Banksia brownii
4421383
225502360
2008-07-14T01:04:15Z
Hesperian
111359
convert taxobox to APG-II using [[Project:AutoWikiBrowser|AWB]]
{{Taxobox
| name = Feather-leaved Banksia
| status = EN
| status_system = EPBC
| status_ref = <ref name="SPRAT" />
| image = Banksia brownii shrubby cropped.jpg
| image_caption = [[inflorescence]]s and leaves.
| regnum = [[Plant]]ae
| divisio = [[Angiospermae]]
| unranked_classis = [[Eudicots]]
| ordo = [[Proteales]]
| familia = [[Proteaceae]]
| genus = ''[[Banksia]]''
| species = '''''B. brownii'''''
| binomial = ''Banksia brownii''
| binomial_authority = [[William Baxter (botanist)|Baxter]] ex [[Robert Brown (botanist)|R.Br.]]
}}
'''''Banksia brownii''''', commonly known as '''Feather-leaved Banksia''' or '''Brown's Banksia''', is a [[species]] of [[shrub]] that occurs in [[Southwest Australia|southwest]] [[Western Australia]]. An attractive plant with fine feathery [[leaf|leaves]] and large red-brown flower spikes, it usually grows as an upright bush around two metres (7 ft) high, but can also occur as a small tree or a low spreading shrub. First collected in 1829 and published the following year, it is placed in ''[[Banksia]]'' [[Banksia subg. Banksia|subgenus ''Banksia'']], [[Banksia sect. Oncostylis|section ''Oncostylis'']], [[Banksia ser. Spicigerae|series ''Spicigerae'']]. There are two genetically distinct forms.
''B. brownii'' occurs naturally only in two population clusters between [[Albany, Western Australia|Albany]] and the [[Stirling Range]] in southwest Western Australia. In the Stirling Range it occurs among [[heath]] on rocky mountain slopes; further south it occurs among [[Jarrah]] [[woodland]] in shallow nutrient-poor sand. It is [[rare species|rare]] and [[endangered species|endangered]] in its natural [[habitat (ecology)|habitat]], with all major populations currently threatened by [[Phytophthora cinnamomi|''Phytophthora cinnamomi'' dieback]], a disease to which the species is highly susceptible. Other threats include loss of habitat, commercial exploitation and changes to the fire regime.
Highly valued by [[Australia]]'s [[horticulture|horticultural]] and [[floristry|cut flower]] industries, ''B. brownii'' is widely cultivated in areas not exposed to dieback. It prefers a sheltered position in soil with good drainage, and must be provided with some moisture over summer.
==Description==
''B. brownii'' usually grows as an upright bush between one and three metres (3–10 ft) high, but it can also grow as an openly branched small tree to six metres (20 ft) in sheltered [[gully|gullies]], or as a low, spreading shrub in exposed locations such as the peaks of the Stirling Range. The bark is a grey-brown colour, smooth and thin, with [[lenticel]]s. The leaves are long and thin, from three to ten centimetres (1–5 in) long, and five to ten millimetres ({{Fraction|3|16}}–{{Fraction|3|8}} in) wide. Dark green and hairless above but with a hairy white underside, they are easily recognised by their feather-like appearance, caused by the fact that they are finely divided almost back to the [[midrib]], into as many as 70 thin tapered lobes.<ref name="George 1981">{{The genus Banksia L.f. (Proteaceae)}}</ref><ref name="George 1999">{{cite encyclopedia | author = [[Alex George|George, Alex S.]] | year = 1999 | title = ''Banksia'' | editor = Wilson, Annette | encyclopedia = [[Flora of Australia (series)|Flora of Australia]] | volume = Volume 17B: Proteaceae 3: Hakea to Dryandra | pages = 175–251 | publisher = [[CSIRO Publishing]] / [[Australian Biological Resources Study]] | id = ISBN 0-643-06454-0}}</ref>
Flowers occur in typical ''Banksia'' "flower spikes", [[inflorescence]]s made up of hundreds of pairs of flowers densely packed in a [[helix|spiral]] around a woody axis. ''B. brownii''<nowiki>'</nowiki>s flower spike is a metallic red-brown colour, roughly cylindrical, 6 to 19 centimetres (2–7½ in) high and eight to ten centimetres (3–4 in) wide. Each flower consists of a tubular [[perianth]] made up of four united [[tepal]]s, and one long wiry [[carpel|style]]. Perianths are cream at the base and grey-brown at the end. Styles are rusty red-brown with a cream tip, and downwardly hooked rather than straight. The style end is initially trapped inside the upper perianth parts, but breaks free at [[anthesis]].<ref name="George 1981"/><ref name="George 1999"/>
Flower spikes are held erect and are typically terminal on a branch; often other branchlets grow up and around a spike from below. The fruiting structure is a stout woody "cone", around five centimetres (2 inches) in diameter, with a hairy appearance caused by the persistence of old withered flower parts. A "cone" may be embedded with up to 60 [[follicle (fruit)|follicles]],<ref name="George 1981"/> although usually there are very few or even none at all.<ref name="Day 1997">{{cite journal | author = Day, Denise A., Brian G. Collins and Rosemarie G. Rees | year = 1997 | title = Reproductive biology of the rare and endangered ''Banksia brownii'' Baxter ex R. Br. (Proteaceae) | journal = [[Australian Journal of Ecology]] | volume = 22 | pages = 307–315 | doi = 10.1111/j.1442-9993.1997.tb00676.x}}</ref> Unusually for ''Banksia'', each follicle contains just one seed.<ref name="Cochrane 2005">{{cite journal | author = Cochrane, Anne, Sarah Barrett and Sandra Gilfillan | year = 2005 | title = The feather-leaved banksia | journal = [[Landscope]] | volume = 20 | issue = 3 | pages = 22–28|id={{ISSN|0815-4465}}}}</ref> This is shiny black, [[oval (geometry)|oval]] in shape, about 20 millimetres (¾ in) long, with a brown papery wing.<ref name="George 1981"/><ref name="George 1999"/>
==Taxonomy==
[[Image:Banksia brownii leaf variations2.jpg|thumb|right|Leaf variation in ''B. brownii''. Left: a leaf of the shrubby "mountain form". Right: a leaf of the upright "Millbrook Road" form.]]
{{see also|Taxonomy of Banksia}}
''Banksia brownii'' was first collected near [[King George Sound]] in 1829 by [[William Baxter (botanist)|William Baxter]], who named it in honour of botanist [[Robert Brown (botanist)|Robert Brown]]. A formal description was published by Brown in his 1830 ''[[Supplementum Primum Prodromi Florae Novae Hollandiae]]'';<ref name="Brown 1830">{{cite book | author = [[Robert Brown (botanist)|Brown, Robert]] | year = 1830 | title = [[Supplementum Primum Prodromi Florae Novae Hollandiae]] | location = London | publisher = Richard Taylor}}</ref> thus the full [[botanic name]] of the species is ''Banksia brownii'' Baxter ex R.Br.<ref name="APNI">{{APNI | name = ''Banksia brownii'' Baxter ex R.Br. | id = 52959}}</ref> Under [[Brown's taxonomic arrangement of Banksia|Brown's taxonomic arrangement]], ''B. brownii'' was placed in subgenus ''[[Banksia verae]]'', the "True Banksias", because its inflorescence is a typical ''Banksia'' flower spike. ''Banksia verae'' was renamed ''[[Eubanksia]]'' by [[Stephan Ladislaus Endlicher|Stephan Endlicher]] in 1847.
[[Carl Meissner]] demoted ''Eubanksia'' to sectional rank in [[Meissner's taxonomic arrangement of Banksia|his 1856 classification]], and divided it into four series, with ''B. brownii'' placed in series ''[[Banksia ser. Dryandroideae|Dryandroideae]]''.<ref name="Meissner 1856">{{cite book | author = [[Carl Meissner|Meissner, Carl]] | year = 1856 | chapter = Proteaceae | editor = [[A. P. de Candolle]] | title = Prodromus systematis naturalis regni vegetabilis, pars decima quarta | url = http://www.botanicus.org/title.asp?barcode=31753003013338 | location = Paris | publisher = Sumptibus Victoris Masson}}</ref> When [[George Bentham]] published [[Bentham's taxonomic arrangement of Banksia|his 1870 arrangement]] in ''[[Flora Australiensis]]'', he discarded Meissner's series, placing all the species with hooked styles together in a section that he named ''[[Banksia sect. Oncostylis|Oncostylis]]''.<ref name="Bentham 1870">{{cite encyclopedia | author = [[George Bentham|Bentham, George]] | year = 1870 | title = ''Banksia'' | encyclopedia = [[Flora Australiensis|Flora Australiensis: A Description of the Plants of the Australian Territory]] | volume = Volume 5: Myoporineae to Proteaceae | pages = 541–562 | location = London | publisher = L. Reeve & Co.}}</ref> This arrangement would stand for over a century.
In 1891, [[Otto Kuntze]] challenged the generic name ''Banksia'' [[Carolus Linnaeus the Younger|L.f.]], on the grounds that the name ''Banksia'' had previously been published in 1775 as ''Banksia'' [[Johann Reinhold Forster|J.R.Forst]] & [[Georg Forster|G.Forst]], referring to the genus now known as ''[[Pimelea]]''. Kuntze proposed ''Sirmuellera'' as an alternative, republishing ''B. brownii'' as "''Sirmuellera brownei'' (Baxter)" [sic]. The challenge failed, ''Banksia'' L.f. was formally conserved, and ''Sirmuellera brownii'' (Baxter ex R.Br.) Kuntze" is now a [[synonym (botany)|nomenclatural synonym]] of ''B. brownii''.<ref name="George 1981"/>
[[Alex George]] published a new taxonomic arrangement of ''Banksia'' in his landmark 1981 monograph ''[[The genus Banksia L.f. (Proteaceae)]]''. Endlicher's ''Eubanksia'' became [[Banksia subg. Banksia|''B.'' subg. ''Banksia'']], and was divided into three sections, one of which was ''Oncostylis''. ''Oncostylis'' was further divided into four series, with ''B. brownii'' placed in series [[Banksia ser. Spicigerae|''Spicigerae'']] because its inflorescences are cylindrical.<ref name="George 1999"/>
In 1996, [[Kevin Thiele]] and Pauline Ladiges published a new arrangement for the genus, after [[cladistics|cladistic]] analyses yielded a [[cladogram]] significantly different from George's arrangement. [[Thiele and Ladiges' taxonomic arrangement of Banksia|Thiele and Ladiges' arrangement]] retained ''B. brownii'' in series ''Spicigerae'', placing it in ''B.'' subser. ''Occidentales'' along with ''[[Banksia occidentalis|B. occidentalis]]'' (Red Swamp Banksia), ''[[Banksia seminuda|B. seminuda]]'' (River Banksia), ''[[Banksia verticillata|B. verticillata]]'' (Granite Banksia) and ''[[Banksia littoralis|B. littoralis]]'' (Swamp Banksia).<ref name="Thiele 1996">{{cite journal | author = [[Kevin Thiele|Thiele, Kevin]] and Pauline Y. Ladiges | year = 1996 | title = A cladistic analysis of ''Banksia'' (Proteaceae) | journal = [[Australian Systematic Botany]] | volume = 9 | issue = 5 | pages = 661–733 | doi = 10.1071/SB9960661}}</ref> This arrangement stood until 1999, when George effectively reverted to his 1981 arrangement in his monograph for the ''[[Flora of Australia (series)|Flora of Australia]]'' series.
Under [[George's taxonomic arrangement of Banksia|George's taxonomic arrangement of ''Banksia'']], ''B. brownii''<nowiki>'</nowiki>s taxonomic placement may be summarised as follows:<ref name="George 1999"/>
:'''Genus ''[[Banksia]]'''''
::'''Subgenus ''[[Banksia subg. Banksia|Banksia]]'''''
:::Section ''[[Banksia sect. Banksia|Banksia]]''
:::Section ''[[Banksia coccinea|Coccinea]]''
:::'''Section ''[[Banksia sect. Oncostylis|Oncostylis]]'''''
::::'''Series ''[[Banksia ser. Spicigerae|Spicigerae]]'''''
:::::''[[Banksia spinulosa|B. spinulosa]]'' - ''[[Banksia ericifolia|B. ericifolia]]'' - ''[[Banksia verticillata|B. verticillata]]'' - ''[[Banksia seminuda|B. seminuda]]'' - ''[[Banksia littoralis|B. littoralis]]'' - ''[[Banksia occidentalis|B. occidentalis]]'' - '''''B. brownii'''''
::::Series ''[[Banksia tricuspis|Tricuspidae]]''
::::Series ''[[Banksia dryandroides|Dryandroidae]]''
::::Series ''[[Banksia ser. Abietinae|Abietinae]]''
::Subgenus ''[[Banksia subg. Isostylis|Isostylis]]''
''B. brownii''<span/>'s closest relative is held to be ''B. occidentalis'', which differs from ''B. brownii'' in having smaller, deep red flowers and narrow, sparsely serrate leaves.<ref name="George 1987">{{The Banksia Book}}</ref>
Since 1998, [[Austin Mast]] has been publishing results of ongoing cladistic analyses of [[DNA sequence]] data for the subtribe [[Banksiinae]], which is comprised of ''Banksia'' and ''[[Dryandra]]''. With respect to ''B. brownii'', Mast's results are somewhat at odds with those of both George and Thiele and Ladiges, finding it to be more closely related to ''[[Banksia nutans|B. nutans]]'' (Nodding Banksia) and ''[[Banksia quercifolia|B. quercifolia]]'' (Oak-leaved Banksia) than to many of the ''Spicigerae''. Overall, the inferred [[phylogeny]] is very greatly different from George's arrangement, and provides compelling evidence for the [[paraphyly]] of ''Banksia'' with respect to ''Dryandra''.<ref name="Mast 1998">{{cite journal | author = [[Austin Mast|Mast, A. R.]] | year = 1998 | title = Molecular systematics of subtribe Banksiinae (''Banksia'' and ''Dryandra''; Proteaceae) based on cpDNA and nrDNA sequence data: implications for taxonomy and biogeography | journal = [[Australian Systematic Botany]] | volume = 11 | pages = 321–342 | doi = 10.1071/SB97026}}</ref><ref name="Mast 2002">{{cite journal | author = [[Austin Mast|Mast, Austin]] and Thomas J. Givnish | year = 2002 | title = Historical biogeography and the origin of stomatal distributions in ''Banksia'' and ''Dryandra'' (Proteaceae) based on Their cpDNA phylogeny | journal = [[American Journal of Botany]] | volume = 89 | issue = 8 | pages = 1311–1323 | id = {{ISSN|0002-9122}} | url = http://www.amjbot.org/cgi/content/full/89/8/1311 | accessdate=2006-07-02 | doi = 10.3732/ajb.89.8.1311}}</ref><ref name="Mast 2005">{{cite journal | author = [[Austin Mast|Mast, Austin R.]], Eric H. Jones and Shawn P. Havery | year = 2005 | volume = 18 | issue = 1 | title = An assessment of old and new DNA sequence evidence for the paraphyly of ''Banksia'' with respect to ''Dryandra'' (Proteaceae) | journal = [[Australian Systematic Botany]] | pages = 75–88 | publisher = CSIRO Publishing / Australian Systematic Botany Society | doi = 10.1071/SB04015}}</ref> Early in 2007, Mast and Thiele initiated a rearrangement of ''Banksia'' by transferring ''Dryandra'' into it, and publishing [[Banksia subg. Spathulatae|''B.'' subg. ''Spathulatae'']] for the species having spoon-shaped [[cotyledon]]s. They foreshadowed publishing a full arrangement once DNA sampling of ''Dryandra'' was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then ''B. brownii'' is placed in ''B.'' subg. ''Spathulatae''.<ref name="Mast 2007">{{cite journal | author = [[Austin Mast|Mast, Austin R.]] and [[Kevin Thiele]] | year = 2007 | title = The transfer of ''Dryandra'' R.Br. to ''Banksia'' L.f. (Proteaceae) | journal = [[Australian Systematic Botany]] | volume = 20 | pages = 63–71 | doi = 10.1071/SB06016}}</ref>
Two genetically distinct forms of ''B. brownii'' are recognised: a "mountain form" with a shrubby habit, short thin hard leaves, and a squat inflorescence; and a "Millbrook Road form", with a tree habit and longer, wider, soft leaves.<ref name="Keighery 1988">{{cite journal | author = Keighery, Greg | year = 1988 | title = Endangered! Brown's Banksia (Banksia brownii) | journal = [[Landscope]] | volume = 3 | issue = 4 | pages = 54}}</ref><ref name="SPRAT">{{cite web | title = Banksia brownii: Brown's Banksia, Feather-leaved Banksia | url = http://www.deh.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=8277 | work = Species Profile and Threats Database | publisher = [[Department of the Environment and Water Resources]] | accessdate = 2006-07-10}}</ref> These forms currently have no taxonomic status, but genetic testing is planned to determine whether they constitute two subspecies.<ref name="Cochrane 2005"/> Some horticulturists also recognise an intermediate form that may not breed true from seed.<ref name="BSGN 2003">{{cite journal | author = Liber, Cas (ed.) | year = 2003 | title = Threatened Banksia's #2: Banksia brownii | journal = Banksia Study Group Newsletter | volume = 5 | issue = 1 | pages = 1–2 | url = http://asgap.org.au/banksSG/banksiasg-5-1.pdf | format = PDF | accessdate = 2006-07-11}}</ref>
==Distribution and habitat==
[[Image:B brownii dist map.png|right|thumb|Distribution of ''B. brownii'' within Australia]]
''B. brownii'' occurs between Albany and the Stirling Range in the [[Southwest Australia|southwest]] of Western Australia,<ref name="Taylor 1988">{{The Banksia Atlas}}</ref> at the juncture of the [[Esperance Plains]], [[Warren (biogeographic region)|Warren]] and [[Jarrah Forest]] [[biogeography|biogeographic]] regions. This is the taxonomically richest area for ''Banksia'', with 19 species, of which six are [[endemic (ecology)|endemic]], including ''B. brownii'' itself. It is cool and wet, with temperatures between four and 30 °C (39–86 °F) and rainfall of around 800 millimetres (31 in).<ref name="Lamont 1996">{{cite journal | author = [[Byron Lamont|Lamont, Byron B.]] and S. W. Connell | year = 1996 | title = Biogeography of Banksia in southwestern Australia | journal = [[Journal of Biogeography]] | volume = 23 | issue = 3 | pages = 295–309 | doi = 10.1046/j.1365-2699.1996.00027.x}}</ref> The species occurs there in two distinct population clusters: southern populations occur among low woodland of ''[[Eucalyptus marginata]]'' (Jarrah) in shallow, nutrient-poor white or grey sand over [[laterite]];<ref name="Leigh 1992">{{cite book | author = Leigh, J. H. and J. D. Briggs (eds) | year = 1992 | title = Threatened Australian Plants: Overview and Case Studies | publisher = Australian National Parks and Wildlife Service | location = Canberra | id = ISBN 0-642-14203-3}}</ref> Stirling Range populations occur at altitudes of between 500 and 1100 metres (1640–3960 ft), among [[heath (habitat)|heath]] on rocky mountain slopes and tops, and in [[shale]] in gullies.<ref name="Taylor 1988"/><ref name="Leigh 1992"/>
There are 27 known populations within this region, but only nine of these populations contain more than 10 individual plants, and only five populations have more than 100. Ten populations are now presumed extinct.<ref name="Shearer 2007">{{cite journal | author = Shearer, B. L.; Crane, C. E.; Barrett, S.; Cochrane, A. | year = 2007 | title = ''Phytophthora cinnamomi'' invasion, a major threatening process to conservation of flora diversity in the South-west Botanical Province of Western Australia | journal = Australian Journal of Botany | volume = 55 | pages = 225–238 | doi = 10.1071/BT06019}}</ref> The total number of plants is estimated at around 1000.<ref name="Lamont 2007">{{cite journal | author = Lamont, Byron B.; Enright, Neal J.; Witkowski, E. T. F.; Groeneveld, J. | year = 2007 | title = Conservation biology of banksias: insights from natural history to simulation modelling | journal = Australian Journal of Botany | volume = 55 | pages = 280–292 | doi = 10.1071/BT06024}}</ref>
==Ecology==
{{see also|Ecology of Banksia}}
Coastal plants begin to flower at around five years from seed, but plants in the Stirling Range take much longer to mature.<ref name="Day 1997"/> In one Stirling Range population, only 15% of plants had flowered after eight years.<ref name="Cochrane 2005"/> Flowering time is highly variable, but in general it occurs between March and August, with a peak around June. More flowers open during the day than at night.<ref name="Day 1997"/>
As with other ''Banksia'' species, ''B. brownii'' is a heavy producer of [[nectar (plant)|nectar]], and serves as a food source for a range of nectariferous birds, mammals and insects. Honeyeaters such as the [[New Holland Honeyeater]], [[Western Spinebill]] and [[Red Wattlebird]] are frequent visitors that often carry heavy [[pollen]] loads, making them important pollinators. Nocturnal mammals such as [[Bush Rat]]s and [[Honey Possum]]s also carry heavy pollen loads, but the foraging behaviour of Bush Rats suggests that these may transfer pollen only over very short distances. Invertebrate visitors include the introduced [[western honeybee|Western Honeybee]], [[Stingless bee#Stingless bees of Australia|native bees]], [[fly|flies]] and [[ant]]s; bees appear to be effective pollinators, but ants and flies forage only at the base of flowers and do not come in contact with plant pollen.<ref name="Day 1997"/>
The species is partly [[self-pollination|self-compatible]], as some seed is set when pollinators are excluded. Selection against self-pollinated seed has been observed,<ref name="Sampson 1996">{{cite book | author = Sampson, J. F., D. J. Coates and S. J. van Leeuwen | year = 1996 | chapter = Mating system variation in animal-pollinated rare and endangered plant populations in Western Australia | editor = [[Stephen Hopper|S. D. Hopper]], M. Harvey, J. Chappill and [[Alex George|A. S. George]] (eds) | title = Gondwanan Heritage: Past, Present and Future of the Western Australian Biota | pages = 292–298 | publisher = Surrey Beatty | location = Chipping Norton | id = ISBN 0-949324-66-3}}</ref> but the species has nonetheless been shown to have one of the lowest [[outcrossing]] rates of any ''Banksia''.<ref name="Sampson 1994">{{cite journal | author = Sampson, J. F., B. G. Collins and D. J. Coates | year = 1994 | title = Mixed Mating in Banksia brownii Baxter ex R. Br. (Proteaceae) | journal = [[Australian Journal of Botany]] | volume = 42 | pages = 103–111 | doi = 10.1071/BT9940103}}</ref> This is probably caused by the small population sizes, which increase the probability of self-fertilisation, and may discourage visits by pollinators.<ref name="Goldingay 1998">{{cite journal | author = Goldingay, Ross L. and Susan M. Carthew | year = 1998 | title = Breeding and Mating Systems of Australian Proteaceae | journal = [[Australian Journal of Botany]] | volume = 46 | issue = 4 | pages = 421–437 | doi = 10.1071/BT97037}}</ref>
It has a low rate of fruiting, with less than 1% of flowers developing into follicles, and more than half of the inflorescences failing to form any follicles at all.<ref name=Collins 1996">{{cite book | author = Collins, B. G., S. McDavitt and J. F. Sampson | year = 1996 | chapter = Flowering phenology and fecundity of Banksia brownii Baxter ex R.Br. (Proteaceae) | editor = [[Stephen Hopper|S. D. Hopper]], M. Harvey, J. Chappill and [[Alex George|A. S. George]] (eds) | title = Gondwanan Heritage: Past, Present and Future of the Western Australian Biota | pages = 292–298 | publisher = Surrey Beatty | location = Chipping Norton | id = ISBN 0-949324-66-3}}</ref> Seed survival rates are similarly low. More than half of a plant's seed crop may be lost to the [[larva]]e of [[moth]]s and [[weevil]]s, which burrow into the cobs to eat the seeds and [[pupa]]te in the follicles; and further seed losses are caused by [[granivore|granivorous]] birds such as [[cockatoo]]s, which break off the cobs to eat both the seeds and the insect larvae.<ref name="Day 1997"/>
A small proportion of follicles open and release their seed spontaneously, but most remain closed until stimulated to open by [[bushfire]]. Bushfire kills the maternal plant, which has neither thick bark nor [[lignotuber]]s, but the subsequent shedding of seed allows the population to regenerate.<ref name="SPRAT"/> Seed predation continues after its release: in one study, ''B. brownii'' seeds were placed on the ground in both burnt and unburnt sides; almost all were eaten by parrots within four weeks.<ref name="Lamont 2007"/>
==Conservation==
Threats to ''B. brownii'' include loss of habitat due to land clearing, commercial exploitation, disease, and changes to the fire regime. The fragmentation of populations is also of concern, as it causes the genetic diversity of the species to decline, potentially reducing [[heterosis|vigour]].<ref name="Cochrane 2005"/>
The species is currently listed as "[[List of endangered Australian plants|Endangered]]" under Australia's [[Environment Protection and Biodiversity Conservation Act 1999]],<ref name="Brown 1998">{{cite book|author=Brown, Andrew, Carolyn Thomson-Dans and Neville Marchant (eds)|year=1998|title=Western Australia's Threatened Flora|location=Como, Western Australia|publisher=[[Department of Conservation and Land Management]]|id=ISBN 0-7309-6875-8}}</ref> and "Rare" under Western Australia's [[Wildlife Conservation Act 1950]].<ref name="Gazette 2006">{{cite web | date = [[2006-06-23]] | title = Wildlife Conservation (Rare Flora) Notice 2006 | work = Government Gazette, WA | pages = 2169–2174 | url = http://www.naturebase.net/dmdocuments/flora_notice_2006_gazette.pdf | format = PDF | accessdate = 2006-07-11}}</ref> These [[statute|acts]] provide legislative protection against a range of potential threats, including commercial harvesting of flowers and land clearing. Further protection is afforded to northern populations by the fact that they occur within the [[Stirling Range National Park]]. Despite these measures, recent population [[extinction]]s and a projected decline of more than 80% within three generations has seen calls for the species to be upgraded to [[critically endangered]].<ref name="Cochrane 2005"/> It is thought that without protective measures in place, ''B. brownii'' would be extinct within a decade;<ref name="Brown 1998"/> and that extinction would be "not only a tragedy in itself but may have unforeseen, and potentially disastrous, consequences for the functioning of the vegetation communities of which feather-leaved banksia is an integral part."<ref name="Cochrane 2005"/>
===Disease===
The main threat to ''B. brownii'' is dieback caused by the [[introduced species|introduced]] plant [[pathogen]] ''P. cinnamomi'', a soil-borne [[water mould]] that causes root rot. Studies of the effect of ''P. cinnamomi'' on ''B. brownii'' have found it to be "highly susceptible" to dieback, with specimens "frequently and consistently killed in the wild".<ref name="DEH">{{cite web | url = http://www.environment.gov.au/biodiversity/invasive/publications/p-cinnamomi/pubs/appendix4.pdf | title = Part 2, Appendix 4: The responses of native Australian plant species to Phytophthora cinnamomi | work = [http://www.environment.gov.au/biodiversity/invasive/publications/p-cinnamomi/ Management of Phytophthora cinnamomi for Biodiversity Conservation in Australia] | publisher = [[Department of the Environment and Heritage]], Australian Government | year = 2006 | accessdate = 2007-04-30}}</ref> As of 2007, all major populations of ''B. brownii'', and all but one minor population, are suffering from dieback.<ref name="Shearer 2007"/> Moreover, all populations are in an area vulnerable to dieback, so even the uninfected population is considered under threat. According to [[Byron Lamont]], "the demise of this species in the wild appears imminent."<ref name="Lamont 2007"/>
No recovery plan has been put in place; instead the species is managed as part of a broader response to the region's dieback [[epidemic]].<ref name="EA 2001">{{cite web | publisher = [[Environment Australia]] | title = Threat Abatement Plan for Dieback Caused by the Root-rot Fungus Phytophthora cinnamomi | url = http://www.environment.gov.au/biodiversity/threatened/publications/tap/phytophthora/index.html | year = 2001 | accessdate = 2007-04-30}}</ref> A number of protective measures have been implemented, including site access restrictions, the collection and cold-storage of seed, and the treatment of plants with [[phosphite]]. Phosphite boosts the resistance of both infected and uninfected plants, and also acts as a direct [[fungicide]]. Aerial spraying of phosphite boosts plant survival and slows the spread of infection,<ref name="Cochrane 2005"/><ref name="Barrett 2003">{{cite journal | author = Barrett, S. R., B. L. Shearer and G. E. St G. Hardy | year = 2003 | title = The efficacy of phosphite applied after inoculation on the colonisation of ''Banksia brownii'' stems by ''Phytophthora cinnamomi'' | journal = [[Australasian Plant Pathology]] | volume = 32 | pages = 1–7 | doi = 10.1071/AP02061}}</ref> but must be carefully managed as studies have shown that [[foliar spraying]] of phosphite adversely affects root and shoot growth.<ref name="Barrett 2002">{{cite journal | author = Barrett, S. R., B. L. Shearer and G. E. St J. Hardy | year = 2002 | title = Root and shoot development in Corymbia calophylla and Banksia brownii after the application of the fungicide phosphite | journal = [[Australian Journal of Botany]] | volume = 50 | issue = 2 | doi = 10.1071/BT01018}}</ref> Direct injection of phosphite into the [[Plant stem|stem]] of each tree appears to lack this disadvantage, but is costly to administer and restricted to known plants.
Other diseases to which ''B. brownii'' is vulnerable include the parasitic fungus ''[[Armillaria luteobubalina]]''<ref name="Wills 1994">{{cite journal | author = Wills, R. T. and G. J. Keighery | year = 1994 | title = Ecological impact of plant disease on plant communities | journal = [[Journal of the Royal Society of Western Australia]] | volume = 77 | issue = 4 | pages = 127–131}}</ref> and the aerial [[canker]] [[fungus]] ''[[Zythiostroma]]''.
===Fire regime===
Because ''B. brownii'' releases its seed in response to bushfire, it is important that fires occur at intervals that allow the plants to generate plenty of viable seed. The optimum fire interval is around 18 years.<ref name="Cochrane 2005"/> If fire occurs too frequently, plants are burned before reaching maturity or before they have produced sufficient seed to ensure regeneration of the population. This may cause populations to decline, or even local extinction. Too-infrequent fire also causes population decline, as more plants die of natural attrition without releasing their seed, resulting in seed wastage.<ref name="Lamont 1996">{{cite book | last = Lamont | first = Byron B. | year = 1996 | chapter = Conservation biology of banksias in southwestern Australia | editor = Stephen D. Hopper, M. Harvey, J. Chappill and A. S. George (eds) | title = Gondwanan Heritage: Past, Present and Future of the Western Australian Biota | pages = 292–298 | publisher = Surrey Beatty | location = Chipping Norton | id = ISBN 0-949324-66-3}}</ref>
==Cultivation==
[[Image:B brownii cutbloooms email.jpg|thumb|right|Cut flower spikes from ''Banksia brownii'']]
With large metallic red inflorescences and attractive feathery leaves that are perhaps the softest of all ''Banksia'' species,<ref name="George 1987"/> ''B. brownii'' is highly valued by Australia's horticultural and [[cut flower industry|cut flower industries]]. Seeds and plants are readily available in Australian nurseries, and it is widely cultivated in areas not exposed to dieback.<ref name="Keighery 1988"/><ref name="BSGN 2003"/> It prefers a sheltered position in soil with good drainage, and must be provided with moisture over summer. It grows quickly, but takes several years to flower. Once established, it is frost-tolerant and tolerates light pruning not below the green foliage. The flowers are attractive in late bud, but lose their colour as soon as they open. Because they are usually surrounded by branchlets, they may be partly hidden by foliage.<ref name="George 1987"/>
The main obstacle to cultivation is the species' extreme sensitivity to dieback, which is widespread in suburban gardens. However, the species has been successfully [[grafting|grafted]] onto a [[rootstock]] of ''[[Banksia integrifolia|B. integrifolia]]'' (Coast Banksia), which renders it hardy on a range of soils.<ref name=Dawson 1996">{{cite conference | author = Dawson, Iain | year = 1996 | title = Grafting Australian Native Plants | booktitle = Proceedings of the IV National Workshop for Australian Native Flowers | url = http://www.anbg.gov.au/hort.research/grafting.html | accessdate = 2006-06-29}}</ref>
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==References==
{{reflist|2}}
==External links==
{{commons|Banksia brownii}}
{{wikispecies|Banksia brownii}}
{{wikisourcepar|Flora Australiensis/Volume V/CIV. Proteaceae/28. Banksia#Banksia Brownii|Flora Australiensis/​Volume V/​CIV. Proteaceae/​28. Banksia#Banksia Brownii}}
*{{FloraBase | name = ''Banksia brownii'' R.Br. | id = 1806}}
*{{Flora of Australia Online | name = ''Banksia brownii'' Baxter ex R.Br. | id = 3471}}
*{{APNI | name = ''Banksia brownii'' Baxter ex R.Br | id = 52959}}
*{{SPRAT | name = ''Banksia brownii'' — Brown's Banksia, Feather-leaved Banksia | id = 8277}}
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[[Category:Banksia taxa by scientific name|Brownii]]
[[Category:Conservation in Western Australia]]
[[Category:Flora of Western Australia]]
[[Category:Plants and pollinators]]
[[Category:Endangered flora of Australia]]
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