''Acacia sphacelata'' is a shrub of 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 ''Phyllodineae'' 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 south 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 harsh shrub typically grows to a height of .
[ It has light grey to mid-grey coloured bark and ]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 ...
to minutely hairy and rigid branchlets with persistent or caducous stipule
In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...
s that have a length of . 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 scattered, patent, linear or nearly lanceolate phyllodes form in whorls around the stem and have no stems. The evergreen phyllodes are straight to shallowly curved and quadrangular or flat with a length of and a width of and are smooth, pungent, glabrous, rigid and pungent with five main nerves.[ The 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 usually occur singly 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 on stalks that are in length. The showy spherical flower-heads contain 13 to 50 bright yellow flowers. After flowering papery to crustaceous 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 narrowly oblong to linear shape. The glabrous pods have a length of up to and a width of containing longitudinally arranged seeds inside. The dark brown to black coloured 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 ...
late seeds have a length of .[
]
Taxonomy
The species was first formally described by the botanist 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 ...
in 1842 as part of the William Jackson Hooker
Sir William Jackson Hooker (6 July 178512 August 1865) was an English botanist and botanical illustrator, who became the first director of Kew when in 1841 it was recommended to be placed under state ownership as a botanic garden. At Kew he ...
work ''Notes on Mimoseae, with a synopsis of species'' as published in the ''London Journal of Botany''. It was reclassified as ''Racosperma sphacelatum'' 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 2003 then transferred back to the ''Acacia'' genus in 2006. The only other synonyms are ''Acacia sphacelata'' var. ''sphacelata'', ''Acacia tamminensis'' and ''Acacia spacelata''.
There are three recognised subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
:
* ''Acacia sphacelata'' subsp. ''recurva''
* ''Acacia sphacelata'' subsp. ''sphacelata''
* ''Acacia sphacelata'' subsp. ''verticillata''
Distribution
It is native to an area in the 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 ...
, Wheatbelt and Goldfields-Esperance regions 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 ...
where it is often situated on undulating plains and lateritic
Laterite is both a soil and a rock type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by ...
rises where it grows in sandy, sandy-clay and loamy soils.Port Gregory
Gregory (Port Gregory until 1967) is a small town and fishing port located northwest of the mouth of the Hutt River, in the Mid West region of Western Australia. At the 2016 census, Gregory had a population of 64 in 83 dwellings. Most of the ...
in the north west down to around the Stirling Range
The Stirling Range or Koikyennuruff is a range of mountains and hills in the Great Southern region of Western Australia, south-east of Perth. It is over wide from west to east, stretching from the highway between Mount Barker and Cranb ...
in the south and out to around Scaddan in the east.[
]
See also
* List of ''Acacia'' species
References
{{Taxonbar, from=Q15289007
sphacelata
Acacias of Western Australia
Taxa named by George Bentham
Plants described in 1842