Duillag
{{ymmydynelley|organe lossreeyn|duillag (reddaghey)}}
[[Coadan:Leavessnipedale.jpg|thumb|right|200px|Duillagyn [[faih]]]]
Ayns [[lus-oaylleeaght]], she [[organe (ronsaghey-kirpey)|organe]] [[lus|lossreeyn]] ta currit da [[co-haaghey sollysh]] eh '''duillag'''.  Er son shen, ta duillagyn lhean as keyl son y chooid smoo.  Ta'n lheanid shoh cur y duillag fo ny smoo soilshey as [[daa-ocseed charboan]], agh t'eh coayl ny smoo ushtey na cummey cruinn.  Rish yn [[Eash Devonagh]], tra va co-chruinnaghey daa-ocseed charboan ymmodee keayrtyn ny smoo ta jiu, cha row duillagyn ny [[gass|gish]] reaey ec lossreeyn.  Ta oltyn rea lheaney ta co-haaghey sollysh ec ymmodee [[bryophyta|bryophyteyn]], agh cha nee feer duillag t'ayn.  Shen feer bentyn rish [[microphyll]]yn [[lycophyta|lycophyteyn]] myrgeddin.  T'ad cur [[macrophyll]], [[megaphyll]] as [[euphyll]] er duillagyn [[renniagh|renniee]], [[gymnosperm]]yn as [[angiosperm]]yn ny keayrtyn.

Ta [[trooid-ghaalaghey]] as [[bineal]] taghyrt ayns duillagyn, dy cadjin.  T'ad tashtey [[bee]] as [[ushtey]], as ta kuse jeu er nyn gaghlaa er son obbraghyn elley.  

Ta duillagyn scanshoil myr bee beiyn as deiney.

== Strughtoor ==
[[Coadan:Bifacial leaf cross section.jpg|thumb|right|Caslys giarrey tessen jeh duillag]]

Ta lane duillag [[angiosperm]]agh jeant magh jeh [[cass duillag]] (gass y duillag), [[lhiann]] (y "duillag" hene) as [[stipule]]yn (reddyn ta gaase ec çheughyn y chass duillag).  Cha nel y tree jeu ec dagh dooie dy lus.  Myr sampleyr, foddee nagh vel stipuleyn ayn; cha nel cass duillag ec dagh dooie; as cha nel duillagyn dagh dooie lhiannagh (jeant rea).

She [[olt lossreeyn]] eh duillag, as t'ad rheynn ad ayns tree [[stoo kirp|stooghyn kirpey]]:

# [[Duillag#Epiderm|Epiderm]] ta coodaghey ny h-eaghtyryn
# [[Duillag#Mesophyll|Mesophyll]] çheusthie
# [[Duillag#Cuishlin duillag|Cuishlinyn duillag]]

[[Coadan:Leaf anatomy numberated.svg|thumb|center|600px|Diagram strughtooragh jeh duillag.
<br />1. [[Craaish lossreeyn|Craaish]]
<br />2. [[Epiderm]] s'ardjey
<br />3. [[Mesophyll çhionn]]
<br />4. [[Mesophyll thoagagh]]
<br />5. [[Epiderm]] s'inshley
<br />6. [[Stoma]]
<br />7. [[Killag skaa|Killagyn skaa]]
<br />8. [[Sylem]]
<br />9. [[Phloem]]
<br />10. [[Dhossan cuishlagh]]
]]

=== Epiderm ===
[[Coadan:Leaf epidermis 2.jpg|thumb|right|Killagyn epidermagh]]
She coodagh dy [[killag|chillagyn]] eh yn [[epiderm (lus-oaylleeaght)|epiderm]].  T'eh geddyr-scarrey killagyn ny lus jeh'n teihll.  T'eh coadey noi coayl ushtey liorish [[trooid-ghaalaghey]], as stiurey [[co-cheaghley gas]], taaley covestaghyn soe, as ny keayrtyn, maanalys ushtey.  Ta strughtoor [[termeeaght chorpronsagh|drommey-tarragh]] echey son y chooid smoo; dy ghra myr shen, cha nel yn eaghtyr s'ardjey gollrish yn eaghtyr s'inshley, as foddee obbraghyn er lheh ve oc.

Ta'n epiderm [[tarhoilshaght|tarhoilshagh]] dy mennick (cha nel [[chloroplast]]yn ec killagyn epidermagh), as ta [[craaish lossreeyn|craaish]] kereagh ta lhiettal coayl ushtey.  Ta craaish ny s'çhee ec duillagyn lossreeyn ass çhymbyllaghtyn çhirrym na ec adsyn ass çhymbyllaghtyn fliugh.

[[Coadan:Leaf epidermis w scale.jpg|thumb|left|Caslys [[Mynreayrtan lectrane scaney|MLS]] jeh epiderm duillag ''[[Nicotiana alata]]''.  Ta [[trichome|trichromeyn]] (gollrish jialg) as [[stoma]]ta (scoltaghyn sooillagh, ry-akin ec cruinnys myn) ry-akin.]]

Ta stoo kirpey epiderm goaill stiagh ymmodee sorçhyn dy chillag er lheh: killagyn epidermagh, killagyn skaa, killagyn coonee as trichomeyn (renaigyn epidermagh).  She killagyn epidermagh ad y chooid smoo jeu, as adsyn y chooid smoo bunneydagh.

Ta dorallyn ([[stoma]]ta) ayns yn epiderm.  T'ad jeant magh jeh doral as killagyn skaa mygeayrt echey.  Ta chloroplastyn ayns ny killagyn skaa.  Ta daa dys kiare killagyn coonee gyn chloroplastyn mygeayrt oc.  Dy cadjin, ta ny smoo stomata 'syn epiderm s'inshley na'n epiderm s'ardjey.

Ta'n chooid smoo jeh'n duillag eddyr yn epiderm jeant magh jeh stoo kirpey ''[[parenchyma]]'' ny ''[[chlorenchyma]]''.  T'ad cur "mesophyll" er ("mean duillag" 'sy [[Greagish|Ghreagish]]).  Shoh ynnyd smoo scanshoil 'sy lus dysf [[co-haaghey sollysh]].  She stoo kirpey [[cosoylaghey (bea-oaylleeaght)|cosoylaghey]] t'ayn; t'eh lheie stooghyn kemmigagh as jannoo soo kirpey jeu.

=== Mesophyll ===
[[Coadan:Leaf palisade mesophyll.jpg|thumb|right|Killagyn mesophyll çhionn]]

Ta mesophyll [[renniagh|renniee]] as [[angiosperm]]yn er ny rheynn ayns daa vrat:

* Brat s'ardjey dy [[mesophyll çhionn|chillagyn mesophyll çhionn]].  T'ad sheeynit dy jeeragh seose, rollianagh, as çhionn rish y cheilley.  Ta'n brat shoh dy jeeragh fo yn epiderm s'inshley.  Ta ram [[chloroplast]]yn ayn, as ad faggys da boallaghyn ny killag.  T'ad reaghit ayns un dys queig straihyn.  Ta'n oardagh shoh mooadaghey maanalys [[daa-ocseed charboan]], as jannoo share jeh soilshey ny greiney.  Er y fa nagh vel agh scarrey beg eddyr ny killagyn, foddee [[myn-eddanaght]] ymmyrkey ushtey eddyr oc.  Ta mesophyll çhionn yl-vrattagh ec duillagyn lossreeyn ta currit da soilshey, as un vrat ec duillagyn lossreeyn ta currit da scaa.

[[Coadan:Leaf spongy mesophyll.jpg|thumb|right|Killagyn mesophyll thoanagh]]
* Brat s'inshley dy [[mesophyll thoanagh|chillagyn mesophyll thoanagh]].  Ta ny killagyn shoh ny s'cruinney as cha nel ad cho çhionn.  Ta reamyssyn mooarey aer eddyr-chillagagh.  Ta ny sloo chloroplastyn oc na ec killagyn çhionn.

Ta ny stomata fosley dys ny reamyssyn shoh.

Cha nel y daa vrat shoh ec dagh lus ushtagh.  Ny keayrtyn, nagh vel eer epiderm ny mesophyll oc.  T'adsyn jannoo ymmyd jeu '''[[aerenchyma]]''' co-cheintyssagh: killagyn as boallaghyn keylley oc, as reamyssyn mooar gassagh eddyr oc.  Ta ny stomata oc er yn eaghtyr s'ardjey.

=== Cuishlinyn ===
[[Coadan:Vein sceleton hydrangea ies.jpg|thumb|right|Ushylagh cuishlin dy ghuillag [[Hydrangea]]]]
Ta ny cuishlinyn nyn soie 'sy vesophyll thoanagh.  T'ad jeant magh jeh:

* [[Sylem]]: feddanyn ta gymmyrkey ushtey as stoo meainagh jeh ny fraueyn dys y duillag.
* [[Phloem]]: feddanyn ta gymmyrkey [[sapp]] ass y duillag, as [[sucrose]] ass [[co-haaghey sollysh]] lheieit ayn.

== Jalloo-oaylleeaght ==
=== Oardagh er y ghass ===
[[Coadan:Leaves opposite.jpg|thumb|right|Ta ny duillagyn shoh er nyn reaghey dy piyral, as dagh piyr kern-uillinagh rish y nah phiyr ("croshagh").  Ta buinnaghyn aegey ry-akin 'syn [[aghlish (lus-oaylleeaght)|aghlish]] raad ta'n chass duillag kianglt rish y ghass.]]
* '''Maylartey''' — ta un duillag kianglt rish dagh noad, as ta ny duillagyn maylartey er y daa heu harrish y ghass.
* '''Piyral''' — ta daa ghuillag kianglt rish adgh noad; t'ad ''[[croshagh]]'' my ta dagh piyr çhyndaait rere y phiyr roish; t'ad ''jeeragh'' my t'ad gaase ayns daa straih er yn un phlaaney.
* '''Fainagh''' — ta tree ny ny smoo kianglt rish dagh noad er y ghass.  Ny keayrtyn, ta'n 'ainey croshagh rere yn 'ainey roish.
* '''Roseagh''' — ta ny duillagyn ayns cummey [[cront (lus-oaylleaght)|cront]].

Lesh aase ny gass, ta duillagyn reaghey ad hene mygeayrt y ghass er son dy hareaghey ymmyd sollys.  T'ad jannoo [[shlig chassee]] mygeayrt y ghass.  Ta uillin ny duillagyn rere [[straih Fibonacci]]: 1/2, 2/3, 3/5, 5/8, 8/13, 13/21, 21/34, 34/55, 55/89. 'sy straih shoh, ta'n [[earrooder]] cowraghey yn earroo dy lane hymshal mygeayrt y ghass derrey vees duillag 'syn ynnyd toshee reesht.  Ta'n [[enmysser]] cowraghey quoid dy ghuillagyn t'ayn.  Myr shen:

* ta duillagyn maylartey er uillin 180° (myr shen, 1/2 kiarkyl, hoal noi y cheilley)
* 120° (1/3) : tree duillagyn ayns çhymshal
* 144° (2/5) : queig duillagyn ayns daa hymshal
* 135° (3/8) : hoght duillagyn ayns tree çhymshallyn

=== Ayrnyn y lhiann ===
{{ardart|cummey duillag}}

Ta daa horçh dy ghuillag ry-hoilshaghey bentyn rish rheynn y duillag.  Ta lhiann neurheynnit ec '''duillag bunneydagh'''.  Ny keayrtyn, ta cummey y duillag jeant jeh babbanyn, agh cha nel ny baarnaghyn eddyr oc roshtyn yn ard-chuishlin.  Ta lhiann rheynnit ec '''yl-ghuillag''', as dagh [[duillageen]] echey rheynnit er ard-chuishlin ny fo-chuishlin.  Ny keayrtyn, t'eh jeeaghyn dy vel dagh duillageen ny ghuillag hene.  Myr shen, she scanshoil eh dy chur tastey er raad ta'n cass duillag, dys cur enney er yl-ghuillag.  T'ad cowreydagh jeh shiartanse dy chynneeyn er lheh, myr sampleyr, [[Fabaceae]].  T'ad cur [[rachis]] er cuishlin veanagh y duillag.

=== Troyn y chass duillag ===
[[Coadan:Rabarber stelen.jpg|thumb|right|200px|Ta cassyn duillag ro-vooarey [[rhubarb]] (''Rheum rhabarbarum'') yn-ee.]]

Ta duillagyn as cass oc ayn, as duillagyn gyn cass myrgeddin.  Adsyn gyn cass, ta'n lhiann kianglt dy jeeragh rish y ghass. Foddee y lhiann goll mygeayrt y ghass, as ny keayrtyn, t'eh jeeaghyn dy vel y ghass gaase ny trooid.  Shen feer ec kuse jeu, as t'ad cur [[cummey duillag#thiollit|thiollit]] (ny ''perfoliata'') orroosyn, m.s. ''[[Claytonia perfoliata]]''.

Ec duillagyn ''peltata'', ta'n cass duillag kianglt rish eaghtyr y lhiann, cha nel rish yn oirr echey.

Ta cass duillag lheanit ec shiartase dy ghooieyn ''[[Acacia]]'', as t'ad jannoo obbyr lhiann.  T'ad cur ''[[phyllode]]yn'' orroo.  Ny keayrtyn, ta duillag cadjin fedjagagh ec birr y phyllode.

Ta [[stipule]], ry-akin ec ymmodee [[dicotyledon]]yn.  She famman gollrish duillag beg t'ayn, as t'ad nyn soie ec çheuyn y chass duillag.  Ta fir foddey beayn ayn nagh vel tuittym (m.s. ayns [[rose]]yn as [[poanrey|poanraghyn]]), agh ta fir elley tuittym.

=== Oardagh ny cuishlinyn ===
{{ardart|cummey duillag}}

[[Coadan:Taro leaf underside, backlit by sun.jpg|thumb|200px|Cuishlinyn banglaneagh er çheu heese duillag [[taro]].]]

Ta ram termeeaght er lheh bentyn rish cuishlinaght duillagyn.

Ta un aarheynn bentyn rish lheanid ny cuishlinyn:
* ''craspedodromous'' (ard-chuishlinyn roshtyn oirr y duillag) 
* ''camptodromous'' (cha nel ard-chuishlinyn roshtyn oirr y duillag).

Son y chooid smoo, t'ad aarheynn duillagyn er bun cummey ny banglaneaght ny cuishlinyn.

<!--
===Morphology changes within a single plant===
* Homoblasty - Characteristic in which a plant has small changes in leaf size, shape, and growth habit between juvenile and adult stages.
* Heteroblasty - Characteristic in which a plant has marked changes in leaf size, shape, and growth habit between juvenile and adult stages. 
<br clear=right>

== Terminology ==
[[File:Leaf morphology.svg|thumb|300px|Chart illustrating some leaf morphology terms]]
[[Image:Celery Leaf.JPG|thumb|A portion of a [[celery]] leaf]]
===Shape===
{{main|Leaf shape}}

=== Margins (edge) ===
The leaf margin is characteristic for a genus and aids in determining the species.
* '''''ciliate:'''''  fringed with hairs
* '''''crenate:'''''  wavy-toothed; dentate with rounded teeth, such as [[beech|''Fagus'']] (beech)
* '''''crenulate''''' finely or shallowly crenate
* '''''dentate:'''''  toothed, such as [[Chestnut|''Castanea'']] (chestnut)
** '''''coarse-toothed:'''''  with large teeth
** '''''glandular toothed:'''''  with teeth that bear glands.
* '''''denticulate:'''''  finely toothed
* '''''doubly toothed:'''''  each tooth bearing smaller teeth, such as [[elm|''Ulmus'']] (elm)
* '''''entire:'''''  even; with a smooth margin; without toothing
* '''''lobate:'''''  indented, with the indentations not reaching to the center, such as many [[Oak|''Quercus'']] (oaks)
** '''''palmately lobed:'''''  indented with the indentations reaching to the center, such as [[Hop (plant)|''Humulus'']] (hop).
* '''''serrate:'''''  saw-toothed with asymmetrical teeth pointing forward, such as [[Nettle|''Urtica'']] (nettle)
* '''''serrulate:'''''  finely serrate
* '''''sinuate:'''''  with deep, wave-like indentations; coarsely crenate, such as many ''[[Rumex]]'' (docks)
* '''''spiny:'''''  with stiff, sharp points, such as some [[holly|''Ilex'']] (hollies) and [[thistle|''Cirsium'']] (thistles).

=== Tip of the leaf ===
[[Image:Leaves-scan.jpg|thumb|right|200px|Leaves showing various morphologies. Clockwise from upper left: tripartite lobation, elliptic with serrulate margin, peltate with palmate venation, acuminate odd-pinnate (center), pinnatisect, lobed, elliptic with entire margin]]

* '''''acuminate:'''''  long-pointed, prolonged into a narrow, tapering point in a concave manner.
* '''''acute:'''''  ending in a sharp, but not prolonged point
* '''''cuspidate:'''''  with a sharp, elongated, rigid tip; tipped with a cusp.
* '''''emarginate:'''''  indented, with a shallow notch at the tip.
* '''''mucronate:'''''  abruptly tipped with a small short point, as a continuation of the midrib; tipped with a mucro.
* '''''mucronulate:'''''  mucronate, but with a smaller spine.
* '''''obcordate:'''''  inversely heart-shaped, deeply notched at the top.
* '''''obtuse:'''''  rounded or blunt
* '''''truncate:'''''  ending abruptly with a flat end, that looks cut off.

=== Base of the leaf ===
* '''''acuminate:'''''  coming to a sharp, narrow, prolonged point.
* '''''acute:'''''  coming to a sharp, but not prolonged point.
* '''''auriculate:'''''  ear-shaped.
* '''''cordate:'''''  heart-shaped with the notch towards the stalk.
* '''''cuneate:'''''  wedge-shaped.
* '''''hastate:'''''  shaped like an halberd and with the basal lobes pointing outward.
* '''''oblique:'''''  slanting.
* '''''reniform:'''''  kidney-shaped but rounder and broader than long.
* '''''rounded:'''''  curving shape.
* '''''sagittate:'''''  shaped like an arrowhead and with the acute basal lobes pointing downward.
* '''''truncate:'''''  ending abruptly with a flat end, that looks cut off.

=== Surface of the leaf ===
[[Image:Norfolk Pine 1758c.jpg|thumb|right|200px|Scale-shaped leaves of a Norfolk Island Pine, ''[[Araucaria heterophylla]]''.]]

The surface of a leaf can be described by several botanical terms:
* '''''farinose:'''''  bearing farina; mealy, covered with a waxy, whitish powder.
* '''''glabrous:'''''  smooth, not hairy.
* '''''[[glaucous]]:'''''  with a whitish bloom; covered with a very fine, bluish-white powder.
* '''''glutinous:'''''  sticky, viscid.
* '''''papillate''''', or '''''papillose:'''''  bearing papillae (minute, nipple-shaped protuberances).
* '''''pubescent:'''''  covered with erect hairs (especially soft and short ones).
* '''''punctate:'''''  marked with dots; dotted with depressions or with translucent glands or colored dots.
* '''''rugose:'''''  deeply wrinkled; with veins clearly visible.
* '''''scurfy:'''''  covered with tiny, broad scalelike particles. 
* '''''tuberculate:'''''  covered with tubercles; covered with warty prominences.
* '''''verrucose:'''''  warted, with warty outgrowths.
* '''''viscid''''', or '''''viscous:'''''  covered with thick, sticky secretions.

The leaf surface is also host to a large variety of [[microorganisms]]; in this context it is referred to as the [[phyllosphere]].

[[Image:Tulip Leaves AWL.JPG|thumb|right|200px|The parallel veins within an [[Iris (plant)|iris]] leaf.]]

=== Hairiness (trichomes) ===
[[Image:Starr 040723-0032 Verbascum thapsus.jpg|thumb|right|200px|Common Mullein (''[[Verbascum thapsus]]'') leaves are covered in dense, stellate trichomes.]]
[[Image:Coleus leaf trichomes SEM.jpg|thumb|right|200px|Scanning electron microscope image of trichomes on the lower surface of a ''Coleus blumei'' ([[coleus]]) leaf.]]

"Hairs" on plants are properly called [[trichome]]s. Leaves can show several degrees of hairiness. The meaning of several of the following terms can overlap.
* '''''arachnoid''''', or '''''arachnose:'''''  with many fine, entangled hairs giving a cobwebby appearance.
* '''''barbellate:'''''  with finely barbed hairs (barbellae).
* '''''bearded:'''''  with long, stiff hairs.
* '''''bristly:'''''  with stiff hair-like prickles.
* '''''canescent:''''' hoary with dense grayish-white pubescence.
* '''''ciliate:'''''  marginally fringed with short hairs (cilia).
* '''''ciliolate:'''''  minutely ciliate.
* '''''floccose:'''''  with flocks of soft, woolly hairs, which tend to rub off.
* '''''glabrous:'''''  no hairs of any kind present.
* '''''glandular:'''''  with a gland at the tip of the hair.
* '''''hirsute:'''''  with rather rough or stiff hairs.
* '''''hispid:'''''  with rigid, bristly hairs.
* '''''hispidulous:'''''  minutely hispid.
* '''''hoary:'''''  with a fine, close grayish-white pubescence.
* '''''lanate''''', or '''''lanose:'''''  with woolly hairs.
* '''''pilose:'''''  with soft, clearly separated hairs.
* '''''puberulent''''', or '''''puberulous:'''''  with fine, minute hairs.
* '''''pubescent:'''''  with soft, short and erect hairs.
* '''''scabrous''''', or '''''scabrid:'''''  rough to the touch.
* '''''sericeous:'''''  silky appearance through fine, straight and appressed (lying close and flat) hairs.
* '''''silky:'''''  with adpressed, soft and straight pubescence.
* '''''stellate''''', or '''''stelliform:'''''  with star-shaped hairs.
* '''''strigose:'''''  with appressed, sharp, straight and stiff hairs.
* '''''tomentose:'''''  densely pubescent with matted, soft white woolly hairs.
** '''''cano-tomentose:'''''  between canescent and tomentose.
** '''''felted-tomentose:'''''  woolly and matted with curly hairs.
* '''''villous:'''''  with long and soft hairs, usually curved.
* '''''woolly:''''  with long, soft and tortuous or matted hairs.

==Adaptations==
{{Cleanup-laundry|date=February 2008}}
[[Image:Inflorescence 1.jpg|thumb|right|250px|[[Poinsettia]] [[bract]]s are leaves which have evolved red pigmentation in order to attract insects and birds to the central flowers, an adaptive function normally served by [[petal]]s (which are themselves leaves highly modified by evolution).]]

In the course of [[evolution]], leaves have adapted to different [[environment (biophysical)|environment]]s in the following ways:
* A certain surface structure avoids moistening by rain and contamination (''See [[Lotus effect]]'').
* Sliced leaves reduce wind resistance.
* Hairs on the leaf surface trap humidity in dry climates and create a large [[boundary layer]] thereby reducing water loss.
* [[Wax]]y leaf surfaces reduce water loss.
* Large surface area of leaf provides large area for sunlight and provides shade for plant to minimize heating and reduce water loss.
* In more or less opaque or buried in the soil leaves, translucent windows filter the light before the photosynthesis takes place at the inner leaf surfaces (e.g. ''[[Fenestraria]]'').
* [[Succulent]] leaves store water and organic acids for use in [[CAM photosynthesis]].
* [[Aromatic oil]]s, [[poisons]] or [[pheromones]] produced by leaf borne glands deter herbivores (e.g. [[eucalypts]]).
* Inclusions of crystalline minerals deter herbivores (e.g. [[silica]] in [[grass]]es.
* A transformation into [[petal]]s attracts pollinators.
* A transformation into [[Spine (botany)|spines]] protects the plants (''e.g.'' [[cacti]]).
* A transformation into insect traps helps feeding the plants ([[carnivorous plant]]s).
* A transformation into [[bulb]]s helps storing food and water (''e.g.'' [[onion]]s).
* A transformation into [[tendril]]s allows the plant to climb (''e.g.'' [[pea]]s).
* A transformation into [[bract]]s and [[pseudanthium|pseudanthia]] (''false flowers'') replaces normal flower structures if the true flowers are extremely reduced (''e.g.'' [[Spurge]]s).

==Interactions with other organisms==
[[File:Kallima inachus2.jpg|150px|thumb|Some [[insect|insects]] mimic leaves (''[[Kallima inachus]]'' 
shown)]]
[[File:Autumn girl.jpg|150px|thumb|A girl playing with leaves]]
Although not as nutritious as other organs such as fruit, leaves provide a food source for many organisms. Animals which eat leaves are known as [[folivore]]s. The leaf is one of the most vital parts of the plant, and plants have evolved protection against folivores such as [[tannin]]s, chemicals which hinder the digestion of proteins and have an unpleasant taste. 

Some animals have [[crypsis|cryptic]] adaptations to avoid their own predators.  For example, some caterpillars will create a small home in the leaf by folding it over themselves, while other herbivores and their prey [[mimicry|mimic]] the appearance of the leaf. Some insects, such as the [[katydid]], take this even further, moving from side to side much like a leaf does in the wind.

==Bibliography ==
* ''Leaves: The formation, charactistics and uses of hundred of leaves in all parts of the world'' by [[Ghillean Tolmie Prance]]. 324 photographic plates in black and white, and colour by Kjell B Sandved  256 pages<ref>Published by Thames and Hudson ([[London]]) with an ISBN 0 500 54104 3</ref>

==Footnotes==
{{reflist}}

==See also==
* [[Abscission]] (losing of leaves)
* [[Cladophyll]]
* [[Guttation]] (beads of fluid forming at leaf margins)
* [[Leaf area index]]
* [[Phylloclade]]
* [[Vernation]] (sprouting of leaves)
* [[Evolution of leaves]]
* [[Leaf protein concentrate]]

==External links==
{{commonscat|Leaves}}
{{wiktionary|leaf}}
*[http://www.ibiblio.org/botnet/glossary/b_i.html ''VASCULAR PLANT SYSTEMATICS'' Section B. General Characters and Character States:  Position and Arrangement]
* [http://www.scienceaid.co.uk/biology/plants/transpiration.html Science aid: Leaf] Leaf structure and transpiration resource for teens.
{{-}}
{{Botany}}
-->

== Imraaghyn ==
{{rolleyimraaghyn}}

[[Ronney:Co-haaghey sollysh]]
[[Ronney:Fyshoaylleeaght lossreeyn]]
[[Ronney:Jalloo-oaylleeaght lossreeyn]]
[[Ronney:Ronsaghey-kirpey lossreeyn]]
Ayns lus-oaylleeaght, she organe lossreeyn ta currit da co-haaghey sollysh eh duillag.  Er son shen, ta duillagyn lhean as keyl son y chooid smoo.  Ta'n lheanid shoh cur y duillag fo ny smoo soilshey as daa-ocseed charboan, agh t'eh coayl ny smoo ushtey na cummey cruinn.  Rish yn Eash Devonagh, tra va co-chruinnaghey daa-ocseed charboan ymmodee keayrtyn ny smoo ta jiu, cha row duillagyn ny gish reaey ec lossreeyn.  Ta oltyn rea lheaney ta co-haaghey sollysh ec ymmodee bryophyteyn, agh cha nee feer duillag t'ayn.  Shen feer bentyn rish microphyllyn lycophyteyn myrgeddin.  T'ad cur macrophyll, megaphyll as euphyll er duillagyn renniee, gymnospermyn as angiospermyn ny keayrtyn.

Ta trooid-ghaalaghey as bineal taghyrt ayns duillagyn, dy cadjin.  T'ad tashtey bee as ushtey, as ta kuse jeu er nyn gaghlaa er son obbraghyn elley.  

Ta duillagyn scanshoil myr bee beiyn as deiney.

 Strughtoor 
thumb|right|Caslys giarrey tessen jeh duillag

Ta lane duillag angiospermagh jeant magh jeh cass duillag (gass y duillag), lhiann (y "duillag" hene) as stipuleyn (reddyn ta gaase ec çheughyn y chass duillag).  Cha nel y tree jeu ec dagh dooie dy lus.  Myr sampleyr, foddee nagh vel stipuleyn ayn; cha nel cass duillag ec dagh dooie; as cha nel duillagyn dagh dooie lhiannagh (jeant rea).

She olt lossreeyn eh duillag, as t'ad rheynn ad ayns tree stooghyn kirpey:

 Epiderm ta coodaghey ny h-eaghtyryn
 Mesophyll çheusthie
 Cuishlinyn duillag

thumb|center|600px|Diagram strughtooragh jeh duillag.
1. Craaish
2. Epiderm s'ardjey
3. Mesophyll çhionn
4. Mesophyll thoagagh
5. Epiderm s'inshley
6. Stoma
7. Killagyn skaa
8. Sylem
9. Phloem
10. Dhossan cuishlagh

 Epiderm 
thumb|right|Killagyn epidermagh
She coodagh dy chillagyn eh yn epiderm.  T'eh geddyr-scarrey killagyn ny lus jeh'n teihll.  T'eh coadey noi coayl ushtey liorish trooid-ghaalaghey, as stiurey co-cheaghley gas, taaley covestaghyn soe, as ny keayrtyn, maanalys ushtey.  Ta strughtoor drommey-tarragh echey son y chooid smoo; dy ghra myr shen, cha nel yn eaghtyr s'ardjey gollrish yn eaghtyr s'inshley, as foddee obbraghyn er lheh ve oc.

Ta'n epiderm tarhoilshagh dy mennick (cha nel chloroplastyn ec killagyn epidermagh), as ta craaish kereagh ta lhiettal coayl ushtey.  Ta craaish ny s'çhee ec duillagyn lossreeyn ass çhymbyllaghtyn çhirrym na ec adsyn ass çhymbyllaghtyn fliugh.

thumb|left|Caslys MLS jeh epiderm duillag Nicotiana alata.  Ta trichromeyn (gollrish jialg) as stomata (scoltaghyn sooillagh, ry-akin ec cruinnys myn) ry-akin.

Ta stoo kirpey epiderm goaill stiagh ymmodee sorçhyn dy chillag er lheh: killagyn epidermagh, killagyn skaa, killagyn coonee as trichomeyn (renaigyn epidermagh).  She killagyn epidermagh ad y chooid smoo jeu, as adsyn y chooid smoo bunneydagh.

Ta dorallyn (stomata) ayns yn epiderm.  T'ad jeant magh jeh doral as killagyn skaa mygeayrt echey.  Ta chloroplastyn ayns ny killagyn skaa.  Ta daa dys kiare killagyn coonee gyn chloroplastyn mygeayrt oc.  Dy cadjin, ta ny smoo stomata 'syn epiderm s'inshley na'n epiderm s'ardjey.

Ta'n chooid smoo jeh'n duillag eddyr yn epiderm jeant magh jeh stoo kirpey parenchyma ny chlorenchyma.  T'ad cur "mesophyll" er ("mean duillag" 'sy Ghreagish).  Shoh ynnyd smoo scanshoil 'sy lus dysf co-haaghey sollysh.  She stoo kirpey cosoylaghey t'ayn; t'eh lheie stooghyn kemmigagh as jannoo soo kirpey jeu.

 Mesophyll 
thumb|right|Killagyn mesophyll çhionn

Ta mesophyll renniee as angiospermyn er ny rheynn ayns daa vrat:

 Brat s'ardjey dy chillagyn mesophyll çhionn.  T'ad sheeynit dy jeeragh seose, rollianagh, as çhionn rish y cheilley.  Ta'n brat shoh dy jeeragh fo yn epiderm s'inshley.  Ta ram chloroplastyn ayn, as ad faggys da boallaghyn ny killag.  T'ad reaghit ayns un dys queig straihyn.  Ta'n oardagh shoh mooadaghey maanalys daa-ocseed charboan, as jannoo share jeh soilshey ny greiney.  Er y fa nagh vel agh scarrey beg eddyr ny killagyn, foddee myn-eddanaght ymmyrkey ushtey eddyr oc.  Ta mesophyll çhionn yl-vrattagh ec duillagyn lossreeyn ta currit da soilshey, as un vrat ec duillagyn lossreeyn ta currit da scaa.

thumb|right|Killagyn mesophyll thoanagh
 Brat s'inshley dy chillagyn mesophyll thoanagh.  Ta ny killagyn shoh ny s'cruinney as cha nel ad cho çhionn.  Ta reamyssyn mooarey aer eddyr-chillagagh.  Ta ny sloo chloroplastyn oc na ec killagyn çhionn.

Ta ny stomata fosley dys ny reamyssyn shoh.

Cha nel y daa vrat shoh ec dagh lus ushtagh.  Ny keayrtyn, nagh vel eer epiderm ny mesophyll oc.  T'adsyn jannoo ymmyd jeu aerenchyma co-cheintyssagh: killagyn as boallaghyn keylley oc, as reamyssyn mooar gassagh eddyr oc.  Ta ny stomata oc er yn eaghtyr s'ardjey.

 Cuishlinyn 
thumb|right|Ushylagh cuishlin dy ghuillag Hydrangea
Ta ny cuishlinyn nyn soie 'sy vesophyll thoanagh.  T'ad jeant magh jeh:

 Sylem: feddanyn ta gymmyrkey ushtey as stoo meainagh jeh ny fraueyn dys y duillag.
 Phloem: feddanyn ta gymmyrkey sapp ass y duillag, as sucrose ass co-haaghey sollysh lheieit ayn.

 Jalloo-oaylleeaght 
 Oardagh er y ghass 
thumb|right|Ta ny duillagyn shoh er nyn reaghey dy piyral, as dagh piyr kern-uillinagh rish y nah phiyr ("croshagh").  Ta buinnaghyn aegey ry-akin 'syn aghlish raad ta'n chass duillag kianglt rish y ghass.
 Maylartey — ta un duillag kianglt rish dagh noad, as ta ny duillagyn maylartey er y daa heu harrish y ghass.
 Piyral — ta daa ghuillag kianglt rish adgh noad; t'ad croshagh my ta dagh piyr çhyndaait rere y phiyr roish; t'ad jeeragh my t'ad gaase ayns daa straih er yn un phlaaney.
 Fainagh — ta tree ny ny smoo kianglt rish dagh noad er y ghass.  Ny keayrtyn, ta'n 'ainey croshagh rere yn 'ainey roish.
 Roseagh — ta ny duillagyn ayns cummey cront.

Lesh aase ny gass, ta duillagyn reaghey ad hene mygeayrt y ghass er son dy hareaghey ymmyd sollys.  T'ad jannoo shlig chassee mygeayrt y ghass.  Ta uillin ny duillagyn rere straih Fibonacci: 1/2, 2/3, 3/5, 5/8, 8/13, 13/21, 21/34, 34/55, 55/89. 'sy straih shoh, ta'n earrooder cowraghey yn earroo dy lane hymshal mygeayrt y ghass derrey vees duillag 'syn ynnyd toshee reesht.  Ta'n enmysser cowraghey quoid dy ghuillagyn t'ayn.  Myr shen:

 ta duillagyn maylartey er uillin 180° (myr shen, 1/2 kiarkyl, hoal noi y cheilley)
 120° (1/3) : tree duillagyn ayns çhymshal
 144° (2/5) : queig duillagyn ayns daa hymshal
 135° (3/8) : hoght duillagyn ayns tree çhymshallyn

 Ayrnyn y lhiann 

Ta daa horçh dy ghuillag ry-hoilshaghey bentyn rish rheynn y duillag.  Ta lhiann neurheynnit ec duillag bunneydagh.  Ny keayrtyn, ta cummey y duillag jeant jeh babbanyn, agh cha nel ny baarnaghyn eddyr oc roshtyn yn ard-chuishlin.  Ta lhiann rheynnit ec yl-ghuillag, as dagh duillageen echey rheynnit er ard-chuishlin ny fo-chuishlin.  Ny keayrtyn, t'eh jeeaghyn dy vel dagh duillageen ny ghuillag hene.  Myr shen, she scanshoil eh dy chur tastey er raad ta'n cass duillag, dys cur enney er yl-ghuillag.  T'ad cowreydagh jeh shiartanse dy chynneeyn er lheh, myr sampleyr, Fabaceae.  T'ad cur rachis er cuishlin veanagh y duillag.

 Troyn y chass duillag 
thumb|right|200px|Ta cassyn duillag ro-vooarey rhubarb (Rheum rhabarbarum) yn-ee.

Ta duillagyn as cass oc ayn, as duillagyn gyn cass myrgeddin.  Adsyn gyn cass, ta'n lhiann kianglt dy jeeragh rish y ghass. Foddee y lhiann goll mygeayrt y ghass, as ny keayrtyn, t'eh jeeaghyn dy vel y ghass gaase ny trooid.  Shen feer ec kuse jeu, as t'ad cur thiollit (ny perfoliata) orroosyn, m.s. Claytonia perfoliata.

Ec duillagyn peltata, ta'n cass duillag kianglt rish eaghtyr y lhiann, cha nel rish yn oirr echey.

Ta cass duillag lheanit ec shiartase dy ghooieyn Acacia, as t'ad jannoo obbyr lhiann.  T'ad cur phyllodeyn orroo.  Ny keayrtyn, ta duillag cadjin fedjagagh ec birr y phyllode.

Ta stipule, ry-akin ec ymmodee dicotyledonyn.  She famman gollrish duillag beg t'ayn, as t'ad nyn soie ec çheuyn y chass duillag.  Ta fir foddey beayn ayn nagh vel tuittym (m.s. ayns roseyn as poanraghyn), agh ta fir elley tuittym.

 Oardagh ny cuishlinyn 

thumb|200px|Cuishlinyn banglaneagh er çheu heese duillag taro.

Ta ram termeeaght er lheh bentyn rish cuishlinaght duillagyn.

Ta un aarheynn bentyn rish lheanid ny cuishlinyn:
 craspedodromous (ard-chuishlinyn roshtyn oirr y duillag) 
 camptodromous (cha nel ard-chuishlinyn roshtyn oirr y duillag).

Son y chooid smoo, t'ad aarheynn duillagyn er bun cummey ny banglaneaght ny cuishlinyn.

 Imraaghyn 

Ronney:Co-haaghey sollysh
Ronney:Fyshoaylleeaght lossreeyn
Ronney:Jalloo-oaylleeaght lossreeyn
Ronney:Ronsaghey-kirpey lossreeyn