Banksia brownii
Encyclopedia
Banksia brownii, commonly known as Feather-leaved Banksia or Brown's Banksia, is a species
of shrub
that occurs in southwest
Western Australia
. An attractive plant with fine feathery 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
subgenus Banksia
, section Oncostylis
, series Spicigerae
. There are two genetically distinct forms.
B. brownii occurs naturally only in two population clusters between 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
and endangered
in its natural habitat
, with all major populations currently threatened by 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 horticultural
and 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.
, 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 (– 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.
Flowers occur in typical Banksia "flower spikes", inflorescence
s made up of hundreds of pairs of flowers densely packed in a spiral
around a woody axis. B. brownii' 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 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
.
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 follicles
, although usually there are very few or even none at all. Unusually for Banksia, each follicle contains just one seed. This is shiny black, oval
in shape, about 20 millimetres (¾ in) long, with a brown papery wing.
in 1829 by William Baxter
, who named it in honour of botanist Robert Brown
. A formal description was published by Brown in his 1830 Supplementum Primum Prodromi Florae Novae Hollandiae
; thus the full botanic name of the species is Banksia brownii Baxter ex R.Br. Under 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 Endlicher
in 1847.
Carl Meissner
demoted Eubanksia to sectional rank in his 1856 classification
, and divided it into four series, with B. brownii placed in series Dryandroideae
. When George Bentham
published 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 Oncostylis
. This arrangement would stand for over a century.
In 1891, Otto Kuntze
challenged the generic name Banksia L.f.
, on the grounds that the name Banksia had previously been published in 1775 as Banksia J.R.Forst
& 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 nomenclatural synonym of B. brownii.
Alex George
published a new taxonomic arrangement of Banksia in his landmark 1981 monograph The genus Banksia L.f. (Proteaceae)
. Endlicher's Eubanksia became 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 Spicigerae
because its inflorescences are cylindrical.
In 1996, Kevin Thiele
and Pauline Ladiges published a new arrangement for the genus, after cladistic
analyses yielded a cladogram
significantly different from George's arrangement. Thiele and Ladiges' arrangement
retained B. brownii in series Spicigerae, placing it in B. subser. Occidentales along with B. occidentalis
(Red Swamp Banksia), B. seminuda
(River Banksia), B. verticillata
(Granite Banksia) and B. littoralis
(Swamp Banksia). This arrangement stood until 1999, when George effectively reverted to his 1981 arrangement in his monograph for the Flora of Australia
series.
Under George's taxonomic arrangement of Banksia
, B. brownii' s taxonomic placement may be summarised as follows:
Subgenus Isostylis
B. brownii'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.
Since 1998, Austin Mast
has been publishing results of ongoing cladistic analyses of DNA sequence
data for the subtribe Banksiinae, which comprises 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 B. nutans
(Nodding Banksia) and 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. Early in 2007, Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing 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.
Three genetically distinct forms of B. brownii are recognised: the better known forms are 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. Some horticulturists also recognise an intermediate form. Recent genetic testing has confirmed the existence of three distinct forms, but currently these have no taxonomic status.
(35°S) and the Stirling Range
(34°24'S) in the southwest
of Western Australia, at the juncture of the Esperance Plains
, Warren
and Jarrah Forest
biogeographic
regions. This is the taxonomically richest area for Banksia, with 19 species, of which six are 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). 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
; Stirling Range populations occur at altitudes of between 500 and 1100 metres (1640–3960 ft), among heath
on rocky mountain slopes and tops, and in shale
in gullies.
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. The total number of plants is estimated at around 1000.
As with other Banksia species, B. brownii is a heavy producer of nectar
, and serves as a food source for a range of nectariferous birds, mammals and insects. Honeyeaters such as Phylidonyris novaehollandiae (New Holland Honeyeater), Acanthorhynchus superciliosus (Western Spinebill) and Anthochaera carunculata (Red Wattlebird) are frequent visitors that often carry heavy pollen
loads, making them important pollinators. Nocturnal mammals such as Rattus fuscipes (Bush Rat) and Tarsipes rostratus (Honey Possum) 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 Apis mellifera (Western Honeybee), native bees, 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.
The species is partly self-compatible
, as some seed is set when pollinators are excluded. Selection against self-pollinated seed has been observed, but the species has nonetheless been shown to have one of the lowest outcrossing
rates of any Banksia. This is probably caused by the small population sizes, which increase the probability of self-fertilisation, and may discourage visits by pollinators.
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. 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 granivorous birds such as cockatoo
s, which break off the cobs to eat both the seeds and the insect larvae.
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. 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.
. Climate change
is also of concern: depending on the severity of change, the range of this species is predicted to contract by 30% to 50% by 2080.
B. brownii has been assessed as having a very high risk of extinction. It is estimated that without protective measures in place, it would be extinct within a decade; 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." The species has not yet been formally assessed for the IUCN Red List
, but warrants a "Critically Endangered (CR)" ranking because populations are projected to decline by more than 80% within the next three generations. It is currently listed as "Endangered" under Australia's Environment Protection and Biodiversity Conservation Act 1999
(EPBC Act), and "Rare" under Western Australia's Wildlife Conservation Act 1950
. These acts
provide legislative protection against a range of potential threats, including commercial harvesting of flowers and land clearing. Further statutory protection is afforded by the fact that populations occur within the Eastern Stirling Range Montane Heath and Thicket threatened ecological community
, which is listed as "Endangered" under the EPBC Act, and the Montane Mallee Thicket of the Stirling Range threatened ecology community, which has been assessed as "Endangered" by the Western Australian government; and by the presence of northern population within the Stirling Range National Park
.
A five-year interim management plan was put in place by the Western Australia's Department of Environment and Conservation in October 2005. Actions under that plan include regular monitoring of populations, management of the threats of fire and P. cinnamomi, and the cold storage of seed. As of December 2009 a recovery plan is being developed. There is also a translocation project underway.
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". As of 2007, all major populations of B. brownii, and all but one minor population, are suffering from dieback. 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."
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, but must be carefully managed as studies have shown that foliar spraying of phosphite adversely affects root and shoot growth. Direct injection of phosphite into the 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
and the aerial canker
fungus
Zythiostroma
.
's Millennium Seed Bank. This includes seed collected from populations that have since become extinct. In 2008, some of this seed was germinated, and seedlings were planted at a location near Albany. Genetic analysis of the seedlings revealed some genetic diversity that was not present in any extant population. The conservation of these seeds had thus preserved some of the species' genetic diversity that would otherwise have been lost through population extinction, providing a powerful example of the importance of seed banking to conservation efforts. A seed orchard was planted in 2007, and by 2010 this had yielded over 400 disease-free, healthy plants, some of which had grown more than three times the rate of those in the wild.
The main obstacle to cultivation is the species' extreme sensitivity to dieback, which is widespread in suburban gardens. However, the species has been successfully grafted
onto a rootstock
of B. integrifolia
(Coast Banksia), which renders it hardy on a range of soils.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
that occurs in southwest
Southwest Australia
Southwest Australia is a biodiversity hotspot that includes the Mediterranean forests, woodlands, and scrub ecoregions of Western Australia. The region has a wet-winter, dry-summer Mediterranean climate, one of five such regions in the world...
Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. An attractive plant with fine feathery leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
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
Banksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. When it comes to size, banksias range from prostrate woody shrubs to trees up...
subgenus Banksia
Banksia subg. Banksia
Banksia subg. Banksia is a valid botanic name for a subgenus of Banksia. As an autonym, it necessarily contains the type species of Banksia, B. serrata . Within this constraint, however, there have been various circumscriptions.-Banksia verae:B. subg...
, section Oncostylis
Banksia sect. Oncostylis
Banksia sect. Oncostylis is one of four sections of subgenus Banksia subg. Banksia. It contains those Banksia species with hooked pistils. All of the species in Oncostylis also exhibit a top-down sequence of flower anthesis, except for Banksia nutans which is bottom-up.Banksia sect...
, series Spicigerae
Banksia ser. Spicigerae
Banksia ser. Spicigerae is a taxonomic series in the genus Banksia. It consists of the seven species in section Oncostylis that have cylindrical inflorescences. These range in form from small shrubs to tall trees. The leaves grow in either an alternate or whorled pattern, with various shape forms...
. There are two genetically distinct forms.
B. brownii occurs naturally only in two population clusters between Albany
Albany, Western Australia
Albany is a port city in the Great Southern region of Western Australia, some 418 km SE of Perth, the state capital. As of 2009, Albany's population was estimated at 33,600, making it the 6th-largest city in the state....
and the Stirling Range
Stirling Range
The Stirling Range or Koikyennuruff is a range of mountains and hills in the Great Southern region of Western Australia, 337 km south-east of Perth. It is located at approximately and is over 60 km wide from west to east, stretching from the highway between Mount Barker and Cranbrook...
in southwest Western Australia. In the Stirling Range it occurs among heath
Heath (habitat)
A heath or heathland is a dwarf-shrub habitat found on mainly low quality acidic soils, characterised by open, low growing woody vegetation, often dominated by plants of the Ericaceae. There are some clear differences between heath and moorland...
on rocky mountain slopes; further south it occurs among Jarrah
Jarrah
Eucalyptus marginata is one of the most common species of Eucalyptus tree in the southwest of Western Australia. The tree and the wood are usually referred to by the Aboriginal name Jarrah...
woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
in shallow nutrient-poor sand. It is rare
Rare species
A rare species is a group of organisms that are very uncommon or scarce. This designation may be applied to either a plant or animal taxon, and may be distinct from the term "endangered" or "threatened species" but not "extinct"....
and endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
in its natural habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
, with all major populations currently threatened by Phytophthora cinnamomi dieback
Phytophthora cinnamomi
Phytophthora cinnamomi is a soil-borne water mould that produces an infection which causes a condition in plants called root rot or dieback. The plant pathogen is one of the world's most invasive species and is present in over 70 countries from around the world.- Life cycle and effects on plants :P...
, 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
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
's horticultural
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...
and cut flower
Floristry
Floristry is the general term used to describe production, commerce and trade in flowers. It encompasses flower care and handling, floral design or flower arranging, merchandising, and display and flower delivery. Wholesale florists sell bulk flowers and related supplies to professionals in the trade...
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 gulliesGully
A gully is a landform created by running water, eroding sharply into soil, typically on a hillside. Gullies resemble large ditches or small valleys, but are metres to tens of metres in depth and width...
, 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
Lenticel
A lenticel is an airy aggregation of cells within the structural surfaces of the stems, roots, and other parts of vascular plants. It functions as a pore, providing a medium for the direct exchange of gasses between the internal tissues and atmosphere, thereby bypassing the periderm, which would...
s. The leaves are long and thin, from three to ten centimetres (1–5 in) long, and five to ten millimetres (– 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.
Flowers occur in typical Banksia "flower spikes", inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s made up of hundreds of pairs of flowers densely packed in a spiral
Helix
A helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...
around a woody axis. B. brownii
Perianth
The term perianth has two similar but separate meanings in botany:* In flowering plants, the perianth are the outer, sterile whorls of a flower...
made up of four united tepal
Tepal
Tepals are elements of the perianth, or outer part of a flower, which include the petals or sepals. The term tepal is more often applied specifically when all segments of the perianth are of similar shape and color, or undifferentiated, which is called perigone...
s, and one long wiry 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
Anthesis
Anthesis is the period during which a flower is fully open and functional. It may also refer to the onset of that period.The onset of anthesis is spectacular in some species. In Banksia species, for example, anthesis involves the extension of the style far beyond the upper perianth parts...
.
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 follicles
Follicle (fruit)
In botany, a follicle is a dry unilocular many-seeded fruit formed from one carpel and dehiscing by the ventral suture in order to release seeds, such as in larkspur, magnolia, banksia, peony and milkweed....
, although usually there are very few or even none at all. Unusually for Banksia, each follicle contains just one seed. This is shiny black, oval
Oval (geometry)
In technical drawing, an oval is a figure constructed from two pairs of arcs, with two different radii . The arcs are joined at a point, in which lines tangential to both joining arcs lie on the same line, thus making the joint smooth...
in shape, about 20 millimetres (¾ in) long, with a brown papery wing.
Taxonomy
Banksia brownii was first collected near King George SoundKing George Sound
King George Sound is the name of a sound on the south coast of Western Australia. Located at , it is the site of the city of Albany.The sound covers an area of and varies in depth from to ....
in 1829 by William Baxter
William Baxter (botanist)
William Baxter was an English gardener who collected in Australia on behalf of English nurserymen and private individuals. He had developed his horticultural reputation as gardener to the Comtesse de Vandes in Bayswater, London, many of the plants he had nurtured being used for illustrations in...
, who named it in honour of botanist Robert Brown
Robert Brown (botanist)
Robert Brown was a Scottish botanist and palaeobotanist who made important contributions to botany largely through his pioneering use of the microscope...
. A formal description was published by Brown in his 1830 Supplementum Primum Prodromi Florae Novae Hollandiae
Supplementum Primum Prodromi Florae Novae Hollandiae
Supplementum primum Prodromi florae Novae Hollandiae is an 1830 supplement to Robert Brown's Prodromus florae Novae Hollandiae et Insulae Van Diemen. It may be referred to by its standard botanical abbreviation Suppl. Prodr. Fl. Nov...
; thus the full botanic name of the species is Banksia brownii Baxter ex R.Br. Under Brown's taxonomic arrangement
Brown's taxonomic arrangement of Banksia
Robert Brown's taxonomic arrangement of Banksia was published in his 1810 Prodromus Florae Novae Hollandiae et Insulae Van Diemen, and expanded in this 1830 supplement to that publication, Supplementum Primum Prodromi Florae Novae Hollandiae...
, 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 Endlicher
Stephan Ladislaus Endlicher
Stephan Ladislaus Endlicher was an Austrian botanist, numismatist and Sinologist. He was a director of the Botanical Garden of Vienna. He was born in Pressburg and died in Vienna....
in 1847.
Carl Meissner
Carl Meissner
Carl Daniel Friedrich Meissner was a Swiss botanist.Born in Bern, Switzerland on 1 November 1800, he was christened Meisner but later changed the spelling of his name to Meissner. For most of his 40 year career he was Professor of Botany at University of Basel...
demoted Eubanksia to sectional rank in his 1856 classification
Meissner's taxonomic arrangement of Banksia
Carl Meissner's taxonomic arrangement of Banksia was published in 1856, as part of his chapter on the Proteaceae in A. P. de Candolle's Prodromus systematis naturalis regni vegetabilis. It was the first attempt to provide an infrageneric classification for the genus, aside from Robert Brown's...
, and divided it into four series, with B. brownii placed in series Dryandroideae
Banksia ser. Dryandroideae
Banksia ser. Dryandroideae is a valid botanic name for a taxonomic series in the plant genus Banksia. First published by Carl Meissner in 1856, the name has had two circumscriptions. As presently circumscribed it is monotypic, containing only B. dryandroides.-According to Meissner:B. ser...
. When George Bentham
George Bentham
George Bentham CMG FRS was an English botanist, characterized by Duane Isely as "the premier systematic botanist of the nineteenth century".- Formative years :...
published his 1870 arrangement
Bentham's taxonomic arrangement of Banksia
George Bentham's taxonomic arrangement of Banksia was published in 1870, in Volume 5 of Bentham's Flora Australiensis. A substantial improvement on the previous arrangement, it would stand for over a century. It was eventually replaced by Alex George's 1981 arrangement, published in his classic...
in Flora Australiensis
Flora Australiensis
Flora Australiensis: a description of the plants of the Australian Territory, more commonly referred to as Flora Australiensis, and also known by its standard abbreviation Fl. Austral., is a seven-volume flora of Australia published between 1863 and 1878 by George Bentham, with the assistance of...
, he discarded Meissner's series, placing all the species with hooked styles together in a section that he named Oncostylis
Banksia sect. Oncostylis
Banksia sect. Oncostylis is one of four sections of subgenus Banksia subg. Banksia. It contains those Banksia species with hooked pistils. All of the species in Oncostylis also exhibit a top-down sequence of flower anthesis, except for Banksia nutans which is bottom-up.Banksia sect...
. This arrangement would stand for over a century.
In 1891, Otto Kuntze
Otto Kuntze
Otto Carl Ernst Kuntze was a German botanist.-Biography:Otto Kuntze was born in Leipzig.An apothecary in his early career, he published an essay entitled Pocket Fauna of Leipzig. Between 1863 and...
challenged the generic name Banksia L.f.
Carolus Linnaeus the Younger
Carl Linnaeus the Younger, Carl von Linné or Carolus Linnaeus the Younger was a Swedish naturalist...
, on the grounds that the name Banksia had previously been published in 1775 as Banksia J.R.Forst
Johann Reinhold Forster
Johann Reinhold Forster was a German Lutheran pastor and naturalist of partial Scottish descent who made contributions to the early ornithology of Europe and North America...
& G.Forst
Georg Forster
Johann Georg Adam Forster was a German naturalist, ethnologist, travel writer, journalist, and revolutionary. At an early age, he accompanied his father on several scientific expeditions, including James Cook's second voyage to the Pacific...
, referring to the genus now known as Pimelea
Pimelea
Pimelea is a genus of plants belonging to the family Thymelaeaceae. There are about 80 species in the genus, native to Australia and New Zealand. Many of the species are poisonous to cattle.Selected species...
. 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 nomenclatural synonym of B. brownii.
Alex George
Alex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...
published a new taxonomic arrangement of Banksia in his landmark 1981 monograph The genus Banksia L.f. (Proteaceae)
The genus Banksia L.f. (Proteaceae)
The genus Banksia L.f. is a 1981 monograph by Alex George on the taxonomy of the plant genus Banksia. Published by the Western Australian Herbarium as Nuytsia 3, it presented George's taxonomic arrangement of Banksia, the first major taxonomic revision of the genus since George Bentham published...
. Endlicher's Eubanksia became B. subg. Banksia
Banksia subg. Banksia
Banksia subg. Banksia is a valid botanic name for a subgenus of Banksia. As an autonym, it necessarily contains the type species of Banksia, B. serrata . Within this constraint, however, there have been various circumscriptions.-Banksia verae:B. subg...
, and was divided into three sections, one of which was Oncostylis. Oncostylis was further divided into four series, with B. brownii placed in series Spicigerae
Banksia ser. Spicigerae
Banksia ser. Spicigerae is a taxonomic series in the genus Banksia. It consists of the seven species in section Oncostylis that have cylindrical inflorescences. These range in form from small shrubs to tall trees. The leaves grow in either an alternate or whorled pattern, with various shape forms...
because its inflorescences are cylindrical.
In 1996, Kevin Thiele
Kevin Thiele
Kevin R. Thiele is curator of the Western Australian Herbarium. His research interests include the systematics of the plant families Proteaceae, Rhamnaceae and Violaceae, and the conservation ecology of grassy woodland ecosystems...
and Pauline Ladiges published a new arrangement for the genus, after cladistic
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
analyses yielded a cladogram
Cladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
significantly different from George's arrangement. Thiele and Ladiges' arrangement
Thiele and Ladiges' taxonomic arrangement of Banksia
Kevin Thiele and Pauline Ladiges' taxonomic arrangement of Banksia, published in 1996, was a novel taxonomic arrangement that was intended to align the taxonomy of Banksia more closely with the phylogeny that they had inferred from their cladistic analysis of the genus...
retained B. brownii in series Spicigerae, placing it in B. subser. Occidentales along with B. occidentalis
Banksia occidentalis
The Red Swamp Banksia or Waterbush is a species of shrub or small tree in the plant genus Banksia. It occurs on the south coast of Western Australia in three disjunct populations: at Augusta, around Albany and in the Esperance area.A 1980 field study at Cheyne beach showed it to be pollinated by...
(Red Swamp Banksia), B. seminuda
Banksia seminuda
Banksia seminuda, commonly known as the River Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from Dwellingup to the Broke Inlet east of Denmark . It is often mistaken for and was originally considered a subspecies of the Banksia littoralis...
(River Banksia), B. verticillata
Banksia verticillata
Banksia verticillata, commonly known as Granite Banksia or Albany Banksia, is a species of shrub or tree of the genus Banksia in the Proteaceae family. It is native to the southwest of Western Australia and can reach up to 3 m in height. It can grow taller to 5 m in sheltered areas,...
(Granite Banksia) and B. littoralis
Banksia littoralis
Banksia littoralis, commonly known as the Swamp Banksia, Swamp Oak, Pungura and the Western Swamp Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from the south eastern metropolitan area of Perth to the Stirling Range and Albany...
(Swamp Banksia). This arrangement stood until 1999, when George effectively reverted to his 1981 arrangement in his monograph for the Flora of Australia
Flora of Australia (series)
The Flora of Australia is a 59 volume series describing the vascular plants, bryophytes and lichens present in Australia and its external territories...
series.
Under George's taxonomic arrangement of Banksia
George's taxonomic arrangement of Banksia
Alex George's taxonomic arrangement of Banksia was the first modern-day arrangement for that genus. First published in 1981 in the classic monograph The genus Banksia L.f. , it superseded the arrangement of George Bentham, which had stood for over a hundred years. It was overturned in 1996 by Kevin...
, B. brownii
- Genus BanksiaBanksiaBanksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. When it comes to size, banksias range from prostrate woody shrubs to trees up...
Banksia subg. BanksiaBanksia subg. Banksia is a valid botanic name for a subgenus of Banksia. As an autonym, it necessarily contains the type species of Banksia, B. serrata . Within this constraint, however, there have been various circumscriptions.-Banksia verae:B. subg...
- Section BanksiaBanksia sect. BanksiaBanksia sect. Banksia is one of four sections of Banksia subgenus Banksia. It contains those species of subgenus Banksia with straight or sometimes curved but not hooked styles. These species all have cylindrical inflorescences and usually exhibit a bottom-up sequence of flower anthesis...
- Section CoccineaBanksia coccineaBanksia coccinea, commonly known as the Scarlet Banksia, Waratah Banksia or Albany Banksia, is an erect shrub or small tree in the plant genus Banksia...
- Section OncostylisBanksia sect. OncostylisBanksia sect. Oncostylis is one of four sections of subgenus Banksia subg. Banksia. It contains those Banksia species with hooked pistils. All of the species in Oncostylis also exhibit a top-down sequence of flower anthesis, except for Banksia nutans which is bottom-up.Banksia sect...
Banksia ser. SpicigeraeBanksia ser. Spicigerae is a taxonomic series in the genus Banksia. It consists of the seven species in section Oncostylis that have cylindrical inflorescences. These range in form from small shrubs to tall trees. The leaves grow in either an alternate or whorled pattern, with various shape forms...
- B. spinulosaBanksia spinulosaThe Hairpin Banksia is a species of woody shrub, of the genus Banksia in the Proteaceae family, native to eastern Australia. Widely distributed, it is found as an understorey plant in open dry forest or heathland from Victoria to northern Queensland, generally on sandstone though sometimes also...
- B. ericifoliaBanksia ericifoliaBanksia ericifolia, the Heath-leaved Banksia , is a species of woody shrub of the Proteaceae family native to Australia. It grows in two separate regions of Central and Northern New South Wales east of the Great Dividing Range...
- B. verticillataBanksia verticillataBanksia verticillata, commonly known as Granite Banksia or Albany Banksia, is a species of shrub or tree of the genus Banksia in the Proteaceae family. It is native to the southwest of Western Australia and can reach up to 3 m in height. It can grow taller to 5 m in sheltered areas,...
- B. seminudaBanksia seminudaBanksia seminuda, commonly known as the River Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from Dwellingup to the Broke Inlet east of Denmark . It is often mistaken for and was originally considered a subspecies of the Banksia littoralis...
- B. littoralisBanksia littoralisBanksia littoralis, commonly known as the Swamp Banksia, Swamp Oak, Pungura and the Western Swamp Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from the south eastern metropolitan area of Perth to the Stirling Range and Albany...
- B. occidentalisBanksia occidentalisThe Red Swamp Banksia or Waterbush is a species of shrub or small tree in the plant genus Banksia. It occurs on the south coast of Western Australia in three disjunct populations: at Augusta, around Albany and in the Esperance area.A 1980 field study at Cheyne beach showed it to be pollinated by...
- B. brownii
- B. spinulosa
- Series TricuspidaeBanksia tricuspisThe Lesueur Banksia or Pine Banksia is a species of shrub or tree in the plant genus Banksia. It occurs within a geographic range of just 15 square kilometres near Jurien, Western Australia.-External links:...
- Series DryandroidaeBanksia dryandroidesBanksia dryandroides, the Dryandra-leaved Banksia, is a species of small shrub in the plant genus Banksia. It occurs in shrubland, coastal heath and woodland on the south coast of Western Australia between Two Peoples Bay and Cheyne Bay. The species is placed alone in series B. ser...
- Series AbietinaeBanksia ser. AbietinaeBanksia ser. Abietinae is avalid botanic name for a series of Banksia. First published by Carl Meissner in 1856, the name has had three circumscriptions.-According to Meissner:...
- Section Banksia
Banksia subg. Isostylis
Banksia subg. Isostylis is a subgenus of Banksia. It contains three closely related species, all of which occur only in Southwest Western Australia. Members of subgenus Isostylis have dome-shaped flower heads that are superficially similar to those of B. ser...
B. brownii'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.
Since 1998, Austin Mast
Austin Mast
Austin R. Mast is a research botanist. Born in 1972, he obtained a Ph.D. from the University of Wisconsin–Madison in 2000. He is currently an associate professor within the Department of Biological Science at Florida State University , and has been director of FSU's since August 2003.One of his...
has been publishing results of ongoing cladistic analyses of DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
data for the subtribe Banksiinae, which comprises Banksia and Dryandra
Dryandra
Banksia ser. Dryandra is a series of 94 species of shrub to small tree in the plant genus Banksia. It was considered a separate genus named Dryandra until early 2007, when it was merged into Banksia on the basis of extensive molecular and morphological evidence that Banksia was paraphyletic with...
. 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 B. nutans
Banksia nutans
Banksia nutans, commonly known as Nodding Banksia, is a species of shrub native to the south coast of Western Australia in the genus Banksia...
(Nodding Banksia) and B. quercifolia
Banksia quercifolia
The Oak-leaved Banksia is a species of shrub in the plant genus Banksia. It occurs on the south coast of Western Australia from D'Entrecasteaux National Park in the west to Mount Manypeaks in the east.-Ecology:...
(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
Paraphyly
A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...
of Banksia with respect to Dryandra. Early in 2007, Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae
Banksia subg. Spathulatae
Banksia subg. Spathulatae is a valid botanic name for a subgenus of Banksia. It was published in 2007 by Austin Mast and Kevin Thiele, and defined as containing all those Banksia species having spathulate cotyledons...
for the species having spoon-shaped cotyledon
Cotyledon
A cotyledon , is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon may become the embryonic first leaves of a seedling. The number of cotyledons present is one characteristic used by botanists to classify the flowering plants...
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.
Three genetically distinct forms of B. brownii are recognised: the better known forms are 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. Some horticulturists also recognise an intermediate form. Recent genetic testing has confirmed the existence of three distinct forms, but currently these have no taxonomic status.
Distribution and habitat
B. brownii occurs between AlbanyAlbany, Western Australia
Albany is a port city in the Great Southern region of Western Australia, some 418 km SE of Perth, the state capital. As of 2009, Albany's population was estimated at 33,600, making it the 6th-largest city in the state....
(35°S) and the Stirling Range
Stirling Range
The Stirling Range or Koikyennuruff is a range of mountains and hills in the Great Southern region of Western Australia, 337 km south-east of Perth. It is located at approximately and is over 60 km wide from west to east, stretching from the highway between Mount Barker and Cranbrook...
(34°24'S) in the southwest
Southwest Australia
Southwest Australia is a biodiversity hotspot that includes the Mediterranean forests, woodlands, and scrub ecoregions of Western Australia. The region has a wet-winter, dry-summer Mediterranean climate, one of five such regions in the world...
of Western Australia, at the juncture of the Esperance Plains
Esperance Plains
Esperance Plains, also known as Eyre Botanical District, is a biogeographic region in southern Western Australia. Located on the south coast between the Avon Wheatbelt and Hampton regions, and bordered to the north by the Mallee region, it is a plain punctuated by granite and quartz outcrops and...
, Warren
Warren (biogeographic region)
Warren, also known as Karri Forest Region and the Jarrah-Karri forest and shrublands ecoregion, is a biogeographic region in southern Western Australia. Located in the southwest corner of Western Australia between Cape Naturaliste and Albany, it is bordered to the north and east by the Jarrah...
and Jarrah Forest
Jarrah Forest
Jarrah Forest is an Interim Biogeographic Regionalisation for Australia region in Western Australia.-Location and description:The ecoregion stands on the 300m high Yilgarn block inland plateau and includes wooded valleys such as those of Western Australia's Murray River and the Helena River near...
biogeographic
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
regions. This is the taxonomically richest area for Banksia, with 19 species, of which six are endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
, 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). 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
Laterite
Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock...
; Stirling Range populations occur at altitudes of between 500 and 1100 metres (1640–3960 ft), among heath
Heath (habitat)
A heath or heathland is a dwarf-shrub habitat found on mainly low quality acidic soils, characterised by open, low growing woody vegetation, often dominated by plants of the Ericaceae. There are some clear differences between heath and moorland...
on rocky mountain slopes and tops, and in shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
in gullies.
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. The total number of plants is estimated at around 1000.
Ecology
Coastal plants begin to flower at around five years from seed, but plants in the Stirling Range take much longer to mature. In one Stirling Range population, only 15% of plants had flowered after eight years. 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.As with other Banksia species, B. brownii is a heavy producer of nectar
Nectar (plant)
Nectar is a sugar-rich liquid produced by plants. It is produced in glands called nectaries, either within the flowers, in which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide anti-herbivore protection...
, and serves as a food source for a range of nectariferous birds, mammals and insects. Honeyeaters such as Phylidonyris novaehollandiae (New Holland Honeyeater), Acanthorhynchus superciliosus (Western Spinebill) and Anthochaera carunculata (Red Wattlebird) are frequent visitors that often carry heavy pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
loads, making them important pollinators. Nocturnal mammals such as Rattus fuscipes (Bush Rat) and Tarsipes rostratus (Honey Possum) 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 Apis mellifera (Western Honeybee), native bees, flies
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
and ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
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.
The species is partly self-compatible
Self-pollination
Self-pollination is a form of pollination that can occur when a flower has both stamen and a carpel in which the cultivar or species is self fertile and the stamens and the sticky stigma of the carpel contact each other in order to accomplish pollination...
, as some seed is set when pollinators are excluded. Selection against self-pollinated seed has been observed, but the species has nonetheless been shown to have one of the lowest outcrossing
Outcrossing
Outcrossing is the practice of introducing unrelated genetic material into a breeding line. It increases genetic diversity, thus reducing the probability of all individuals being subject to disease or reducing genetic abnormalities...
rates of any Banksia. This is probably caused by the small population sizes, which increase the probability of self-fertilisation, and may discourage visits by pollinators.
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. Seed survival rates are similarly low. More than half of a plant's seed crop may be lost to the larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e of moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
s and weevil
Weevil
A weevil is any beetle from the Curculionoidea superfamily. They are usually small, less than , and herbivorous. There are over 60,000 species in several families, mostly in the family Curculionidae...
s, which burrow into the cobs to eat the seeds and pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
te in the follicles; and further seed losses are caused by granivorous birds such as cockatoo
Cockatoo
A cockatoo is any of the 21 species belonging to the bird family Cacatuidae. Along with the Psittacidae and the Strigopidae , they make up the parrot order Psittaciformes . Placement of the cockatoos as a separate family is fairly undisputed, although many aspects of the other living lineages of...
s, which break off the cobs to eat both the seeds and the insect larvae.
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
Lignotuber
A lignotuber is a starchy swelling of the root crown possessed by some plants as a protection against destruction of the plant stem by fire. The crown contains buds from which new stems may sprout, and a sufficient store of nutrients to support a period of growth in the absence of...
s, but the subsequent shedding of seed allows the population to regenerate. 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.
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 vigourHeterosis
Heterosis, or hybrid vigor, or outbreeding enhancement, is the improved or increased function of any biological quality in a hybrid offspring. The adjective derived from heterosis is heterotic....
. Climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
is also of concern: depending on the severity of change, the range of this species is predicted to contract by 30% to 50% by 2080.
B. brownii has been assessed as having a very high risk of extinction. It is estimated that without protective measures in place, it would be extinct within a decade; 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." The species has not yet been formally assessed for the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
, but warrants a "Critically Endangered (CR)" ranking because populations are projected to decline by more than 80% within the next three generations. It is currently listed as "Endangered" under Australia's Environment Protection and Biodiversity Conservation Act 1999
Environment Protection and Biodiversity Conservation Act 1999
The Environment Protection and Biodiversity Conservation Act 1999 is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and culturally significant places...
(EPBC Act), and "Rare" under Western Australia's Wildlife Conservation Act 1950
Wildlife Conservation Act 1950
The Wildlife Conservation Act 1950 is an act of the Western Australian Parliament that provides the statute relating to conservation and legal protection of flora and fauna....
. These acts
Statute
A statute is a formal written enactment of a legislative authority that governs a state, city, or county. Typically, statutes command or prohibit something, or declare policy. The word is often used to distinguish law made by legislative bodies from case law, decided by courts, and regulations...
provide legislative protection against a range of potential threats, including commercial harvesting of flowers and land clearing. Further statutory protection is afforded by the fact that populations occur within the Eastern Stirling Range Montane Heath and Thicket threatened ecological community
Threatened ecological community
Threatened ecological community is a term used in Australia for ecosystems that are in danger of being lost due to some threatening process. Federally, threatened ecological communities are identified and protected under the Environment Protection and Biodiversity Conservation Act 1999. Some states...
, which is listed as "Endangered" under the EPBC Act, and the Montane Mallee Thicket of the Stirling Range threatened ecology community, which has been assessed as "Endangered" by the Western Australian government; and by the presence of northern population within the Stirling Range National Park
Stirling Range National Park
Stirling Range National Park is a national park in the Great Southern region of Western Australia, approximately 337 km south-east of Perth.-Description:...
.
A five-year interim management plan was put in place by the Western Australia's Department of Environment and Conservation in October 2005. Actions under that plan include regular monitoring of populations, management of the threats of fire and P. cinnamomi, and the cold storage of seed. As of December 2009 a recovery plan is being developed. There is also a translocation project underway.
Disease
The main threat to B. brownii is dieback caused by the introducedIntroduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
plant pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
P. cinnamomi, a soil-borne water mould
Water mould
Oömycota or oömycetes form a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms . They are filamentous, microscopic, absorptive organisms that reproduce both sexually and asexually...
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". As of 2007, all major populations of B. brownii, and all but one minor population, are suffering from dieback. Moreover, all populations are in an area vulnerable to dieback, so even the uninfected population is considered under threat. According to Byron Lamont
Byron Lamont
Professor Byron Barnard Lamont is a Western Australian botanist. He is currently a senior researcher within the Department of Environmental Biology of Curtin University of Technology...
, "the demise of this species in the wild appears imminent."
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
A phosphite is a salt of phosphorous acid. The phosphite ion is a polyatomic ion with a phosphorus central atom where phosphorus has an oxidation state of +3...
. Phosphite boosts the resistance of both infected and uninfected plants, and also acts as a direct fungicide
Fungicide
Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals...
. Aerial spraying of phosphite boosts plant survival and slows the spread of infection, but must be carefully managed as studies have shown that foliar spraying of phosphite adversely affects root and shoot growth. Direct injection of phosphite into the stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
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
Armillaria luteobubalina
Armillaria luteobubalina, commonly known as the Australian honey fungus, is a species of mushroom in the family Physalacriaceae. Widely distributed in southern Australia, the fungus is responsible for a disease known as Armillaria root rot, a primary cause of Eucalyptus tree death and forest dieback...
and the aerial canker
Canker
Canker and anthracnose are general terms for a large number of different plant diseases, characterised by broadly similar symptoms including the appearance of small areas of dead tissue, which grow slowly, often over a period of years. Some are of only minor consequence, but others are ultimately...
fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
Zythiostroma
Zythiostroma
Zythiostroma is a genus of canker fungus in the Nectriaceae family. The two or three species in the genus, which are anamorphs of the genus Nectria, have been found in Europe and Java.-Taxonomy:...
.
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. 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.Ex situ conservation measures
Because of the difficulty of conserving B. brownii in its present disease-exposed locations, it is an especially suitable candidate for ex situ conservation measures, such as the cold-storage of seed, and the translocation of plants to disease-free locations. Seed of B. brownii has been collected by Western Australia's Threatened Flora Seed Centre, and placed in cold-storage both in Perth and at KewRoyal Botanic Gardens, Kew
The Royal Botanic Gardens, Kew, usually referred to as Kew Gardens, is 121 hectares of gardens and botanical glasshouses between Richmond and Kew in southwest London, England. "The Royal Botanic Gardens, Kew" and the brand name "Kew" are also used as umbrella terms for the institution that runs...
's Millennium Seed Bank. This includes seed collected from populations that have since become extinct. In 2008, some of this seed was germinated, and seedlings were planted at a location near Albany. Genetic analysis of the seedlings revealed some genetic diversity that was not present in any extant population. The conservation of these seeds had thus preserved some of the species' genetic diversity that would otherwise have been lost through population extinction, providing a powerful example of the importance of seed banking to conservation efforts. A seed orchard was planted in 2007, and by 2010 this had yielded over 400 disease-free, healthy plants, some of which had grown more than three times the rate of those in the wild.
Cultivation
With large metallic red inflorescences and attractive feathery leaves that are perhaps the softest of all Banksia species, B. brownii is highly valued by Australia's horticultural and cut flower industries. Seeds and plants are readily available in Australian nurseries, and it is widely cultivated in areas not exposed to dieback. Seeds do not require any treatment, and take 20 to 50 days to germinate. The plant 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.The main obstacle to cultivation is the species' extreme sensitivity to dieback, which is widespread in suburban gardens. However, the species has been successfully grafted
Grafting
Grafting is a horticultural technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together. This vascular joining is called inosculation...
onto a rootstock
Rootstock
A rootstock is a plant, and sometimes just the stump, which already has an established, healthy root system, used for grafting a cutting or budding from another plant. The tree part being grafted onto the rootstock is usually called the scion...
of B. integrifolia
Banksia integrifolia
Banksia integrifolia, commonly known as Coast Banksia, is a species of tree that grows along the east coast of Australia. One of the most widely distributed Banksia species, it occurs between Victoria and Central Queensland in a broad range of habitats, from coastal dunes to mountains...
(Coast Banksia), which renders it hardy on a range of soils.