''Acacia oldfieldii'' is a shrub belonging to the genus ''

Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...

'' and the subgenus ''Juliflorae'' 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 ...

to western

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Description

The bushy shrub typically grows to a height of . It has

glabrous Glabrousness (from the Latin ''glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

branchlets and has citron golden-sericeous new growth. Like most species of ''Acacia'' it has

phyllode Phyllodes are modified petioles or leaf stems, which are leaf-like in appearance and function. In some plants, these become flattened and widened, while the leaf itself becomes reduced or vanishes altogether. Thus the phyllode comes to serve the ...

s rather than true leaves. The patent to reflexed evergreen phyllodes have a linear-elliptic to linear-oblanceolate shape and can be straight to shallowly incurved. The thinly coriaceous and glabrous phyllodes have a length of and a width of and have yellow coloured margins and a straight to recurved tip along with many closely parallel non-prominent nerves. It flowers from June to September producing simple

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

s that are found in pairs in the

axil A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

s with long cylindrical flower-spikes with a diameter of loosely packed with bright golden coloured flowers. Following flowering thinly crustaceous and glabrous

seed pod This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnify ...

s form that have a linear shape and are raised over and constricted between each of the seeds. The pods grow to as long as and have a width of with longitudinally arranged seeds inside. The glossy black seeds have an elliptic shape with a length of and a sub-conical terminal

aril An aril (pronounced ), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode or false aril is sometimes distinguished: whereas an aril grows from the attachment point of the see ...

Taxonomy

The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

was collected by

Augustus Frederick Oldfield Augustus Frederick Oldfield (1821–1887) was an English botanist and zoologist who made large collections of plant specimens in Australia. Oldfield was born on 12 January 1821 in London, England. He made botanical collections in Tasmania, the coa ...

from along the Murchison River and was later formally described by the botanist

Ferdinand von Mueller Baron Sir Ferdinand Jacob Heinrich von Mueller, (german: Müller; 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 Vict ...

in 1863 as part of the work '' Fragmenta Phytographiae Australiae''. It was reclassified as ''Racosperma oldfieldii'' in 2003 by

Leslie Pedley Leslie Pedley (19 May 1930 – 27 November 2018)IPNILeslie Pedley/ref> was an Australian botanist who specialised in the genus ''Acacia''. He is notable for bringing into use the generic name ''Racosperma'', creating a split in the genus, which r ...

then transferred back to genus ''Acacia'' in 2006. 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 ...

honours the collector of the type specimen.

Distribution

It is native to

Mid West The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four Census Bureau Region, census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of ...

region of

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 ...

from around

Northampton Northampton () is a market town and civil parish in the East Midlands of England, on the River Nene, north-west of London and south-east of Birmingham. The county town of Northamptonshire, Northampton is one of the largest towns in England; ...

in the north down to around

Geraldton Geraldton (Wajarri: ''Jambinu'', Wilunyu: ''Jambinbirri'') is a coastal city in the Mid West region of the Australian state of Western Australia, north of the state capital, Perth. At June 2018, Geraldton had an urban population of 37,648. ...

in the south. The plant is often situated on rises and rocky plains and will grow in sandy and clay soils and on sandstone. It is commonly situated in coastal areas from around Eradu in the south east up to

Kalbarri National Park Kalbarri National Park is located north of Perth, in the Mid West region of Western Australia. The major geographical features of the park include the Murchison River gorge which runs for nearly on the lower reaches of the Murchison River. Sp ...

in the north in soils over gravel or sandstone, ironstone and limestone as a part of sandplain shrubland communities often along with ''

Calothamnus ''Calothamnus'' is a genus of shrubs in the family Myrtaceae and is endemic to the south-west of Western Australia. The common names one-sided bottlebrush or claw flower are given to some species due to their having the flowers clustered on ...

'' and ''

Melaleuca ''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles or tea-trees (although the last name is also applied to species of '' Leptospermum''). They range in size ...

'' species.

References

{{Taxonbar, from=Q9567528 oldfieldii Acacias of Western Australia Plants described in 1863 Taxa named by Ferdinand von Mueller

Description

Taxonomy

Distribution

See also

References