''Eucalyptus leucoxylon'', commonly known as yellow gum, blue gum or white ironbark, is a species of small to medium-sized tree that is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to south-eastern continental

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. It has smooth yellowish bark with some rough bark near the base, lance-shaped or curved adult leaves, flower buds in groups of three and cylindrical, barrel-shaped or shortened spherical fruit. A widely cultivated species, it has white, red or pink flowers. Eucalyptus leucoxylon buds

Description

''Eucalyptus leucoxylon'' is a tree that typically grows to a height of and forms a lignotuber. It has smooth white, yellow or bluish-grey bark, usually with of rough fibrous to flaky bark the base of the trunk. Young plants and

coppice Coppicing is the traditional method in woodland management of cutting down a tree to a tree stump, stump, which in many species encourages new Shoot (botany), shoots to grow from the stump or roots, thus ultimately regrowing the tree. A forest ...

regrowth have leaves mostly arranged in opposite pairs, egg-shaped to broadly lance-shaped, long and wide. Adult leaves are arranged alternately, the same slightly glossy shade of green on both sides, lance-shaped to curved, long and wide, tapering to a petiole long. The flower buds are arranged in groups of three in leaf axils on an unbranched peduncle long, the individual buds on

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branch ...

long. Mature buds are oval to diamond-shaped or more or less spherical, long, wide with a conical to rounded or beaked operculum. Flowering has been recorded in most months and the flowers a white, red or pink. The fruit is a woody, cylindrical, barrel-shaped or shortened spherical capsule long, wide with the valves enclosed below rim level. This species is similar to '' E. melliodora'' and ''E. sideroxylon'' subsp. ''sideroxylon'' but differs in having three buds in each group of flowers.

Taxonomy and naming

''Eucalyptus leucoxylon'' was first formally described in 1855 by

Ferdinand von Mueller Baron Sir Ferdinand Jacob Heinrich von Mueller, (; 30 June 1825 – 10 October 1896) was a German-Australian physician, geographer, and most notably, a botanist. He was appointed government botanist for the then colony of Victoria, Australia ...

in the ''Transactions and Proceedings of the Victorian Institute for the Advancement of Science''. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

(''leucoxylon'') is derived from the

ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

''leuco-'' meaning "white" and ''-xylon'' meaning "wood".

Subspecies and varieties

The subspecies and varieties accepted by the

Australian Plant Census The Australian Plant Census (APC) provides an online interface to currently accepted, published, scientific names of the vascular flora of Australia, as one of the output interfaces of the national government Integrated Biodiversity Information Sys ...

(APC) as at September 2019 are: * ''Eucalyptus leucoxylon'' subsp. ''bellarinensis'' Rule has fibrous-flaky bark near the base of the trunk, waxy juvenile leaves that have the opposite pairs joined to each other, more or less spherical flower buds and relatively large fruit on a long pedicel; * ''Eucalyptus leucoxylon'' subsp. ''connata'' Rule is similar to the autonym (subsp. ''leucoxylon'') but has more or less spherical, rather than oval, flower buds; * '' Eucalyptus leucoxylon'' F.Muell. ''leucoxylon'' does not have waxy leaves, the juvenile leaves are never joined in pairs, adult leaves less than wide, pedicels equal to or longer than the fruit, and oval flower buds; * ''Eucalyptus leucoxylon'' subsp. ''megalocarpa'' Boland is similar to the autonym but has adult leaves more than wide; * ''Eucalyptus leucoxylon'' var. ''pluriflora''; F.Muell. ex Miq. * ''Eucalyptus leucoxylon'' subsp. ''pruinosa'' (F.Muell. ex Miq.) Boland has surface wax present on the juvenile leaves, flower buds and fruit, and has white flowers.

Distribution and habitat

This eucalypt species is found in Victoria, south-eastern South Australia and far south-western New South Wales. All six subspecies occur in Victoria. Subspecies ''bellarinensis'' is only known from the Bellarine Peninsula near Ocean Grove and Torquay. Subspecies ''connata'' grows on skeletal soils, mostly in the Brisbane Ranges. Subspecies ''leucoxylon'' is the most widespread species and occurs in scattered populations across Victoria and in south-eastern South Australia, including on

Kangaroo Island Kangaroo Island (, ) is Australia's third-largest island, after Tasmania and Melville Island, Northern Territory, Melville Island. It lies in the state of South Australia, southwest of Adelaide. Its closest point to the mainland is Snapper Poi ...

where the tallest specimens are found. Subspecies ''megalocarpa'' is a stunted tree or mallee only found in coastal areas from the far south-east of South Australia to far western Victoria. Subspecies ''pruinosa'' occurs in drier areas of South Australia, the

Wimmera The Victorian government's Wimmera Southern Mallee subregion is part of the Grampians region in western Victoria. It includes most of what is considered the Wimmera, and part of the southern Mallee region. The subregion is based on the social ...

and Goldfields of Victoria and on the

Murray River The Murray River (in South Australia: River Murray; Ngarrindjeri language, Ngarrindjeri: ''Millewa'', Yorta Yorta language, Yorta Yorta: ''Dhungala'' or ''Tongala'') is a river in Southeastern Australia. It is List of rivers of Australia, Aust ...

floodplain near Barham in New South Wales.

Uses

Essential oils

The leaves are distilled for the production of cineole based eucalyptus oil.

Use in horticulture

Subspecies ''megalocarpa'' is a relatively small tree with red flowers and large fruit and is often available under the horticultural name ‘Rosea’. It flowers profusely in winter, and is widely planted as an

ornamental plant Ornamental plants or ''garden plants'' are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars th ...

. 'Euky Dwarf' is grown as a street and garden tree, growing to a height of tall and wide. Subspecies ''leucoxylon'' has been recommended for larger gardens and parklands. Image:Eucalyptus leucoxylon1.jpg, ''E. leucoxylon'' subsp. ''megalocarpa'' Image:Eucalyptus leucoxylon pruinosa.jpg, waxy leaves of subsp. ''pruinosa''

References

{{Taxonbar, from=Q161468 leucoxylon Myrtales of Australia Trees of Australia Flora of South Australia Flora of Victoria (state) Flora of New South Wales Plants described in 1855 Trees of Mediterranean climate Ornamental trees Taxa named by Ferdinand von Mueller