{{Short description|Classifications of plant leaves by size}} '''Leaf size''' of plants can be described using the terms '''''megaphyll''''', '''''macrophyll''''', '''''mesophyll''''', '''''microphyll''''', '''''nanophyll''''' and '''''leptophyll''''' (in descending order) in a classification devised in 1934 by Christen C. Raunkiær and since modified by others.<ref name=whitten>{{cite book|last1=Whitten|first1=Tony|title=Ecology of Java and Bali|date=1996|isbn=9789625930725|page=505|publisher=Periplus Editions (HK) Limited |url=https://books.google.com/books?id=_pIcG_aZGjsC&q=microphyll+mesophyll+notophyll&pg=PA505|accessdate=18 January 2016}}</ref> Definitions vary, some referring to length and others to area. Raunkiaer's original definitions were by leaf area, and differed by a factor of nine at each stage.<ref>{{cite web|title=Climate adaptation: Leaf size and shape|url=http://agron-www.agron.iastate.edu/courses/Agron541/classes/541/lesson11a/11a.3.html|website=Agronomy 541: Applied agricultural meteorology|publisher=Iowa State University Department of Agronomy|accessdate=18 January 2016|archive-date=28 December 2015|archive-url=https://web.archive.org/web/20151228174614/http://agron-www.agron.iastate.edu/courses/Agron541/classes/541/lesson11a/11a.3.html|url-status=dead}}</ref> Some authors have simplified the system to make it specific to particular climates,<ref name=webb/> and have introduced extra terms including '''''notophyll''''',<ref name=webb/> '''''picophyll''''',<ref name=van-der-maarel /> '''''platyphyll'''''<ref name=van-der-maarel /> and '''''subleptophyll'''''.<ref name=ingrouille />
In ecology, microphyll and similar terms based on blade size of the leaf are used to describe a flora, for example, a "microphyll rainforest" is often defined as a forest where the dominant trees have leaves less than 7.5 cm in length.<ref>{{citation |url=http://www.wettropics.gov.au/site/user-assets/docs/factsheets/wtmaVMWTB14a17b.pdf |title=Microphyll rainforests and thickets of the wet tropics bioregion |publisher=Wet Tropics Management Authority (Australia) |accessdate=18 January 2016}}</ref><ref>{{Citation | author1=Tracey, J. G. (John Geoffrey) | author-link=Geoff Tracey | title= The Vegetation of the Humid Tropical Region of North Queensland | publication-date=1982 | pages=32,34,26 | url= https://trove.nla.gov.au/work/23224781?q&versionId=45832425}}</ref>
==Raunkiaer's work== Christen C. Raunkiaer proposed using leaf size as a relatively easy measurement that could be used to compare the adaptation of a plant community to dryness. <blockquote>We have for a long time been aware of a series of different adaptations in the structure of plants enabling them to endure excessive evaporation, and thus allowing them to live in place where the environment determines intense evaporation, or where the conditions of water absorption of the ground are unfavourable either physically or physiologically. Examples of such structures are: (1) covering of wax, (2) thick cuticle, (3) sub-epidermal protective tissue, (4) water tissue, (5) covering of hairs (6) covering of the stomata, (7) sinking of the stomata, (8) inclusion of the stomata in a space protected from air currents, (9) diminution of the evaporating surface, &c. The matter however is so complicated that it is very difficult to reach an exact appraisal of these adaptations in characterizing the individual plant communities biologically. ... In general we must content ourselves with showing the most frequently occurring adaptations, without going farther into the statistical investigation. ... A preliminary direct consideration of a series of evergreen phanerophytic communities, ... show that amongst the adaptations named, diminution of the transpiring surface, diminution in leaf size, is one of the adaptations generally in evidence; and since this adaptation is easy to observe and comparatively easy to measure, it is convenient to begin with it if we wish to use the statistical method on this domain.<ref>{{citation |author=Raunkiaer, C. |year=1934 |title=The life forms of plants and statistical biogeography |chapter=The use of leaf size in bioloical plant geography |publisher=Clarendon |location=Oxford |editor=A.G.T. H. Gilbert-Carter, and A. Fausbøll |pages=368–378 }}</ref></blockquote>
Raunkiaer used the following size classes: *Leptophyll: less than 25 square millimetres *Nanophyll: 25–225 square millimetres *Microphyll: 225-2,025 square millimetres *Mesophyll: 2,025-18,225 square millimetres *Macrophyll: 18,225-164,025 square millimetres *Megaphyll: greater than 164,025 square millimetres
Later authors have modified the classes and have sometimes used leaf length as a simpler measure than leaf area if the leaf shape is approximately an ellipse. For example, L.J. Webb<ref name=webb>{{citation |author=Webb, L.J. | author-link=Leonard Webb (academic) | year=1959 |title=A Physiognomic Classification of Australian Rain Forests |journal=Journal of Ecology |volume=47 |issue=3 |pages=551–570 |jstor=2257290 |doi=10.2307/2257290 | bibcode=1959JEcol..47..551W }} Figure 2</ref> used size classes: *Microphyll: less than 2,025 square millimetres *Notophyll: 2,025–4,500 square millimetres *Mesophyll: greater than 4,500 square millimetres
==Examples of definitions== {| class="wikitable" |+Examples of definitions of the categories of leaf size |- ! Classification !! Raunkiaer quoted by Dash<ref name=dash>{{cite book|last1=Dash|title=Fundamentals of Ecology|date=2009|publisher=Tata McGraw Hill Education|isbn=9780070083660|page=225|url=https://books.google.com/books?id=Sh0gGdB5_P8C&q=megaphyll+classification&pg=PA225|accessdate=18 January 2016}}</ref>!! Webb <ref name=webb /> !! Whitten et al<ref name=whitten />!!Ingrouille<ref name=ingrouille>{{cite book | last=Ingrouille | first=M|title= Diversity and Evolution of Land Plants|url=https://books.google.com/books?id=JwfwCAAAQBAJ&q=leptophyll+microphyll&pg=PA260 | publisher=Springer Science & Business Media | date=2012 | page=260 | isbn=9789401123006| accessdate=18 January 2016}}</ref> <small>Converted to mm<sup>2</sup> for ease of comparison</small>!!van der Maarel<ref name=van-der-maarel>{{cite book|last1=Van der Maarel|first1=Eddy|author-link1=Eddy van der Maarel|title=Vegetation Ecology|date=2012|publisher=Wiley|isbn=9781118452486|edition=2nd|chapter-url=https://books.google.com/books?id=bY_VpioznAAC&q=leptophyll+microphyll&pg=PT388|accessdate=18 January 2016|chapter=12.3.4 Functional traits}}</ref>!!Boland et al<ref name=boland>{{cite book|last1=Boland|first1=D J|title=Forest Trees of Australia|date=2006|publisher=Csiro Publishing|page=692|isbn=9780643098947|url=https://books.google.com/books?id=CRQg11hSJ1kC&q=microphyll+mesophyll+notophyll&pg=PA692|accessdate=18 January 2016}}</ref> !! Wet Tropics Mgmt Authority<ref name=wet-tropics>{{cite web|title=Classifying rainforests|url=http://www.wettropics.gov.au/rainforest|publisher=Wet Tropics Management Authority|accessdate=18 January 2016}}</ref> |- |Megaphyll ||> 164,025 mm<sup>2</sup>|| || || > 164,000 mm<sup>2</sup>||> 180,000 mm<sup>2</sup> || || |- |Macrophyll || 18,225-164,025 mm<sup>2</sup>|| || || 18,000-164,000 mm<sup>2</sup>||36,400-180,000 mm<sup>2</sup>|| || |- |Platyphyll || || || || ||18,200-36,400 mm<sup>2</sup>|| || |- | Mesophyll|| 2,025-18,225 mm<sup>2</sup>||> 4,500 mm<sup>2</sup>|| 4,500-18,225 mm<sup>2</sup> ||5,600-18,000 mm<sup>2</sup>||4,500-18,200 mm<sup>2</sup>|| > 12.7 cm || > 12.5 cm |- | Notophyll|| ||2,025–4,500 mm<sup>2</sup>|| 2,025–4500 mm<sup>2</sup> || ||2,025-4,500 mm<sup>2</sup> ||7.6-12.7 cm || 7.5-12.5 cm |- |Micro-mesophyll || || || ||2,000-5,600 mm<sup>2</sup>|| || || |- | Microphyll||225-2,025 mm<sup>2</sup> ||< 2,025 mm<sup>2</sup>|| 225-2,025 mm<sup>2</sup> || 1,200-2,000 mm<sup>2</sup>||225-2,025 mm<sup>2</sup>|| 2.5-7.6 cm|| < 7.5 cm |- |Nano-microphyll || || || ||200-1,200 mm<sup>2</sup>|| || || |- |Nanophyll||25–225 mm<sup>2</sup> || || < 225 mm<sup>2</sup> ||25–200 mm<sup>2</sup>||25–225 mm<sup>2</sup>||< 2.5 cm || |- |Leptophyll ||< 25 mm<sup>2</sup> || || ||10–25 mm<sup>2</sup>||2–25 mm<sup>2</sup>|| || |- |Subleptophyll || || || ||< 10 mm<sup>2</sup>|| || || |- |Picophyll || || || || ||< 2 mm<sup>2</sup>|| || |}
== Single vegetable organisms with large leaves ==
*''Gunnera manicata'', giant ornamental rhubarb; leaves {{cvt|2|x|3.4|m}};<ref name="goe">{{cite web |url=https://gardenofeaden.blogspot.com/2015/07/what-is-worlds-largest-leaf.html |title=What is the World's Largest Leaf? |website=The Garden of Eden |access-date=September 28, 2018}}</ref> *''Raphia regalis'', composed leaves {{cvt|25.11|x|3|m}};<ref name="goe"/> *''Manicaria saccifera'', Amazonian palm; partially composed leaves {{cvt|8|m}};<ref name="goe"/> *''Marojejya darianii'', big-leaf palm; leaves {{cvt|5|m}};<ref name="goe"/> *''Johannesteijsmannia altifrons'', Joey palm; undivided leaves {{cvt|4|m}} long;<ref name="goe"/> *''Amorphophallus titanum'', titan arum; leaves area {{cvt|34|sqft|m2|order=flip}};<ref name="goe"/> *''Victoria amazonica'', giant Amazonian waterlily; aquatic plant with leaves {{cvt|8|ft|m|order=flip}} long; leaves area {{cvt|50|sqft|m2|order=flip}}.<ref name="goe"/>
==See also== *Leaf
==References== {{reflist}}
Category:Ecological metrics Category:Leaf morphology