Ironbark
Ironbark is a common name of a number of species in three taxonomic groups within the genus Eucalyptus that have dark, deeply furrowed bark.
Instead of being shed annually as in many of the other species of Eucalyptus, the dead bark accumulates on the trees, forming the fissures. It becomes rough after drying out and becomes impregnated with kino, a dark red tree sap exuded by the tree. The tree is so named for the apparent resemblance of its bark to iron slag. The bark is resistant to fire and heat and protects the living tissue within the trunk and branches from fire. In cases of extreme fire, where leaves and shoots are removed, the protective bark aids in protecting epicormic buds which allow the tree to reshoot.
Being a very dense, hard wood, a length of ironbark is often used as a bug shoe on the bottom of a ship's skeg to protect it from shipworms. Ironbark was widely used in the piles of 19th and early 20th century bridges and wharves in New Zealand. It was widely used for railway sleepers in eastern Australia in the 19th and 20th centuries due to its durability; while other timber sleepers had to be replaced every 7-12 years, ironbark could last 30 years.
Examples of ironbark species
Eucalyptus ancophila L.A.S.Johnston & K.D.HillEucalyptus atrata L.A.S.Johnston & K.D.Hill Herberton ironbark, blue-leaved ironbarkEucalyptus beaniana L.A.S.Johnson & K.D.Hill Bean's ironbarkEucalyptus caleyi Maiden Caley's ironbark, drooping ironbarkEucalyptus corynodes A.R. Bean & BrookerEucalyptus crebra F.Muell. narrow-leaved ironbark or narrow-leaved red ironbarkEucalyptus cullenii Cambage Cullen's ironbarkEucalyptus decolor A.R.Bean & BrookerEucalyptus decorticans Maiden gum-topped ironbarkEucalyptus dura L.A.S. Johnson & K.D.HillEucalyptus exilipes Brooker & A.R.Bean fine-leaved ironbarkEucalyptus farinosa K.D.HillEucalyptus fibrosa F. Muell. broad-leaved ironbark, blue-leaved ironbarkEucalyptus fusiformis Boland & Kleinig grey ironbark Eucalyptus granitica L.A.S.Johnson & K.D.Hill granite ironbarkEucalyptus indurata Brooker & Hopper ironbarkEucalyptus jensenii Maiden Wandi ironbarkEucalyptus melanoleuca S.T.Blake Yarraman ironbark or nanango ironbarkEucalyptus melanophloia F.Muell. silver-leaved ironbarkEucalyptus ophitica L.A.S.Johnson & K.D.Hill serpentine ironbark Eucalyptus panda S.T. Blake tumbledown ironbark, Yetman ironbarkEucalyptus paniculata Sm. grey ironbarkEucalyptus paedoglauca L.A.S.Johnson & Blaxell Mount Stuart ironbarkEucalyptus placita L.A.S.Johnson & K.D.Hill grey ironbarkEucalyptus quadricostata Brooker square-fruited ironbarkEucalyptus rhombica A.R.Bean & BrookerEucalyptus scopulorum K.D.HillEucalyptus shirleyi Maiden Shirleys's silver leaved ironbarkEucalyptus sicilifolia L.A.S.Johnson & K.D.HillEucalyptus siderophloia Benth. northern grey ironbarkEucalyptus sideroxylon A.Cunn. ex Woolls mugga ironbarkEucalyptus staigeriana F.Muell. ex Bailey lemon-scented ironbarkEucalyptus suffulgens L.A.S.Johnson & K.D.HillEucalyptus taurina A.R.Bean & Brooker Helidon ironbarkEucalyptus tricarpa L.A.S.Johnson & K.D.Hill red ironbarkEucalyptus virens Brooker & A.R.Bean shiny-leaved ironbarkEucalyptus whitei Maiden & Blakely White's ironbark