany Flora Phytochemistry Plant pathology Bryology Phycology Floristics Dendrology Plant groups Algae Archaeplastida Bryophyte Non-vascular plants Vascular plants Spermatophytes Pteridophyte Gymnosperm Angiosperm Plant morphology (glossary) Plant cells Cell wall Phragmoplast Plastid Plasmodesma Vacuole Tissues Meristem Vascular tissue Vascular bundle Ground tissue Mesophyll Cork Wood Storage organs Vegetative Root Rhizoid Bulb Rhizome Shoot Stem Leaf Petiole Cataphyll Bud Sessility Reproductive (Flower) Flower development Inflorescence Umbel Raceme Bract Pedicellate Flower Whorl Floral symmetry Floral diagram Floral formula Receptacle Hypanthium (Floral cup) Perianth Tepal Petal Sepal Sporophyll Gynoecium Ovary Ovule Stigma Archegonium Androecium Stamen Staminode Pollen Tapetum Gynandrium Gametophyte Sporophyte Plant embryo Fruit Fruit anatomy Berry Capsule Seed Seed dispersal Endosperm Surface structures Epicuticular wax Plant cuticle Epidermis Stoma Nectary Trichome Prickle Plant physiology Materials Nutrition Photosynthesis Chlorophyll Plant hormone Transpiration Turgor pressure Bulk flow Aleurone Phytomelanin Sugar Sap Starch Cellulose Plant growth and habit Secondary growth Woody plants Herbaceous plants Habit Vines Lianas Shrubs Subshrubs Trees Succulent plants Reproduction Evolution Ecology Alternation of generations Sporangium Spore Microsporangia Microspore Megasporangium Megaspore Pollination Pollinators Pollen tube Double fertilization Germination Evolutionary development Evolutionary history timeline Hardiness zone Plant taxonomy History of plant systematics Herbarium Biological classification Botanical nomenclature Botanical name Correct name Author citation International Code of Nomenclature for algae, fungi, and plants (ICN) - for Cultivated Plants (ICNCP) Taxonomic rank International Association for Plant Taxonomy (IAPT) Plant taxonomy systems Cultivated plant taxonomy Citrus taxonomy cultigen cultivar Group grex Practice Agronomy Floriculture Forestry Horticulture Lists Related topics Botanical terms Botanists by author abbreviation Botanical expedition Category Portal WikiProject Authority control GND: 4046628-0 NDL: 00564471 Retrieved from "https://en.wikipedia.org/w/index.php?title=Pollen&oldid=816643030" Categories: Plant anatomyPlant morphologyPalynologyPollinationAllergologyHidden categories: CS1 maint: Multiple names: authors listAll articles with specifically marked weasel-worded phrasesArticles with specifically marked weasel-worded phrases from February 2017All articles with unsourced statementsArticles with unsourced statements from February 2017All pages needing factual verificationWikipedia articles needing factual verification from July 2007Articles with limited geographic scope from September 2010USA-centricArticles needing additional references from March 2013All articles needing additional referencesArticles to be expanded from March 2013All articles to be expandedArticles using small message boxesArticles with multiple maintenance issuesArticles with unsourced statements from April 2012Articles containing Korean-language textWikipedia articles incorporating a citation from the 1911 Encyclopaedia Britannica with no article parameterWikipedia articles incorporating text from the 1911 Encyclopædia BritannicaWikipedia articles with GND identifiers


Navigation menu Personal tools Not logged inTalkContributionsCreate accountLog in Namespaces ArticleTalk Variants Views ReadEditView history More Search Navigation Main pageContentsFeatured contentCurrent eventsRandom articleDonate to WikipediaWikipedia store Interaction HelpAbout WikipediaCommunity portalRecent changesContact page Tools What links hereRelated changesUpload fileSpecial pagesPermanent linkPage informationWikidata itemCite this page Print/export Create a bookDownload as PDFPrintable version In other projects Wikimedia Commons Languages AfrikaansالعربيةAsturianuAzərbaycancaБашҡортсаБеларускаяБългарскиBosanskiCatalàЧӑвашлаČeštinaCymraegDanskDeutschEestiΕλληνικάEspañolEsperantoEuskaraفارسیFrançaisGaeilgeGàidhligGalego한국어Հայերենहिन्दीHrvatskiIdoBahasa IndonesiaInterlinguaÍslenskaItalianoעבריתҚазақшаKiswahiliLatinaLatviešuLietuviųMagyarМакедонскиമലയാളംBahasa MelayuNederlands日本語NorskNorsk nynorskOccitanOʻzbekcha/ўзбекчаپنجابیPolskiPortuguêsRomânăRuna SimiРусскийScotsSicilianuSimple EnglishSlovenčinaSlovenščinaСрпски / srpskiSrpskohrvatski / српскохрватскиSuomiSvenskaTagalogதமிழ்తెలుగుไทยTürkçeTürkmençeУкраїнськаTiếng Việt中文 Edit links This page was last edited on 22 December 2017, at 18:17. Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. Privacy policy About Wikipedia Disclaimers Contact Wikipedia Developers Cookie statement Mobile view (window.RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgPageParseReport":{"limitreport":{"cputime":"0.740","walltime":"0.883","ppvisitednodes":{"value":3806,"limit":1000000},"ppgeneratednodes":{"value":0,"limit":1500000},"postexpandincludesize":{"value":153086,"limit":2097152},"templateargumentsize":{"value":11637,"limit":2097152},"expansiondepth":{"value":14,"limit":40},"expensivefunctioncount":{"value":9,"limit":500},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 746.082 1 -total"," 32.40% 241.765 1 Template:Reflist"," 23.68% 176.705 1 Template:Korean"," 22.77% 169.911 1 Template:Lang"," 12.87% 96.009 18 Template:Cite_journal"," 9.85% 73.487 7 Template:Cite_book"," 8.86% 66.110 5 Template:Fix"," 8.05% 60.054 4 Template:Ambox"," 7.29% 54.387 1 Template:Multiple_issues"," 6.08% 45.399 2 Template:Which"]},"scribunto":{"limitreport-timeusage":{"value":"0.433","limit":"10.000"},"limitreport-memusage":{"value":15977929,"limit":52428800}},"cachereport":{"origin":"mw1268","timestamp":"20180116141510","ttl":1900800,"transientcontent":false}}});});(window.RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgBackendResponseTime":980,"wgHostname":"mw1268"});});


Pollen - Photos and All Basic Informations

Pollen More Links

Pollen (disambiguation)ExeneEnlargeAntherEnlargeEnlargeScanning Electron MicroscopeHelianthus AnnuusIpomoea PurpureaSidalcea MalvifloraLilium AuratumOenothera FruticosaRicinus CommunisGametophyteSpermatophytaGameteSporopolleninStamenGynoeciumConifer ConePinophytaGerminatePollen TubeSpermOvulePalynologyPaleoecologyPaleontologyArchaeologyForensic ScienceStamenEnlargeOenothera SpeciosaEnlargeLilium AuratumEnlargeArabisEnlargeLycopersicon EsculentumEnlargePollen TubeMicrosporangiaFlowering PlantFlowerElectron MicrographPineFirSpruceForget-me-notWikipedia:Avoid Weasel WordsMicrometreWikipedia:Citation NeededMicrosporeMeiocyteMeiotic DivisionCytokinesisMonocotsMicrogametophyteWikipedia:Avoid Weasel WordsGerminationCelluloseSporopolleninSulcus (morphology)EudicotsTricolpatePollinationEnlargeApis MelliferaPollen BasketEnlargeEpisyrphus BalteatusCistusEnlargeDiadasiaCarpelsOpuntia EngelmanniiCactusCarpelPollinationAnemophilyEntomophilyProteinInsectPollinatorMitePalynivoreOvuleNucellusPinophytaGnetophytaFlagellaCycadGinkgophytaCarpelOvary (plants)PlacentaOvulePollen TubeDNA RepairGenomeDNA RepairPalynologyDevonianWikipedia:VerifiabilityAllergy SeasonTalk:PollenHelp:Maintenance Template RemovalWikipedia:WikiProject Countering Systemic BiasTalk:PollenWikipedia:Article WizardHelp:Maintenance Template RemovalWikipedia:VerifiabilityHelp:Introduction To Referencing With Wiki Markup/1Help:Maintenance Template RemovalHelp:Maintenance Template RemovalAllergic RhinitisPollinosisHay FeverGoldenrodRagweedArizonaIrrigationOakBirchHickoryPecanGrassAllergic ResponseHereditary DiseaseEczemaAsthmaDenmarkGeneral PractitionerAllergic RhinitisAntihistaminesLoratadineCetirizineChlorpheniramineHistamineBiogenic AmineDecongestantsNasal SprayAllergen ImmunotherapyPredatoryParasiticArthropodBeeHymenopteraLarvaAntSpiderCarnivoreSpiderSpider WebWikipedia:Citation NeededAcariEuseius TularensisMordellidaeMelyridaeCurculionidaeChrysomelidaeCerambycidaeScarabaeidaeCarabidaeLadybirdHemipteraHerbivoreOmnivoreAnthocoridaeSyrphidaeFlyFomes FomentariusDetritivoreHeliconiusBatButterflyHummingbirdPer Se (terminology)NectarPollinationBee PollenFoodDietary SupplementCarbohydrateHoneyP-coumaric AcidU.S. Food And Drug AdministrationForensic PalynologyEnlargeScanning Electron MicroscopeCercisForensic BiologyBosniaHypericumEuropean Pollen DatabaseEvolution Of SexMicrosporangiaPollen CalendarPollen CountPollen SourcePolyphenol AntioxidantPalynologyInternational Standard Book NumberSpecial:BookSources/0-19-914766-3Digital Object IdentifierPubMed CentralPubMed IdentifierPaula RudallDigital Object IdentifierDigital Object IdentifierPubMed IdentifierPaula RudallDigital Object IdentifierDigital Object IdentifierInternational Standard Book NumberSpecial:BookSources/978-0-08-051404-8International Standard Book NumberSpecial:BookSources/9781578083510Digital Object IdentifierPubMed IdentifierDigital Object IdentifierPubMed CentralPubMed IdentifierPubMed IdentifierDanish Meteorological InstituteDigital Object IdentifierInternational Standard Book NumberSpecial:BookSources/978-1-4020-9234-3Springer Science+Business MediaInternational Standard Book NumberSpecial:BookSources/978-3-540-67205-0Category:CS1 Maint: Multiple Names: Authors ListDigital Object IdentifierDigital Object IdentifierPubMed IdentifierDigital Object IdentifierPubMed CentralPubMed IdentifierCategory:CS1 Maint: Multiple Names: Authors ListDigital Object IdentifierDigital Object IdentifierPubMed CentralPubMed IdentifierDigital Object IdentifierPubMed CentralPubMed IdentifierDigital Object IdentifierDigital Object IdentifierPubMed IdentifierDigital Object IdentifierPubMed IdentifierDigital Object IdentifierInternational Standard Book NumberSpecial:BookSources/0-08-051404-9International Standard Book NumberSpecial:BookSources/1-57808-351-6Public DomainEncyclopædia Britannica Eleventh EditionTemplate:BotanyTemplate Talk:BotanyBotanyHistory Of BotanyBranches Of BotanyHistory Of Plant SystematicsEthnobotanyPaleobotanyPlant AnatomyPlant EcologyPhytogeographyGeobotanical ProspectingFloraPhytochemistryPlant PathologyBryologyPhycologyFloristicsDendrologyPlantAlgaeArchaeplastidaBryophyteNon-vascular PlantVascular PlantSpermatophytePteridophyteGymnospermFlowering PlantPlant MorphologyGlossary Of Plant MorphologyPlant CellCell WallPhragmoplastPlastidPlasmodesmaVacuoleTissue (biology)MeristemVascular TissueVascular BundleGround TissueLeafCork CambiumWoodStorage OrganRootRhizoidBulbRhizomeShootPlant StemLeafPetiole (botany)CataphyllBudSessility (botany)Plant Reproductive MorphologyABC Model Of Flower DevelopmentInflorescenceUmbelRacemeBractPedicel (botany)FlowerWhorl (botany)Floral SymmetryFloral DiagramFloral FormulaReceptacle (botany)HypanthiumPerianthTepalPetalSepalSporophyllGynoeciumOvary (botany)OvuleStigma (botany)ArchegoniumStamenStamenStaminodeTapetum (botany)Column (botany)GametophyteSporophyteEmbryoFruitFruit AnatomyBerry (botany)Capsule (fruit)SeedSeed DispersalEndospermEpicuticular WaxPlant CuticleEpidermis (botany)StomaNectarTrichomeThorns, Spines, And PricklesPlant PhysiologyPlant NutritionPhotosynthesisChlorophyllPlant HormoneTranspirationTurgor PressureBulk MovementAleuronePhytomelaninSugarSapStarchCelluloseSecondary GrowthWoody PlantHerbaceous PlantHabit (biology)VineLianaShrubSubshrubTreeSucculent PlantPlant ReproductionPlant EvolutionPlant EcologyAlternation Of GenerationsSporangiumSporeMicrosporangiaMicrosporeSporangiumMegasporePollinationPollinatorPollen TubeDouble FertilizationGerminationPlant Evolutionary Developmental BiologyEvolutionary History Of PlantsTimeline Of Plant EvolutionHardiness ZonePlant TaxonomyHistory Of Plant SystematicsHerbariumTaxonomy (biology)Botanical NomenclatureBotanical NameCorrect NameAuthor Citation (botany)International Code Of Nomenclature For Algae, Fungi, And PlantsInternational Code Of Nomenclature For Cultivated PlantsTaxonomic RankInternational Association For Plant TaxonomyList Of Systems Of Plant TaxonomyCultivated Plant TaxonomyCitrus TaxonomyCultigenCultivarCultivar GroupGrex (horticulture)AgronomyFloricultureForestryHorticultureGlossary Of Botanical TermsList Of BotanistsList Of Botanists By Author Abbreviation (W–Z)Botanical ExpeditionCategory:BotanyPortal:PlantsWikipedia:WikiProject PlantsHelp:Authority ControlIntegrated Authority FileNational Diet LibraryHelp:CategoryCategory:Plant AnatomyCategory:Plant MorphologyCategory:PalynologyCategory:PollinationCategory:AllergologyCategory:CS1 Maint: Multiple Names: Authors ListCategory:All Articles With Specifically Marked Weasel-worded PhrasesCategory:Articles With Specifically Marked Weasel-worded Phrases From February 2017Category:All Articles With Unsourced StatementsCategory:Articles With Unsourced Statements From February 2017Category:All Pages Needing Factual VerificationCategory:Wikipedia Articles Needing Factual Verification From July 2007Category:Articles With Limited Geographic Scope From September 2010Category:USA-centricCategory:Articles Needing Additional References From March 2013Category:All Articles Needing Additional ReferencesCategory:Articles To Be Expanded From March 2013Category:All Articles To Be ExpandedCategory:Articles Using Small Message BoxesCategory:Articles With Multiple Maintenance IssuesCategory:Articles With Unsourced Statements From April 2012Category:Articles Containing Korean-language TextCategory:Wikipedia Articles Incorporating A Citation From The 1911 Encyclopaedia Britannica With No Article ParameterCategory:Wikipedia Articles Incorporating Text From The 1911 Encyclopædia BritannicaCategory:Wikipedia Articles With GND IdentifiersDiscussion About Edits From This IP Address [n]A List Of Edits Made From This IP Address [y]View The Content Page [c]Discussion About The Content Page [t]Edit This Page [e]Visit The Main Page [z]Guides To Browsing WikipediaFeatured Content – The Best Of WikipediaFind Background Information On Current EventsLoad A Random Article [x]Guidance On How To Use And Edit WikipediaFind Out About WikipediaAbout The Project, What You Can Do, Where To Find ThingsA List Of Recent Changes In The Wiki [r]List Of All English Wikipedia Pages Containing Links To This Page [j]Recent Changes In Pages Linked From This Page [k]Upload Files [u]A List Of All Special Pages [q]Wikipedia:AboutWikipedia:General Disclaimer



view link view link view link view link view link