{{Short description|Species of legume}} {{redirect|Brigalow|the town in Australia|Brigalow, Queensland}} {{Use Australian English|date=August 2021}} {{Use dmy dates|date=August 2021}} {{Speciesbox |name = Brigalow |image = Brigalow leaves and blossom.jpg |genus = Acacia |species = harpophylla |authority = [[F.Muell.]] ex [[Benth.]]<ref name="APC">{{cite web |title=''Acacia harpophylla'' |url=https://biodiversity.org.au/nsl/services/apc-format/display/64199 |publisher=Australian Plant Census |access-date=7 March 2026}}</ref> |status = LC |status_system = IUCN3.1 |status_ref = <ref>{{cite iucn |author=IUCN SSC Global Tree Specialist Group. |author2=Botanic Gardens Conservation International (BGCI). |year=2020 |title=''Acacia harpophylla'' |volume=2020 |article-number=e.T177369097A177369099 |doi=10.2305/IUCN.UK.2020-3.RLTS.T177369097A177369099.en |access-date=11 July 2024}}</ref> |synonyms_ref = <ref name="APC" /> |synonyms = ''Racosperma harpophyllum'' <small>(Benth.) [[Leslie Pedley|Pedley]]</small> |range_map = Acacia harpophyllaDistMap420.png |range_map_caption = Occurrence data from [[Australasian Virtual Herbarium|AVH]] }}
[[File:Brigalow tree.jpg|thumb|right|Remnant brigalow tree, coastal central Queensland, ~20m tall]] [[File:Brigalow bark.jpg|thumb|right|Brigalow bark]] '''''Acacia harpophylla''''', commonly known as '''brigalow''', '''brigalow spearwood''', '''orkor''' or '''ogarah''',<ref name="FoA">{{cite web |last1=Cowan |first1=Richard S. |title=''Acacia harpophylla'' |url=https://profiles.ala.org.au/opus/foa/profile/Acacia%20harpophylla |publisher=Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra. |access-date=7 March 2026}}</ref> is a species of flowering plant in the family [[Fabaceae]] and is [[endemic]] to eastern Australia. It is a tree with sickle-shaped [[phyllode]]s, spherical heads of golden yellow flowers and sub[[terete]] straight to slightly curved [[Pod (fruit)|pods]], slightly raised over and constricted between the seeds. The [[Gamilaraay]] peoples know the tree as '''barranbaa''' or '''burrii'''.<ref name=atlas>{{cite web|url=https://bie.ala.org.au/species/http://id.biodiversity.org.au/node/apni/2887238#names|title=''Acacia harpophylla'' F.Muell. ex Benth.|access-date=9 October 2019|work=Atlas of Living Australia|publisher=[[Global Biodiversity Information Facility]]}}</ref>It is found in central and coastal [[Queensland]] to northern [[New South Wales]]. It can reach up to {{cvt|25|m}} tall and forms extensive open-forest communities on clay soils.<ref name=www/>
==Description== ''Acacia harpophylla'' is a root-suckering tree that typically grows to a height of up to {{cvt|25|m}}, and has hard, furrowed and almost black bark. Its branchlets are covered with soft hairs, pressed against the surface, or [[wikt:glabrous|glabrous]]. Its phyllodes are sickle-shaped, {{cvt|100–200|mm}} long, {{cvt|7–20|mm}} wide, leathery and covered with silky hairs, with many closely parallel veins of which three to seven are more prominent than the rest. Its flowers are borne in spherical heads in two to eight [[raceme]]s on [[Peduncle (botany)|peduncles]] mostly {{cvt|10–20|mm}} long and covered with soft hairs. Each head is {{cvt|5–8|mm}} in diameter with 15 to 35 golden yellow flowers. Flowering occurs between July and October,<ref name=nsw>{{cite web|url=http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Acacia~harpophylla|title=''Acacia harpophylla'' F.Muell. ex Benth.|work=PlantNet|access-date=9 October 2019|publisher=[[Royal Botanic Gardens, Sydney]]}}</ref> and the pods are subterete, straight to slightly curved, up to {{cvt|200|mm}} long and {{cvt|5–10|mm}} wide, crusty and glabrous, slightly raised over and constricted between the seeds. The seeds are oblong or broadly elliptic, flat but thick, {{cvt|10–18|mm}} long and soft, with a thread-like attachment but no [[aril]].<ref name="FoA" /><ref name=www>{{cite web|url=https://worldwidewattle.com/speciesgallery/harpophylla.php|title=''Acacia harpophylla''|access-date=9 October 2019|work=WorldWideWattle|publisher=[[Western Australian Herbarium]]}}</ref><ref name="lucid">{{cite web |title=''Acacia harpophylla'' |url=https://apps.lucidcentral.org/wattle/text/entities/acacia_harpophylla.htm |publisher=Australian Biological Resources Study |access-date=7 March 2026}}</ref>
==Taxonomy== ''Acacia harpophylla'' was first formally described in 1864 by [[George Bentham]] in ''[[Flora Australiensis]]'' from an unpublished description by [[Ferdinand von Mueller]] of specimens collected by [[Anthelme Thozet]] near [[Rockhampton]].<ref name="APNI">{{cite web |title=''Acacia harpophylla'' |url=https://biodiversity.org.au/nsl/services/rest/instance/apni/470577 |publisher=Australian Plant Name Index |access-date=7 March 2026}}</ref><ref name="Benth.">{{cite book |last1=Bentham |first1=George |title=Flora Australiensis |volume=2 |date=1864 |publisher=Lovell Reeve & Co. |location=London |page=389 |url=https://www.biodiversitylibrary.org/page/26122845#page/403/mode/1up |access-date=7 March 2026}}</ref> The [[specific epithet]] (''harpophylla'') refers to the curved phyllodes.<ref name="FoA" />
==Distribution and habitat== Two species, brigalow (''A. harpophylla'') and gidgee ([[Acacia cambagei|''A. cambagei'']]) form open woodlands on flat and gently undulating terrain on heavy and relatively fertile clay and clay-loam soils primarily in the 300-700mm annual rainfall region of Eastern Australia. These woodlands extend from a northern extreme of 20° S into northern New South Wales. Brigalow and gidgee occur as mixed communities in some regions and are commonly associated with several other woody species, including overstorey species such as ''[[Eucalyptus coolabah]]'', [[Eucalyptus cambageana|''E. cambageana'']], ''[[Casuarina cristata]]'', and a range of understorey species.<ref>Scanlan, J. C. (1988). Managing tree and shrub populations. Native pastures in Queensland their resources and management. W. H. Burrows, J. C. Scanlan and M. T. Rutherford. Queensland, Queensland Government Press.</ref><ref name="Anderson, E 1990">Anderson, E. and P. Back (1990). Fire in brigalow lands. Fire in the management of northern Australian pastoral lands. T. C. Grice and S. M. Slatter. St. Lucia, Australia, Tropical Grassland Society of Australia.</ref> [[Acacia tephrina|''A. tephrina'']], [[Acacia georginae|''A. georginae'']] and [[Acacia argyrodendron|''A. argyrodendron'']] also occupy similar habitats and have similar habits and growth forms, but are less widespread, while a number of other ''Acacia'' species also form structurally similar communities.<ref name="Johnson, R. W 1994">Johnson, R. W. and W. H. Burrows (1994). Acacia open forest, woodlands and shrublands. Australian Vegetation. R. H. Groves. Cambridge, Cambridge University Press.</ref>
Brigalow occurs from coastal regions receiving in excess of {{cvt|900|mm}} rainfall per year through to the semiarid {{cvt|500|mm}} rainfall region although it is primarily a semiarid zone species.<ref name="Anderson, E 1990"/><ref name="Johnson, R. W 1994"/> Gidgee (''A. cambagei'') replaces brigalow as rainfall drops in western regions and extends from {{cvt|650|to|300|mm}}.<ref>Weston, E. J. (1988). The Queensland Environment. Native pastures in Queensland their resources and management. W. H. Burrows, J. C. Scanlan and M. T. Rutherford. Brisbane, Queensland Government Press.</ref> Gidgee, with a maximum height of approximately {{cvt|12|m}}, is somewhat smaller than brigalow, which can attain heights of {{cvt|20|m}}.<ref>Anderson, E. R. (1993). Plants of Central Queensland. Brisbane, Queensland Government Press.</ref> In the north-western regions black gidgee (''A. argyrodendron'') replaces brigalow in many areas, while in Central-Western districts boree (''A. tephrina'') forms woodlands and shrublands, frequently on cracking clay soils and often in association with ''A. cambagei''. Georgina gidgee (''A. georginae'') woodlands are found in more arid regions in the {{cvt|200|to|250|mm}} rainfall belt.<ref name="Johnson, R. W 1994"/>
In New South Wales it is found from around [[Roto, New South Wales|Roto]] in the south to around [[Hungerford, New South Wales|Hungerford]] in the west and [[Willow Tree, New South Wales|Willow Tree]] in the east along the [[Great Dividing Range]].<ref name=nsw/> In Queensland it is found as far north as [[Townsville, Queensland|Townsville]].<ref name="RFK">{{cite web |author1=F.A.Zich |author2=B.P.M.Hyland |author3=T.Whiffen |author4=R.A.Kerrigan |author2-link=Bernard Hyland |year=2020 |url=https://apps.lucidcentral.org/rainforest/text/entities/Acacia_harpophylla.htm |title=''Acacia harpophylla'' |website=[[Australian Tropical Rainforest Plants]] Edition 8 (RFK8) |publisher=Centre for Australian National Biodiversity Research (CANBR), [[Australian Government]] |access-date=24 June 2021}}</ref>
==Response to fire== Species associated with these brigalow communities generally have a good capacity for re-sprouting following fire, and brigalow itself sprouts freely from the butt, roots and living stems in response to fire damage. Both gidgee and blackwood, in contrast, have a limited capacity to resprout following fire damage.<ref name="Anderson, E 1990"/><ref name="Johnson, R. W 1994"/> A notable exception to the fire tolerance of brigalow communities occurs in what are referred to as softwood scrubs, which are dense communities of brigalow and a range of particularly fire-sensitive species.<ref>Flannery, T. (1994). The future eaters. Frenchs Forest, Australia., Reed New Holland.</ref> Fire in any brigalow or gidgee woodland would be a rare event under natural circumstances, since pasture is at best sparse in these communities, consisting of ''[[Chloris (plant)|Chloris]]'', ''[[Setaria]]'' (syn. ''Paspalidium''), ''[[Dicanthium]]'', ''[[Sporobolus]]'' and ''[[Eragrostis]]'' species.<ref>Weston, E. J. (1988). Native Pasture Communities. Native pastures in Queensland their resources and management. W. H. Burrows, J. C. Scanlan and M. T. Rutherford. Brisbane, Department of Primary Industries.</ref>
== Large-scale land clearing == In 1962, the Fitzroy Basin Land Development Scheme, also known as the Brigalow Land Development scheme was enacted to rapidly clear vast expanses of dominant and co-dominant brigalow ecosystems to make way for agricultural cropping and grazing in brigalow bioregions of [[Queensland]]. 4.5Mha was cleared which accounted for 21% of all brigalow vegetation in Australia. This scheme caused major runoff into catchments. <ref>{{cite journal |last1=Thornton |first1=C.M |last2=Cowie |first2=B. A |last3=Freebairn |first3=D. M |last4=Playford |first4=C. L |title=The Brigalow Catchment Study: II∗. Clearing brigalow (''Acacia harpophylla'') for cropping or pasture increases runoff |journal=Australian Journal of Soil Research |date=2007 |volume=45 |pages=496-511 |doi=10.1071/SR07064 |url=https://era.dpi.qld.gov.au/id/eprint/11372/1/The%20Brigalow%20Catchment%20Study%20II.%20Clearing%20brigalow%20%28Acacia%20harpophylla%29%20for%20cropping%20or%20pasture%20increases%20runoff.pdf |access-date=15 November 2025}}</ref> Only 10% of this vegetation remains today (less than {{cvt|1000|km2}}) with clearing still continuing at a lesser extent. Brigalow vegetation groups are eligible to be listed as "endangered" under the Australian Government [[Environment Protection and Biodiversity Conservation Act 1999]]. The current main threats are continued land clearing for cropping and pasture.<ref>{{cite web |title=Brigalow (''Acacia harpophylla'' dominant and co-dominant) |url=https://www.dcceew.gov.au/environment/biodiversity/threatened/assessments/acacia-harpophylla#:~:text=The%20ecological%20community%20Brigalow%20(Acacia,as%20Endangered%20under%20this%20criterion. |website=DCCEEW |publisher=Australian Government |access-date=15 November 2025}}</ref>
==See also== {{Commons cat}} [[List of Acacia species|List of ''Acacia'' species]]
==References== {{Reflist}}
{{Taxonbar|from=Q2707674}}
[[Category:Acacia|harpophylla]] [[Category:Flora of Queensland]] [[Category:Endemic flora of Australia]] [[Category:Flora of New South Wales]] [[Category:Fabales of Australia]] [[Category:Drought-tolerant trees]] [[Category:Trees of Australia]] [[Category:Bushfood]] [[Category:Plants described in 1864]] [[Category:Taxa named by George Bentham]]