''Eucalyptus rudis'', commonly known as flooded gum or moitch, is a species of small to medium-sized tree

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 else ...

to coastal areas near

Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth i ...

, Western Australia. The

Noongar The Noongar (, also spelt Noongah, Nyungar , Nyoongar, Nyoongah, Nyungah, Nyugah, and Yunga ) are Aboriginal Australian peoples who live in the south-west corner of Western Australia, from Geraldton on the west coast to Esperance on the so ...

names for the tree are colaille, gooloorto, koolert and moitch. This tree has rough, fibrous bark on the trunk and large branches, smooth greyish bark above, lance-shaped to curved adult leaves, flower buds in groups of between seven and eleven, white flowers and bell-shaped, cup-shaped or hemispherical fruit.

Description

''Eucalyptus rudis'' is a tree that typically grows to a height of 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 ...

. The trunk is usually short and has a poor form with a wide-spreading crown. It has rough, dark and light grey box-style bark on the trunk and larger branches, smooth greyish bark above. Young plants and

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 repeate ...

regrowth have stems that are square in cross-section and dull greyish green, egg-shaped to more or less round leaves that are long and wide. Adult leaves are arranged alternately, lance-shaped to curved, long and wide, tapering to a petiole wide. 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. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

long. Mature buds are oval to diamond-shaped, long and wide conical operculum. Flowering mainly occurs from July to November and the flowers are white. The fruit is a woody, bell-shaped, cup-shaped or hemispherical capsule long and wide with the valves protruding strongly. North of Perth, ''E. rudis'' intergrades with ''Eucalyptus camaldulensis'' var. ''obtusa'' so the bark may be smooth and very similar to '' Eucalyptus camaldulensis''.

Taxonomy and naming

''Eucalyptus rudis'' was first formally described in 1837 by Stephan Endlicher in ''

Enumeratio plantarum quas in Novae Hollandiae ora austro-occidentali ad fluvium Cygnorum et in sinu Regis Georgii collegit Carolus Liber Baro de Hügel ''Enumeratio plantarum quas in Novae Hollandiæ ora austro-occidentali ad fluvium Cygnorum et in sinu Regis Georgii collegit Carolus Liber Baro de Hügel'' is a description of the plants collected at the Swan River colony and King George Sound in ...

'' authored by Endlicher,

Eduard Fenzl Eduard Fenzl (1808, in Krummnußbaum – 1879, in Vienna) was an Austrian botanist. Life and contributions An obituary notes " was Professor of Botany and Director of the Imperial Botanical Cabinet, a member of the Vienna Academy of Sciences, ...

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 studie ...

and

Heinrich Wilhelm Schott Heinrich Wilhelm Schott (7 January 1794 in Brünn (Brno), Moravia – 5 March 1865 at Schönbrunn Palace, Vienna) was an Austrian botanist well known for his extensive work on aroids (Araceae). He studied botany, agriculture and chemistry at ...

from samples collected by

Charles von Hügel Charles von Hügel (born Carl Alexander Anselm Baron von Hügel; 25 April 1795 – 2 June 1870), sometimes spelt in English Huegel, was an Austrian nobleman, army officer, diplomat, botanist, and explorer, now primarily remembered for his t ...

around the Swan River Colony. In 1993,

Ian Brooker Murray Ian Hill Brooker 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 Adelaide, South Australi ...

and Stephen Hopper described two subspecies and the names have been 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 Syst ...

: * ''Eucalyptus rudis'' subsp. ''cratyantha'' Brooker and Hopper has buds up to long and fruit up to wide; * ''Eucalyptus rudis'' Endl. subsp. ''rudis'' has buds up to long and fruit up to wide.

Distribution and habitat

The tree is widespread from the Eneabba district (29° S. Lat.) southwards in the

Darling Range The Darling Scarp, also referred to as the Darling Range or Darling Ranges, is a low escarpment running north–south to the east of the Swan Coastal Plain and Perth, Western Australia. The escarpment extends generally north of Bindoon, to t ...

, west central wheatbelt and high rainfall areas of south-west

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

commonly on watercourses, swampy ground or very occasionally on granite rock.Brooker & Kleinig, Field Guide to Eucalypts, Vol 2 South Western and Southern Australia, Bloomings Books, Melbourne, 2001, Subspecies ''cratyantha'' only occurs from

Mandurah Mandurah () is a coastal city in the Australian state of Western Australia, situated approximately south of the state capital, Perth. It is the state's second most populous city, with a population of 107,641 as of the 2021 census. Mandurah's ...

and Pinjarra south and south-west to

Cape Naturaliste Cape Naturaliste is a headland in the south western region of Western Australia at the western edge of the Geographe Bay. It is the northernmost point of the Leeuwin-Naturaliste Ridge which was named after the cape. Also the Leeuwin-Naturaliste ...

. Flooded gum occurs typically in open woodlands, associated species include with '' wandoo'', ''

Corymbia calophylla ''Corymbia calophylla'', commonly known as marri, is a species of flowering plant in the family Myrtaceae and is endemic to the southwest of Western Australia. It is a tree or mallee with rough bark on part or all of the trunk, lance-shaped ad ...

'' and ''

Eucalyptus marginata ''Eucalyptus marginata'', commonly known as jarrah, djarraly in Noongar language and historically as Swan River mahogany, is a plant in the myrtle family, Myrtaceae and is endemic to the south-west of Western Australia. It is a tree with rough ...

''.

Ecology

This tree is often heavily attacked in spring by insects, including

leaf miner A leaf miner is any one of numerous species of insects in which the larval stage lives in, and eats, the leaf tissue of plants. The vast majority of leaf-mining insects are moths ( Lepidoptera), sawflies ( Symphyta, the mother clade of wasp ...

s, leaf blister

sawflies Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay ...

and lerps. The

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

regenerates in late spring and into summer.

Conservation status

Subspecies ''rudis'' is classified as "not threatened" in Western Australia by the Western Australian Government

Department of Parks and Wildlife The Department of Parks and Wildlife (DPaW) was the department of the Government of Western Australia responsible for managing lands described in the ''Conservation and Land Management Act 1984'' and implementing the state's conservation and e ...

, but subspecies ''cratyantha'' is classified as " Priority Four" by the Government of Western Australia

, meaning that is rare or near threatened.

Uses

The tree is relatively fast-growing with potential for remediation of land affected by moderate levels of salinity. Natural stands are used in the apiculture industry as a source of pollen producing a light amber honey. It is also being assessed as a fast-growing source of biomass for bioenergy and reconstituted wood products in the

South West The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each se ...

region. Historically it has been used as firewood but the wood also has potential for use as specialty timber. The heartwood is hard, cross grained and a yellow to light reddish brown colour. It has a green density is about kg/m³, and air-dried density about 775 kg/m³.

References

{{Taxonbar, from=Q568002 rudis Trees of Australia Myrtales of Australia Eucalypts of Western Australia Trees of Mediterranean climate Plants described in 1837 Taxa named by Stephan Endlicher