''Eucalyptus tereticornis'', commonly known as forest red gum, blue gum or red irongum, is a species of tree that is native to eastern Australia and southern New Guinea. It has smooth bark, lance-shaped to curved adult leaves, flower buds in groups of seven, nine or eleven, white flowers and hemispherical fruit.

Description

''Eucalyptus tereticornis'' is a tree that typically grows to a height of and forms a lignotuber. The trunk is straight, usually unbranched for more than half of the total height of the tree and has a girth of up to dbh. Thereafter, limbs are unusually steeply inclined for a ''Eucalyptus'' species. The bark is shed in irregular sheets, resulting in a smooth trunk surface coloured in patches of white, grey and blue, corresponding to areas that shed their bark at different times. 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 dull bluish green, egg-shaped leaves that are long and wide. Adult leaves are the same shade of green on both sides, lance-shaped to curved, long and wide, tapering at the base to a petiole long. The flower buds are arranged in leaf axils in groups of seven, nine or eleven 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 an elongated oval shape, long and wide with a conical to horn-shaped operculum that is much longer than the floral cup. Flowering has been recorded in most months and the flowers are white. The fruit is a woody, hemispherical capsule long and wide with the valves prominently protruding.

Taxonomy and naming

''Eucalyptus tereticornis'' was first formally described 1795 by James Edward Smith in '' A Specimen of the Botany of New Holland'' from specimens collected in 1793 from

Port Jackson Port Jackson, commonly known as Sydney Harbour, is a natural harbour on the east coast of Australia, around which Sydney was built. It consists of the waters of Sydney Harbour, Middle Harbour, North Harbour and the Lane Cove and Parramatta ...

First Fleet The First Fleet were eleven British ships which transported a group of settlers to mainland Australia, marking the beginning of the History of Australia (1788–1850), European colonisation of Australia. It consisted of two Royal Navy vessel ...

surgeon and naturalist John White. (Smith's volume was the botanical part of ''Zoology and Botany of New Holland''. The zoological part was written by George Shaw.) 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 ...

(''tereticornis'') is from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

words ''teres'' (becoming ''tereti-'' in the combined form) meaning "

terete Terete is a term in botany used to describe a cross section (geometry), cross section that is circular, or like a distorted circle, with a single surface wrapping around it.Lichen Vocabulary, Lichens of North America Information, Sylvia and S ...

" and ''cornu'' meaning "horn", in reference to the horn-shaped operculum. In 1999

Ian Brooker Murray Ian Hill Brooker Order of Australia, AM (2 June 1934 – 25 June 2016), better known as Ian Brooker, was an Australian botanist. He was widely recognised as the leading authority on the genus ''Eucalyptus''. Ian Brooker was born in Adelai ...

and Andrew Slee described two subspecies and in 2013

Anthony Bean Anthony Russell Bean (born 1957) is an Australian botanist who works at the Queensland Herbarium and Brisbane Botanic Gardens, Mount Coot-tha. Since 1982, he has led the Eucalyptus Study Group of the Society for Growing Australian Plants. Caree ...

described a further two, and the names of these four subspecies are 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 ...

: * ''Eucalyptus tereticornis'' subsp. ''basaltica'' A.R.Bean has opercula that are not expanded at the base, juvenile leaves that are dull bluish, egg-shaped to round, up to one to two times as long as broad, and pedicels long; * ''Eucalyptus tereticornis'' subsp. ''mediana'' Brooker & Slee has opercula that are not expanded at the base, juvenile leaves that are dull bluish, egg-shaped to round, up to one to two times as long as broad, and pedicels long; * ''Eucalyptus tereticornis'' subsp. ''rotunda'' A.R.Bean has opercula that are not expanded at the base, juvenile leaves that are green, round and up to 1.2 times as long as broad; * ''Eucalyptus tereticornis'' Sm. subsp. ''tereticornis'' has opercula expanded at the base and juvenile leaves that are lance-shaped to egg-shaped, and two to three times longer than wide.

Distribution and habitat

The species has a wide distribution, occurring over the widest range of

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

s of any ''Eucalyptus'' species, occurring from southern

Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

at latitude 15°S, to southeastern Victoria at latitude 38°S. The forest red gum is one of the key canopy species of the threatened Cumberland Plain Woodlands. Subspecies ''basaltica'' grows in eucalypt woodland from Kroombit Tops to near Sydney with a disjunct population in the Carnarvon Range. Subspecies ''mediana'' 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 eastern Victoria where it grows near river banks, wetlands, low hills and plains. Subspecies ''rotunda'' is endemic to a small area near Mitchell in Queensland, growing along creek banks. Subspecies ''tereticornis'' is the most widely distributed of the four subspecies and grows in open forest from the Cape York Peninsula in Queensland, to near Bega in southern New South Wales and as far inland as Roma. It is also known from the Central and Oro Provinces in Papua New Guinea.

Uses

The tree has a strong, hard and durable heartwood, with a density of about 1100 kg m⁻³. It is used for construction in heavy engineering, such as for railway sleepers. The leaves of ''E. tereticornis'' are used in the production of cineole based eucalyptus oil.Boland, D.J., Brophy, J.J., and A.P.N. House, ''Eucalyptus Leaf Oils'', 1991,

Gallery

File:Eucalyptus tereticornis - adult leaves.jpg, Adult leaves File:Eucalyptus tereticornis - trunk bark.jpg, Trunk bark File:Eucalyptus tereticornis - trunk.jpg, Trunk File:Eucalyptus tereticornis - upper branches.jpg, Upper branches File:Eucalyptus tereticornis - buds.jpg, Buds File:Eucalyptus tereticornis flowers, capsules, buds and foliage.jpeg, Inflorescence File:Eucalyptus tereticornis - fruit.jpg, Fruit

References