''Eucalyptus benthamii'', commonly known as Camden white gum, Bentham's gum, Nepean River gum, kayer-ro or durrum-by-ang, is a species of tree that is

endemic Endemism is the state of a species being found 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 found elsew ...

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

. It has mostly smooth bluish grey or white bark, lance-shaped to curved adult leaves, flower buds arranged in groups of seven, white flowers and cup-shaped, bell-shaped or conical fruit. Eucalyptus benthamii buds

Description

''Eucalyptus benthamii'' is a tree that grows to a height of with a trunk diameter attaining and forms a

lignotuber A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. Other woody plants may develop basal burls as a similar survival strategy, often as a response t ...

. It has smooth bluish grey or white bark which is shed in ribbons, except for about of rough brownish bark at the base of the trunk. The leaves on young plants and on

coppice Coppicing is a traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down. In a coppiced wood, which is called a copse, young tree stems are repeated ...

regrowth are arranged in opposite pairs, egg-shaped to heart-shaped, long, wide and

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

. Adult leaves are lance-shaped to curved, long, wide on a petiole long and the same colour on both sides. The flower buds are arranged in groups of seven on a peduncle long, the individual buds sessile or on a

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

up to long. Mature buds are oval, long, wide with a rounded operculum. Flowering occurs between March and September and the flowers are white. The fruit is a woody cup-shaped, bell-shaped or conical capsule long and wide. Camden white gum is related to '' E. viminalis''. '' Eucalyptus dorrigoensis'' is a species from the

Dorrigo Plateau The Dorrigo Plateau is a plateau in the Northern Tablelands and New England regions of New South Wales, Australia. The plateau forms part of the Great Dividing Range and is sometimes referred to as the Dorrigo and Guy Fawkes Plateau. The highes ...

that was previously classified as a subspecies of ''E. benthamii'', but does not appear especially related.

Taxonomy and naming

''Eucalyptus benthamii'' was first formally described by

Joseph Maiden Joseph Henry Maiden (25 April 1859 – 16 November 1925) was a botanist who made a major contribution to knowledge of the Australian flora, especially the genus ''Eucalyptus''. This botanist is denoted by the author abbreviation when citing ...

and

Richard Hind Cambage Richard Hind Cambage (7 November 1859 – 28 November 1928) was an Australian surveyor and botanist who made important contributions to the description of the genera ''Acacia'' and ''Eucalyptus''. Early life Cambage, son of John Fisher Camba ...

in 1915 from a specimen collected "from the banks of the

Nepean River Nepean River (Darug: Yandhai), is a major perennial river, located in the south-west and west of Sydney, New South Wales, Australia. The Nepean River and its associated mouth, the Hawkesbury River, almost encircles the metropolitan region of ...

near Cobbity". The description was published in '' Journal and Proceedings of the Royal Society of New South Wales''. Maiden and Cambage did not give a reason for the

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''benthamii'') but it is assumed to honour

George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studi ...

. This tree was well-known to the Aboriginal people of the area, who knew it as durrum-by-ang.

Distribution and habitat

Camden white gum grows on alluvial plains on sand or loam over clay along the Nepean River and its tributaries, in tall open forest, where it either forms a pure stand or is found with other eucalypts such as mountain blue gum ('' E. deanei'') and river peppermint ('' E. elata''). Other associated trees include grey box ('' E. moluccana''), forest red gum ('' E. tereticornis''), grey gum ('' E. punctata''), cabbage gum ('' E. amplifolia''), narrow-leaved ironbark ('' E. crebra'') and broad-leaved apple (''

Angophora subvelutina ''Angophora subvelutina'', commonly known as the broad-leaved apple, is a species of tree that is endemic to eastern Australia. It has rough bark on the trunk and branches, lance-shaped to egg-shaped or elliptical adult leaves, flower buds in ...

''), while associated

understory In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abov ...

species include blackthorn (''

Bursaria spinosa ''Bursaria spinosa'' is a small tree or shrub in the family Pittosporaceae. The species occurs mainly in the eastern and southern half of Australia and not in Western Australia and the Northern Territory. Reaching 10 m (35 ft) high, it ...

''), bracken (''

Pteridium esculentum ''Pteridium esculentum'', commonly known as bracken fern, Austral bracken or simply bracken, is a species of the bracken genus native to a number of countries in the Southern Hemisphere. Esculentum means edible. First described as ''Pteris escul ...

'') tantoon ('' Leptospermum polygalifolium'') and fern-leaved wattle (''

Acacia filicifolia ''Acacia filicifolia'', commonly known as fern-leaved wattle, is a plant in the legume family, Fabaceae and is native to eastern Australia. It is a shrub or tree with compound leaves resembling fern fronds, and spherical heads of yellow or brig ...

'').

Conservation

This eucalypt is classified as "vulnerable" under the Australian Government ''

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cultu ...

'' and the New South Wales Government '' Biodiversity Conservation Act 2016''. It is known from two main populations, one near the

Kedumba River The Kedumba River, a perennial river that is part of the Hawkesbury-Nepean catchment, is located in the Blue Mountains and Macarthur regions of New South Wales, Australia. Course and features The Kedumba Creek rises on the eastern side of Wal ...

in the

Blue Mountains National Park The Blue Mountains National Park is a protected national park that is located in the Blue Mountains region of New South Wales, in eastern Australia. The national park is situated approximately west of Sydney, and the park boundary is quite ...

, the other at

Bents Basin State Recreation Area Bents Basin is a protected nature reserve and state park near Wallacia, New South Wales, Australia in the Sydney metropolitan area. The lake basin, which formed at the efflux of the Nepean River from the Hawkesbury Sandstone ( Sydney sandstone) ...

south of Wallacia. Scattered trees are found around Camden, Cobbity and in

Nattai National Park The Nattai National Park is a protected national park that is located in the Macarthur and Southern Highlands regions of New South Wales, in eastern Australia. It is situated approximately southwest of the Sydney central business district a ...

. Some 10,000 trees are estimated to grow at Kedumba and about 400 at Bents Basin. Land clearing and the flooding of most of its distribution to create

Warragamba Dam Warragamba Dam is a heritage-listed dam in the outer South Western Sydney suburb of Warragamba, New South Wales, Warragamba, Wollondilly Shire in New South Wales, Australia. It is a concrete gravity dam, which creates Lake Burragorang, the prima ...

have severely impacted its population.

Use in horticulture

Camden white gum is a fast-growing and adaptable tree in cultivation and is being investigated in South Africa and South America for pulpwood plantations.

References