''Acacia orthocarpa'', also commonly known as Pilbara weeping wattle, needle-leaf wattle or straight-podded wattle, is a shrub or tree 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 tropical parts of northern

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 ...

. The indigenous Nyangumarta peoples know it as yartupu.

Description

The erect, spreading and spindly shrub or small tree typically grows to a height of with a diffuse and often weeping habit but sometimes it can be bushy and low-spreading. It has dark grey to grey-brown coloured bark that can be smooth or flaky. The brown, slightly angular branchlets are glabrous and have inconspicuous ridges and obvious

lenticel A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the bark of woody stems and roots of dicotyledonous flowering plants. It functions as a pore, providing a ...

s. 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 evergreen, coriaceous and glabrous phyllodesare straight to curved with a length of and a width of with two semi-prominent lateral nerves and the remainder inconspicuous. It flowers from March to April or June to July producing yellow flowers or sometimes as late as November and is thought to bloom at anytime following large scale rain events. The cylindrical flower-spikes have a length of and are loosely packed with yellow flowers. After flowering woody and erect

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 are usually linear to oblanceolate in shape and taper toward the base. The pods are straight sided or slightly biconvex with a length of and a width of with longitudinal nerves. The dark brown seeds inside are arranged longitudinally or slightly obliquely and have an oblong to elliptic shape with a length of with a narrowly conical

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 species was first 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 1859 as a part of the work ''Contributiones ad Acaciarum Australiae Cognitionem'' as published in the ''Journal of the Proceedings of the Linnean Society, Botany''. It was reclassified as ''Racosperma orthocarpum'' 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 ...

in 1987 then transferred back to genus ''Acacia'' in 2001. 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 ...

is taken from the Greek words ''ortho'' meaning ''straight'' and ''carpos'' meaning ''fruit'' in reference to the straight shape of the seed pods.

Distribution

It is native to central and northern parts of the

Pilbara The Pilbara () is a large, dry, thinly populated region in the north of Western Australia. It is known for its Aboriginal peoples; its ancient landscapes; the red earth; and its vast mineral deposits, in particular iron ore. It is also a glo ...

region including some of the islands in the Burrup Peninsula and the Dampier Archipelago as well as much of the

Kimberley Kimberly or Kimberley may refer to: Places and historical events Australia * Kimberley (Western Australia) ** Roman Catholic Diocese of Kimberley * Kimberley Warm Springs, Tasmania * Kimberley, Tasmania a small town * County of Kimberley, a ...

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 ...

and the range of the plant extends eastward into the southern part of

top end The Top End of Australia's Northern Territory is a geographical region encompassing the northernmost section of the Northern Territory, which aside from the Cape York Peninsula is the northernmost part of the Australian continent. It covers a ra ...

and the central region of the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

and into

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

to the Mount Isa,

Galilee Galilee (; he, הַגָּלִיל, hagGālīl; ar, الجليل, al-jalīl) is a region located in northern Israel and southern Lebanon. Galilee traditionally refers to the mountainous part, divided into Upper Galilee (, ; , ) and Lower Galil ...

and Georgetown areas where it is found on rocky hills, along rocky creeks and on sandy flats growing in skeletal sandy or loamy soils as a part of savannah woodland and open ''

Eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as euca ...

'' shrubland communities usually with an understorey of spinifex grasses.

References

{{Taxonbar, from=Q15288054 orthocarpa Acacias of Western Australia Flora of Queensland Flora of the Northern Territory Plants described in 1859 Taxa named by Ferdinand von Mueller

Description

Taxonomy

Distribution

See also

References