Gall 217384 225875783 2008-07-15T20:32:34Z Filll 2379776 wl [[Image:Crown-gall.jpg|thumb|right|250px|[[Kalanchoe|Kalanchoë]] infected with crown gall using ''[[Agrobacterium tumefaciens]]''.]] [[Image:Crown-gall_detail.jpg|thumb|right|250px|A detail photo of a crown gall on a [[Kalanchoë]] infected with ''[[Agrobacterium tumefaciens]]''.]] {{otheruses}} '''Galls''' or plant galls are abnormal outgrowths<ref> [[http://www.m-w.com/dictionary]] Merriam-Webster Online Dictionary, accessed Nov. 16, 2007 (''"an abnormal outgrowth of plant tissue usually due to insect or mite parasites or fungi and sometimes forming an important source of tannin"'')</ref> of [[plant]] tissues and can be caused by various [[parasite]]s, from [[fungi]] and [[bacterium|bacteria]], to [[insect]]s and [[mite]]s. Galls are often very organised structures and because of this, the cause of the gall can often be determined without the actual agent being identified. This applies particularly to some insect and mite galls. ==Causes of plant galls== ===Insects=== '''Insect galls''' develop under the influence of [[gall-inducing insect]]s. Insect galls are usually induced by the chemicals injected by the [[larva]]e or the [[adult]]s in the plants, either including mechanical damage or not. After the galls are formed, the larvae develop inside until fully grown, at which time they leave, sometimes as adults. In order to form galls, the insects must seize the time when plant cell division occurs at a high speed, the growing season, usually spring in temperate climates, but which can be extended in tropical latitudes. Also, the specific places where plant cell division occurs are needed to induce galls, that is, the [[meristem]]s. Although insect galls can be found on a variety of parts of the plant, such as the leaves, [[stalk (botany)|stalk]]s, [[branch]]es, [[bud]]s, [[root]]s or even [[flower]]s and [[fruit]]s, gall-inducing insects are usually species-specific and sometimes tissue-specific on the plants they gall. Some insects induce galls on plants similar to each other, frequently within genera or family. [[Gall-inducing insect]]s include [[gall wasp]]s, [[gall midge]]s, [[aphid]]s, and [[psyllid]]s. ===Fungi=== A gall-inducing fungus is: [[Gymnosporangium|Cedar-apple rust]] ===Bacteria and viruses=== [[Agrobacterium tumefaciens | Crown Gall]] is an example of a gall-causing bacterium. ===Other Plants=== [[Mistletoe]] can form galls on its hosts == Uses == Galls are rich in resins and [[tannic acid]] and have been used in the manufacture of permanent inks (such as [[iron gall ink]]) and astringent ointments, in [[dyeing]], and in [[tanning]]. A high-quality ink has long been made from the Aleppo gall, found on oaks in the Middle East; it is one of a number of galls resembling nuts and called "gallnuts" or "nutgalls'. The larvae in galls is useful for a survival food and fishing bait. ==Gallery== <gallery> Image:Maple_leaf_gall.jpg|<center>Gall on a [[Maple]] leaf Image:Diplolepis-rosae.jpg|<center>Rose bedeguar gall on a [[wild rose]] in summer. Image:Diplolepis Quercus01.jpg|<center>Andricus fecundator Image:Gallwespe bedient sich Eichel2.jpg|<center>Andricus quercuscalicis Image:Diplolepis Quercus02.jpg|<center>Andricus quercuscalicis image:Eikengallen op mannelijke bloeiwijze.jpg|<Center>''Neuroterus albipes'' forma ''laeviusculus'' Image:Eucalyptus gall.jpg|<center>[[Eucalyptus]] leaf gall Image:Oak Gall.jpg|<Center>''Andricus kollari'' oak gall Image:Cedar apple rust telial form.JPG|[[Gymnosporangium]] Image:Oak marble galls 1.JPG|<Center>[[Oak]] marble galls, one with a Gall fly exit hole and another with ''Phoma gallorum'' fungal attack. Image:Oak marble gall sectioned.JPG|<Center>Sectioned gall showing central 'cell' and inquiline chamber; exit-hole and a possibly parasitised stunted gall specimen. Image:Pineapple gall.JPG|[[Pineapple gall]] on [[Sitka Spruce]] caused by Adelges abietis. Image:Developing Pineapple Gall.JPG|Developing Pineapple pseudocone galls on [[Norway Spruce]] </gallery> == Footnotes == {{reflist}} == See also == * [[Bush coconut]] *[[Mulga apple]] *[[Oak apple]] *[[Oak Marble gall]] *[[Knopper gall]] *[[Oak artichoke gall]] *[[Rose bedeguar gall]] == Online references == * {{cite web | title=Gall | work=Infoplease encyclopedia | url=http://www.infoplease.com/ce6/sci/A0820047.html | accessmonthday = March| accessyear=2006}} * {{cite web | title=Common oak gall | work=University of Kentucky Entomology | url=http://www.uky.edu/Ag/Entomology/entfacts/trees/ef408.htm | accessmonthday = September 11| accessyear=2006}} [[Category:Plant pathogens and diseases]] [[ca:Agalla (botànica)]] [[cs:Hálka]] [[da:Galle]] [[de:Gallapfel]] [[es:Agalla]] [[eo:Gajlo]] [[fr:Galle (botanique)]] [[gl:Bugallo]] [[it:Galla (botanica)]] [[he:עפץ]] [[lt:Galas]] [[nl:Galappel]] [[ja:虫こぶ]] [[pl:Galas]] [[pt:Galha]] [[zh:癭]]