Editing Eucalyptus (section)

===Bark===
All eucalypts add a layer of [[Bark (botany)|bark]] every year and the outermost layer dies. In about half of the species, the dead bark is shed exposing a new layer of fresh, living bark. The dead bark may be shed in large slabs, in ribbons or in small flakes. These species are known as "smooth barks" and include ''[[Eucalyptus sheathiana|E. sheathiana]]'', ''[[Eucalyptus diversicolor|E. diversicolor]]'', ''[[Eucalyptus cosmophylla|E. cosmophylla]]'' and ''[[Eucalyptus cladocalyx|E. cladocalyx]]''. The remaining species retain the dead bark which dries out and accumulates. In some of these species, the fibres in the bark are loosely intertwined (in stringybarks such as ''[[Eucalyptus macrorhyncha|E. macrorhyncha]]'' or peppermints such as ''[[Eucalyptus radiata|E. radiata]]'') or more tightly adherent (as in the "boxes" such as ''[[Eucalyptus leptophleba|E. leptophleba]]''). In some species (the "ironbarks" such as ''[[Eucalyptus crebra|E. crebra]]'' and ''[[Eucalyptus jensenii|E. jensenii]]'') the rough bark is infused with gum resin.<ref name="CANBR" />

Many species are 'half-barks' or 'blackbutts' in which the dead bark is retained in the lower half of the trunks or stems—for example, ''[[Eucalyptus brachycalyx|E. brachycalyx]]'', ''[[Eucalyptus ochrophloia|E. ochrophloia]]'', and ''[[Eucalyptus occidentalis|E. occidentalis]]''—or only in a thick, black accumulation at the base, as in ''[[Eucalyptus clelandii|E. clelandii]]''. In some species in this category, for example ''[[Eucalyptus youngiana|E. youngiana]]'' and ''[[Eucalyptus viminalis|E. viminalis]]'', the rough basal bark is very ribbony at the top, where it gives way to the smooth upper stems. The smooth upper bark of the half-barks and that of the completely smooth-barked trees and mallees can produce remarkable colour and interest, for example ''[[Eucalyptus deglupta|E. deglupta]]''.<ref name=FieldGuide/>

''[[Eucalyptus globulus|E. globulus]]'' bark cells are able to photosynthesize in the absence of foliage, conferring an "increased capacity to re-fix internal CO<sub>2</sub> following partial defoliation".<ref>{{Cite journal|last=Eyles|display-authors=etal|first=A|date=2009|title=Role of corticular photosynthesis following defoliation in Eucalyptus globulus|journal=Plant, Cell & Environment|volume=32|issue=8|pages=1004–14|doi=10.1111/j.1365-3040.2009.01984.x|pmid=19344333|doi-access=free|bibcode=2009PCEnv..32.1004E }}</ref> This allows the tree to grow in less-than-ideal climates, in addition to providing a better chance of recovery from damage sustained to its leaves in an event such as a fire.<ref>{{Cite journal|last=Saveyn|display-authors=etal|first=A.|date=Summer 2010|title=Woody tissue photosynthesis and its contribution to trunk growth and bud development in young plants|url=http://onlinelibrary.wiley.com/store/10.1111/j.1365-3040.2010.02197.x/asset/j.1365-3040.2010.02197.x.pdf;jsessionid=2DF8853EB94016F034D5922B3E11AB6A.f01t04?v=1&t=j335k1pl&s=2bcf5c5de958a434bce7596540f55ee86e269f4e|journal=Plant, Cell & Environment|volume=33|issue=11|pages=1949–58|via=Wiley|doi=10.1111/j.1365-3040.2010.02197.x|pmid=20561249|doi-access=free|bibcode=2010PCEnv..33.1949S }}</ref>

Different commonly recognised types of bark include:{{cn|date=June 2024}}
* [[Stringybark]]—consists of long fibres and can be pulled off in long pieces. It is usually thick with a spongy texture.
* [[Ironbark]]—is hard, rough, and deeply furrowed. It is impregnated with dried [[kino (gum)|kino]] (a [[sap (plant)|sap]] exuded by the tree) which gives a dark red or even black colour.
* Tessellated—bark is broken up into many distinct flakes. They are [[cork (material)|corkish]] and can flake off.
* Box—has short fibres. Some also show tessellation.
* Ribbon—has the bark coming off in long, thin pieces, but is still loosely attached in some places. They can be long ribbons, firmer strips, or twisted curls.

<gallery class="center">
Apple box bark.jpg|Bark detail of ''[[Eucalyptus angophoroides|E. angophoroides]]'', the apple-topped box
Eucalyptus deglupta-trees.jpg|Coloured bark of ''[[Eucalyptus deglupta|E. deglupta]]'' native to Southeast Asia
Eucalyptus bark.jpg|'Box' bark of ''[[Eucalyptus quadrangulata|E. quadrangulata]]'', the white-topped box
Eucalyptus sideroxylon - bark.jpg|Dark, fissured '[[ironbark]]' of ''[[Eucalyptus sideroxylon|E. sideroxylon]]''
</gallery>