Banksia cuneata
Encyclopedia
Banksia cuneata, commonly known as Matchstick Banksia or Quairading Banksia, is an endangered species
of flowering plants in the Proteaceae
family. Endemic to southwest
Western Australia
, it belongs to Banksia subg. Isostylis
, a subgenus of three closely related Banksia
species with inflorescence
s or flower clusters that are dome-shaped heads rather than characteristic Banksia flower spikes. A shrub or small tree up to 5 m (15 ft) high, it has prickly foliage and pink and cream flowers. The common name Matchstick Banksia arises from the blooms in late bud, the individual buds of which resemble matchsticks. The species is pollinated
by honeyeater
s (Meliphagidae).
Although B. cuneata was first collected before 1880, it was not until 1981 that Australian botanist Alex George
formally described and named the species. There are two genetically distinct population groups, but no recognised varieties. This Banksia is classified as endangered, surviving in fragments of remnant bushland in a region which has been 93% cleared for agriculture. As Banksia cuneata is killed by fire and regenerates from seed, it is highly sensitive to bushfire frequency—fires recurring within four years could wipe out populations of plants not yet mature enough to set seed. Banksia cuneata is rarely cultivated, and its prickly foliage limits its utility in the cut flower industry.
. It has one or more main trunks with smooth grey bark, and many branches. Young stems are covered in coarse hairs, but these are lost as the stems age. The leaves are wedge-shaped with serrated edges, having from one to five teeth along each side. They range from 1 to 4 cm (0.4–1.6 in) long and 0.5 to 1.5 cm (0.2–0.6 in) wide, on a petiole
of 2 to 3 mm. The upper surface is dull green; as with the stems, both leaf surfaces are covered in coarse hairs when young, but these are soon lost.
Flowers occur in dome-shaped heads from three to four cm (1.2–1.6 in) in diameter, growing at the ends of branches. They comprise 55 to 65 individual flowers, enclosed at the base by a whorl of short involucral bracts. As with most other Proteaceae
, each flower consists of a perianth
comprising four united tepal
s, and a single pistil
, the style of which is initially enclosed within the limb of the perianth, but breaks free at anthesis
. In B. cuneata, the perianth is about 2.5 cm (1 in) long, with a limb of about 0.4 cm (0.16 in). Prior to anthesis, the long thin perianth topped by a prominent limb resembles a match
stick, which explains one common name for this species. At first, the perianth is mostly cream, being pink only near its base; it later becomes pink throughout. The style is initially cream, but turns red; the pollen presenter
is green.
Old flowers soon fall from the flower heads (often called cones at this stage), revealing a woody base which may have up to five follicle
s embedded in it. These are a mottled grey colour, smooth, felted with short fine hairs, and measure from 1 to 1.3 cm (0.4–0.5 in) high, 1.7 to 2.1 cm (0.6–0.8 in) along the seam, and 0.9 to 1.2 cm (0.4–0.5 in) across the seam. Each follicle contains up to two seeds; these are roughly triangular in shape, with a large papery wing.
Banksia cuneata is most easily distinguished from the other two species in B. subg. Isostylis by its brighter flowers and duller leaves. It further differs from B. ilicifolia
in its smaller habit; its smooth bark; its smaller leaves, flowers and fruit; and in its sequence of flower colour changes. The leaves, flowers and fruit of B. oligantha
are smaller still, and its foliage is not as prickly as that of B. cuneata.
some time before 1880. What would later become the type specimen
for the species was collected by Western Australian botanist and Banksia expert Alex George
on 20 November 1971, from Badjaling Nature Reserve
, about 8 km (5 mi) east of Quairading, at 31°59′S 117°30′E. The species was finally published by George nearly a decade later, in his 1981 monograph "The genus Banksia L.f. (Proteaceae)
". The specific epithet is from the Latin
cuneatus ("wedge-shaped"), in reference to the shape of the leaves.
The species has an uneventful nomenclatural history: it has no synonyms
, and no subspecies or varieties have been published. It bears the common name
s of Matchstick Banksia or Quairading Banksia,.
because of its dome-shaped flower heads. A 1996 cladistic
analysis of the genus by botanists Kevin Thiele
and Pauline Ladiges yielded no information about the circumscription of B. subg. Isostylis, nor of the relationships within it, so George's placement of this species was retained in their arrangement
. That arrangement was not accepted by George, and was largely discarded by him in his 1999 arrangement
. The placement of B. cuneata there was unaffected, and can be summarised as follows:
Since 1998, American botanist Austin Mast
and co-authors have been publishing results of ongoing cladistic analyses of DNA sequence
data for the subtribe Banksiinae
, which then comprised genera Banksia and Dryandra. Their analyses suggest a phylogeny
that differs greatly from George's taxonomic arrangement. Banksia cuneata resolves as the next closest relative, or 'sister', to a clade
containing B. ilicifolia and B. oligantha, suggesting a monophyletic
B. subg. Isostylis; but the clade appears fairly derived
(that it, it evolved relatively recently), suggesting that B. subg. Isostylis may not merit subgeneric rank.
Early in 2007, Mast and Thiele rearranged the genus Banksia by merging Dryandra into it, and published B. subg. Spathulatae
for the taxa having spoon-shaped cotyledon
s; thus B. subg. Banksia was redefined as encompassing taxa lacking spoon-shaped cotyledons. 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. cuneata is placed in B. subg. Banksia.
of the three species, a 2004 study of genetic divergence
within the subgenus yielded both other possibilities: some analyses suggested B. ilicifolia as basal, while others suggested B. oligantha. Further complicating the situation is the southernmost population of B. cuneata, which has both genetic and phenetic
affinities with B. oligantha located to the southeast. The origin of this population is unknown. It might have arisen through hybridisation, or it may be a transitional or even ancestral form. Finally, biogeographical
factors suggest that B. ilicifolia would be the most basal of the three species: it occurs in the High Rainfall Zone
where relict
ual species are most common, whereas the others are restricted to the Transitional Rainfall Zone
, where more recently evolved species are most common.
and Quairading
, in Western Australia
. It favours deep yellow sand at elevations between 230 and 300 m (700–1000 ft), in woodland
habitat. It often grows in association with Banksia prionotes
and Xylomelum angustifolium
.
Reports on the number of populations and individuals vary widely. A survey in 1982 reported 450 plants in five populations, with the largest population comprising 300 plants. In 1988, however, only four populations comprising 300 plants were found; surprisingly, only fifty plants could be found in the location where a population of 300 had previously been reported; yet there were no dead plants, and no evidence of disturbance. Since then the number of populations reported have ranged from 6 to 11, and reports of the total number of plants have ranged from 340 to 580.
The structure of B. cuneata
, suggests that autogamous self-fertilisation must be common. This is countered, however, by protandry
: pollen
is released well before the pistil
becomes receptive; usually by the time the pistil becomes receptive most of the pollen has either been transferred, or has lost its viability. This strategy is effective against individual flowers fertilising themselves, but does nothing to prevent geitonogamy
: fertilisation of flowers by different flowers on the same plant. Because of the way flowers are clustered together in heads, this must be quite common, although whether it results in successful fruit set is another matter: isozyme studies have observed "intense selection against homozygotes", a fairly common outbreeding strategy in plants that set lots of seed.
Assessments of the mating system
of this species have found that outcrossing
rates vary between populations. Populations in relatively intact bushland have high outcrossing rates, but those in more disturbed environments are both more inbred
on average, and more variable. This has been attributed to a range of causes. Firstly, the higher density of disturbed populations leads to greater rates of mating between neighbouring plants, resulting in more genetic structure
and thus more effective selfing
. Secondly, disturbed populations usually lack an understorey
, and so cannot support a resident population of honeyeaters; instead, they rely upon occasional visitors for pollination. The greatly reduced pollination rates means fewer outcrossing fertilisations on average, leading to less selection
against inbred fertilisations; and the sporadic presence of pollinators leads to outcrossing variability.
No seed is set when pollinators are excluded
, indicating that seed set must be pollinator-limited. About 96% of fertilized follicles mature, and about 82% of seeds mature. These are very high numbers for Banksia, indicating that there are no problems with nutrient supply. This species produces an unusually high number of old flowerheads, or cones, per plant—typically more than 500. However there are an unusually low number of follicles per cone—often only one. Thus the number of follicles per plant ends up roughly average for a Banksia species.
Banksia cuneata lacks a lignotuber
, so plants are killed by bushfire. However, this species is strongly serotinous
: seed is released only following a fire. Thus plants accumulate an aerial seed bank
in fire intervals, which is released all at once after a fire, ensuring population regeneration. The mechanism is a resin
that seals the follicles shut, preventing dehiscence
; the heat of a bushfire melts the resin, and the follicles open. Intense fires cause the immediate release of the seed and seed separator
, but after cooler fires the seed separator often remains in place, blocking the follicle exit and preventing seed release. The wings on the seed separator are hygroscopic
; they draw together when moistened, then reflex out again as they dry. Thus they lever themselves, and the seeds, out of the follicle over the course of one or more wet-dry cycles, ensuring that seed is released only after rain has fallen. The juvenile period for B. cuneata is around four years. Populations are very vulnerable to fire during this period, as fire will wipe out the entire population and there will be no seed from which it might recover. A model-based investigation found that the optimal fire interval for maximising population size over the medium term is around 15 years. More frequent fires reduce population size by killing adults before they have reached their full fecundity
. Less frequent fires reduce population size because there are fewer opportunities for seed dispersal and germination. However the optimal fire interval for minimising the risk of extinct in the long term is probably much longer.
B. cuneata is very unusual in apparently suffering no seed loss due to granivory
. In nearly all other species, burrowing insect
larva
e eat a large proportion of seeds, and birds cause further losses in breaking open cones in search of larvae to eat. The seed-eating insects are mostly species-specific, and it appears that no insect species has adapted to B. cuneata. Possible reasons for this are the very low seed counts, and the rarity of the species, both of which offer little incentive for adaptation to the species. There is also no evidence of granivores feeding on seed after it has fallen. As a result, this species has the highest rate of seed viability recorded for a Banksia species: in one study, 74% of all seed produced in the previous 12 years was viable. This was largely accounted for by seed under 9 years old, about 90% of which is viable. After the ninth year, viability is lost rapidly as the follicles decay and senescence
sets in. Seed production itself starts very slowly. On average, plants aged between 5 and 12 years have about 18 seeds stored in their canopy. Storage increases exponentially, however, and 25-year old plants often have tens of thousands of seeds. Seed production probably never plateaus. In fact, by the time a plant is twenty years old it has accumulated such a great weight of cones that major branches begin to break away; and by the age of thirty, plants have broken branches more often than not. As plants age, branch breakage increasingly leads to plant death, and it is unlikely that any plants live to more than 45 years.
The high seed maturation and viability rates are offset, however, by an extremely low seedling survival rate. This is almost solely due to moisture stress. In one study, an estimated 17,100 viable seeds were released following an experimental fire. Fewer than 5% of them germinated, and only eleven plants survived the first summer drought. The last plants to die were in depressions, in shaded areas or amongst leaf litter; and the eleven survivors were all on road shoulders, where they benefited from road runoff
and a 3 cm (1.2 in) thick mulch
of pisolitic
laterite
. The inevitable conclusion is that seedling survival is primarily determined by water availability.
after a 1982 survey found only five populations comprising about 450 plants. The largest population, consisting of around 300 plants, was on a conservation reserve, but all others were on road verges, and contained only 50–70 plants each. However, since then more plants have been located, and populations have been found to be gradually increasing in response to a number of conservation
measures including fencing and baiting of rabbit
s. In recognition of its slight recovery, it is now considered endangered but no longer critically so.
In April 1987, Western Australia's Department of Environment and Conservation burnt part of one population in an experimental regeneration fire. The mature plants were killed, and the seedlings that volunteer
ed did not survive the summer drought
. A Matchstick Banksia Recovery Team was established in 1995, and over time they succeeded in establishing a large number of seedlings. A large adult population was destroyed by bushfire in 1996, causing further concern, but this was followed by the recruitment of large numbers of seedlings.
Threats to B. cuneata include land clearing, which leads to direct plant loss and population fragmentation, grazing
pressure, competition from exotic weeds, changes to the fire regime
, and encroaching salinity
. The Banksia Atlas
survey found one population to be on the side of a road; the plants were aging with no new seedlings noted, and the site was weed-infested. A large part of the surviving populations are on private land, and depend on good relationships with local landowners. Many have obliged by fencing off areas and restricting entry of rabbits. There has been some attempt by CALM to translocate populations away from hazardous areas; these have met with some success, helped with watering in the first year.
within individual populations of B. cuneata are unusually high for a rare and endangered species, but the populations fall into two genetically distinct groups. These are separated not by geographical distance but by the Salt River
, an ephemeral
saline river system that provides a habitat unsuitable for both B. cuneata and the birds that pollinate it. It thus functions as a barrier to the exchange of genetic material, allowing populations on different sides of the river to diverge
through genetic drift
. The implication for conservation is that effort should be invested on both sides of the river in order to conserve as much genetic diversity as possible. It was suggested that one large population from each population group would probably be adequate. More recently, however, a model-based risk analysis found that the population size required to reduce extinction risk to acceptable levels is more than ten times the current population size. This leads to the conclusion that all populations, and all available habitat, should be protected.
dieback has not been identified as a threat to this species, but testing has found it to be highly susceptible; in one study it exhibited the highest susceptibility of 49 Banksia species studied, with 80% of plants dead within 96 days of inoculation with the disease, and 100% dead within a year.
. This was recognised as early as 1992, when it was noted that winter rainfall in the Quairading region had been falling by about 4% per decade, and that a continuation of this trend may reduce the species' distribution. Recently, a more thorough assessment of the potential impact of climate change on this species found that severe change is likely to lead to extinction
, and mild change to a reduction of its range by 80% by 2080. However, there may not be any range reduction at all under mid-severity climate change, depending on how effectively this species can migrate into newly habitable areas.
. Cutting
s yield unpredictable results. The plant itself prefers a deep, sandy, well-drained soil with a pH
of 6.0–7.0. It requires full sun, but some protection from the wind is recommended, as this is a fast-growing plant with spindly branches that are easily damaged by wind. A more compact form can be obtained by pruning the top quarter each year. This species has little appeal to the cut flower industry
, because of its prickly foliage, and its tendency to drip nectar.
Ironically, given its conservation status, Kingsley Dixon of Kings Park and Botanic Garden
suggested that it may have weed potential: the species was trialled as a cut flower crop on land north of Moore River, and seedlings were noted afterwards.
, and has been incorporated into the shire logo. There is a park named Cuneata Park in the town of Quairading
.
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...
of flowering plants in the Proteaceae
Proteaceae
Proteaceae is a family of flowering plants distributed in the Southern Hemisphere. The family comprises about 80 genera with about 1600 species. Together with the Platanaceae and Nelumbonaceae they make up the order Proteales. Well known genera include Protea, Banksia, Embothrium, Grevillea,...
family. Endemic to 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...
, it belongs to Banksia subg. Isostylis
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...
, a subgenus of three closely related 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...
species with 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 or flower clusters that are dome-shaped heads rather than characteristic Banksia flower spikes. A shrub or small tree up to 5 m (15 ft) high, it has prickly foliage and pink and cream flowers. The common name Matchstick Banksia arises from the blooms in late bud, the individual buds of which resemble matchsticks. The species is pollinated
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
by honeyeater
Honeyeater
The honeyeaters are a large and diverse family of small to medium sized birds most common in Australia and New Guinea, but also found in New Zealand, the Pacific islands as far east as Samoa and Tonga, and the islands to the north and west of New Guinea known as Wallacea...
s (Meliphagidae).
Although B. cuneata was first collected before 1880, it was not until 1981 that Australian botanist Alex George
Alex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...
formally described and named the species. There are two genetically distinct population groups, but no recognised varieties. This Banksia is classified as endangered, surviving in fragments of remnant bushland in a region which has been 93% cleared for agriculture. As Banksia cuneata is killed by fire and regenerates from seed, it is highly sensitive to bushfire frequency—fires recurring within four years could wipe out populations of plants not yet mature enough to set seed. Banksia cuneata is rarely cultivated, and its prickly foliage limits its utility in the cut flower industry.
Description
Banksia cuneata grows as a shrub or small tree up to 5 m (15 ft) high, without a lignotuberLignotuber
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...
. It has one or more main trunks with smooth grey bark, and many branches. Young stems are covered in coarse hairs, but these are lost as the stems age. The leaves are wedge-shaped with serrated edges, having from one to five teeth along each side. They range from 1 to 4 cm (0.4–1.6 in) long and 0.5 to 1.5 cm (0.2–0.6 in) wide, on a petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
of 2 to 3 mm. The upper surface is dull green; as with the stems, both leaf surfaces are covered in coarse hairs when young, but these are soon lost.
Flowers occur in dome-shaped heads from three to four cm (1.2–1.6 in) in diameter, growing at the ends of branches. They comprise 55 to 65 individual flowers, enclosed at the base by a whorl of short involucral bracts. As with most other Proteaceae
Proteaceae
Proteaceae is a family of flowering plants distributed in the Southern Hemisphere. The family comprises about 80 genera with about 1600 species. Together with the Platanaceae and Nelumbonaceae they make up the order Proteales. Well known genera include Protea, Banksia, Embothrium, Grevillea,...
, each flower consists of a perianth
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
comprising 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 a single pistil
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
, the style of which is initially enclosed within the limb of the perianth, 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...
. In B. cuneata, the perianth is about 2.5 cm (1 in) long, with a limb of about 0.4 cm (0.16 in). Prior to anthesis, the long thin perianth topped by a prominent limb resembles a match
Match
A match is a tool for starting a fire under controlled conditions. A typical modern match is made of a small wooden stick or stiff paper. One end is coated with a material that can be ignited by frictional heat generated by striking the match against a suitable surface...
stick, which explains one common name for this species. At first, the perianth is mostly cream, being pink only near its base; it later becomes pink throughout. The style is initially cream, but turns red; the pollen presenter
Pollen-presenter
A pollen-presenter is an area on the tip of the pistil in flowers of plants of the family Proteaceae. In this family, the anthers are difficult of access for potential pollination vectors such as bees, birds and nectariferous mammals....
is green.
Old flowers soon fall from the flower heads (often called cones at this stage), revealing a woody base which may have up to five follicle
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....
s embedded in it. These are a mottled grey colour, smooth, felted with short fine hairs, and measure from 1 to 1.3 cm (0.4–0.5 in) high, 1.7 to 2.1 cm (0.6–0.8 in) along the seam, and 0.9 to 1.2 cm (0.4–0.5 in) across the seam. Each follicle contains up to two seeds; these are roughly triangular in shape, with a large papery wing.
Banksia cuneata is most easily distinguished from the other two species in B. subg. Isostylis by its brighter flowers and duller leaves. It further differs from B. ilicifolia
Banksia ilicifolia
Banksia ilicifolia, commonly known as Holly-leaved Banksia, is a tree in the plant Proteaceae family. Endemic to southwest Western Australia, it belongs to Banksia subg. Isostylis, a subgenus of three closely related Banksia species with inflorescences that are dome-shaped heads rather than...
in its smaller habit; its smooth bark; its smaller leaves, flowers and fruit; and in its sequence of flower colour changes. The leaves, flowers and fruit of B. oligantha
Banksia oligantha
Banksia oligantha, commonly known as Wagin Banksia, is an endangered species in the plant family Proteaceae endemic to south west Western Australia. It belongs to Banksia subg. Isostylis, a subgenus of three closely related Banksia species with dome-shaped heads as inflorescences, rather than...
are smaller still, and its foliage is not as prickly as that of B. cuneata.
Discovery and naming
The earliest known specimen collection of B. cuneata was made by Julia WellsJulia Wells
Julia Susannah Harris née Wells is notable for having collected some significant botanical specimens in what is now the wheatbelt region of Western Australia...
some time before 1880. What would later become the type specimen
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
for the species was collected by Western Australian botanist and Banksia expert Alex George
Alex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...
on 20 November 1971, from Badjaling Nature Reserve
Badjaling Nature Reserve
Badjaling Nature Reserve is a nature reserve located at Badjaling in the Wheatbelt region of Western Australia. Nominally located at , it is a 272 hectare reserve of native bushland, surrounded by land long since cleared for agriculture....
, about 8 km (5 mi) east of Quairading, at 31°59′S 117°30′E. The species was finally published by George nearly a decade later, in his 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...
". The specific epithet is from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
cuneatus ("wedge-shaped"), in reference to the shape of the leaves.
The species has an uneventful nomenclatural history: it has no synonyms
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
, and no subspecies or varieties have been published. It bears the common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s of Matchstick Banksia or Quairading Banksia,.
Infrageneric placement
George placed B. cuneata in subgenus IsostylisBanksia 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...
because of its dome-shaped flower heads. A 1996 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...
analysis of the genus by botanists 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 yielded no information about the circumscription of B. subg. Isostylis, nor of the relationships within it, so George's placement of this species was retained in their 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...
. That arrangement was not accepted by George, and was largely discarded by him in his 1999 arrangement
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...
. The placement of B. cuneata there was unaffected, and can be summarised as follows:
- 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...
- B. subg. BanksiaBanksia 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...
(3 sections, 11 series, 73 species, 11 subspecies, 14 varieties) - B. subg. IsostylisBanksia subg. IsostylisBanksia 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. ilicifoliaBanksia ilicifoliaBanksia ilicifolia, commonly known as Holly-leaved Banksia, is a tree in the plant Proteaceae family. Endemic to southwest Western Australia, it belongs to Banksia subg. Isostylis, a subgenus of three closely related Banksia species with inflorescences that are dome-shaped heads rather than...
- B. oliganthaBanksia oliganthaBanksia oligantha, commonly known as Wagin Banksia, is an endangered species in the plant family Proteaceae endemic to south west Western Australia. It belongs to Banksia subg. Isostylis, a subgenus of three closely related Banksia species with dome-shaped heads as inflorescences, rather than...
- B. cuneata
- B. ilicifolia
- B. subg. Banksia
Since 1998, American botanist 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...
and co-authors have 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
Grevilleoideae
Grevilleoideae is a subfamily of the Proteaceae family of flowering plants. Mainly restricted to the southern hemisphere, it contains around 44 genera and about 950 species. Genera include Banksia, Grevillea and Macadamia.-Description:...
, which then comprised genera Banksia and Dryandra. Their analyses suggest a phylogeny
Phylogenetics
In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...
that differs greatly from George's taxonomic arrangement. Banksia cuneata resolves as the next closest relative, or 'sister', to a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
containing B. ilicifolia and B. oligantha, suggesting a monophyletic
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
B. subg. Isostylis; but the clade appears fairly derived
Derived
In phylogenetics, a derived trait is a trait that is present in an organism, but was absent in the last common ancestor of the group being considered. This may also refer to structures that are not present in an organism, but were present in its ancestors, i.e. traits that have undergone secondary...
(that it, it evolved relatively recently), suggesting that B. subg. Isostylis may not merit subgeneric rank.
Early in 2007, Mast and Thiele rearranged the genus Banksia by merging Dryandra into it, and published 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 taxa 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; thus B. subg. Banksia was redefined as encompassing taxa lacking spoon-shaped cotyledons. 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. cuneata is placed in B. subg. Banksia.
Phylogeny
Relationships between B. cuneata and the other members of B. subg. Isostylis still remain unclear. Though Mast's studies found B. cuneata to be the most basalBasal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
of the three species, a 2004 study of genetic divergence
Genetic divergence
Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes through time, often after the populations have become reproductively isolated for some period of time...
within the subgenus yielded both other possibilities: some analyses suggested B. ilicifolia as basal, while others suggested B. oligantha. Further complicating the situation is the southernmost population of B. cuneata, which has both genetic and phenetic
Phenetics
In biology, phenetics, also known as taximetrics, is an attempt to classify organisms based on overall similarity, usually in morphology or other observable traits, regardless of their phylogeny or evolutionary relation. It is closely related to numerical taxonomy which is concerned with the use of...
affinities with B. oligantha located to the southeast. The origin of this population is unknown. It might have arisen through hybridisation, or it may be a transitional or even ancestral form. Finally, biogeographical
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...
factors suggest that B. ilicifolia would be the most basal of the three species: it occurs in the High Rainfall Zone
High Rainfall Zone
The High Rainfall Zone is one of three biogeographic zones into which south west Western Australia is divided, the others being the Transitional Rainfall Zone and the Low Rainfall Zone....
where relict
Relict
A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....
ual species are most common, whereas the others are restricted to the Transitional Rainfall Zone
Transitional Rainfall Zone
The Transitional Rainfall Zone is one of three biogeographic zones into which south west Western Australia is divided, the others being the High Rainfall Zone and the Low Rainfall Zone...
, where more recently evolved species are most common.
Distribution and habitat
An endangered species, B. cuneata occurs only over a 90 km (55 mi) range around PingellyPingelly, Western Australia
Pingelly is a town and shire located in the Wheatbelt region of Western Australia, from Perth via the Brookton Highway and Great Southern Highway. The town is also located on the Great Southern railway line...
and Quairading
Quairading, Western Australia
Quairading is a Western Australian town located in the Wheatbelt region. It is the seat of government for the Shire of Quairading.-History:The town was named for Quairading Spring, derived from a local Aboriginal word recorded in 1872 by surveyor Alexander Forrest. The first European settler in the...
, in 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...
. It favours deep yellow sand at elevations between 230 and 300 m (700–1000 ft), in 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...
habitat. It often grows in association with Banksia prionotes
Banksia prionotes
Banksia prionotes, commonly known as Acorn Banksia or Orange Banksia, is a species of shrub or tree of the genus Banksia in the family Proteaceae. It is native to the southwest of Western Australia and can reach up to 10 m in height. It can be much smaller in more exposed areas or in the...
and Xylomelum angustifolium
Xylomelum angustifolium
Xylomelum angustifolium is a tree species in the family Proteaceae, endemic to Western Australia. A mature Xylomelum angustifolium grows from 2 to 7 metres though trees up to 10m have been observed. Produces cream flowers between December and February though flowering can commence as early as...
.
Reports on the number of populations and individuals vary widely. A survey in 1982 reported 450 plants in five populations, with the largest population comprising 300 plants. In 1988, however, only four populations comprising 300 plants were found; surprisingly, only fifty plants could be found in the location where a population of 300 had previously been reported; yet there were no dead plants, and no evidence of disturbance. Since then the number of populations reported have ranged from 6 to 11, and reports of the total number of plants have ranged from 340 to 580.
Life cycle and ecology
Pollinated in the main by honeyeaters, the inflorescences appear from September to December. Prominent flowers, a red or pink colour, a straight style and a tubular perianth are features thought to promote pollination by birds.The structure of B. cuneata
Pollen-presenter
A pollen-presenter is an area on the tip of the pistil in flowers of plants of the family Proteaceae. In this family, the anthers are difficult of access for potential pollination vectors such as bees, birds and nectariferous mammals....
, suggests that autogamous self-fertilisation must be common. This is countered, however, by protandry
Dichogamy
Sequential hermaphroditism is a type of hermaphroditism that occurs in many fish, gastropods and plants. Here, the individual is born one sex and changes sex at some point in their life. They can change from a male to female , or from female to male...
: 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...
is released well before the pistil
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
becomes receptive; usually by the time the pistil becomes receptive most of the pollen has either been transferred, or has lost its viability. This strategy is effective against individual flowers fertilising themselves, but does nothing to prevent geitonogamy
Geitonogamy
Geitonogamy is the pollination of a flower with the pollen from another flower on the same flowering plant. In animal pollinated systems this is accomplished by a pollinator visiting multiple flowers on the same plant...
: fertilisation of flowers by different flowers on the same plant. Because of the way flowers are clustered together in heads, this must be quite common, although whether it results in successful fruit set is another matter: isozyme studies have observed "intense selection against homozygotes", a fairly common outbreeding strategy in plants that set lots of seed.
Assessments of the mating system
Mating system
A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to higher animals, it specifies which males mate with which females, under which circumstances; recognised animal mating systems include monogamy,...
of this species have found that 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 vary between populations. Populations in relatively intact bushland have high outcrossing rates, but those in more disturbed environments are both more inbred
Inbreeding
Inbreeding is the reproduction from the mating of two genetically related parents. Inbreeding results in increased homozygosity, which can increase the chances of offspring being affected by recessive or deleterious traits. This generally leads to a decreased fitness of a population, which is...
on average, and more variable. This has been attributed to a range of causes. Firstly, the higher density of disturbed populations leads to greater rates of mating between neighbouring plants, resulting in more genetic structure
Genetic structure
Genetic structure refers to any pattern in the genetic makeup of individuals within a population.In the absence of genetic structure, one can infer little to nothing about the genetic makeup of an individual by studying other members of the population...
and thus more effective selfing
Effective selfing model
The effective selfing model is a mathematical model that describes the mating system of a plant population in terms of the degree of self-fertilisation present....
. Secondly, disturbed populations usually lack an understorey
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
, and so cannot support a resident population of honeyeaters; instead, they rely upon occasional visitors for pollination. The greatly reduced pollination rates means fewer outcrossing fertilisations on average, leading to less selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
against inbred fertilisations; and the sporadic presence of pollinators leads to outcrossing variability.
No seed is set when pollinators are excluded
Pollinator exclusion experiment
Pollinator exclusion experiments are experiments used by ecologists to determine the effectiveness of putative plant pollination vectors. Essentially, certain pollinators are prevented from visiting certain flowers, and observations are then made on the which flowers develop seeds...
, indicating that seed set must be pollinator-limited. About 96% of fertilized follicles mature, and about 82% of seeds mature. These are very high numbers for Banksia, indicating that there are no problems with nutrient supply. This species produces an unusually high number of old flowerheads, or cones, per plant—typically more than 500. However there are an unusually low number of follicles per cone—often only one. Thus the number of follicles per plant ends up roughly average for a Banksia species.
Banksia cuneata lacks a 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...
, so plants are killed by bushfire. However, this species is strongly serotinous
Serotiny
Serotiny is an ecological adaptation exhibited by some seed plants, in which seed release occurs in response to an environmental trigger, rather than spontaneously at seed maturation. The most common and best studied trigger is fire, and the term serotiny is often used to refer to this specific case...
: seed is released only following a fire. Thus plants accumulate an aerial seed bank
Canopy seed bank
A canopy seed bank or aerial seed bank is the aggregate of viable seed stored by a plant in its canopy. Canopy seed banks occur in plants that postpone seed release for some reason....
in fire intervals, which is released all at once after a fire, ensuring population regeneration. The mechanism is a resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
that seals the follicles shut, preventing dehiscence
Dehiscence (botany)
Dehiscence is the opening, at maturity, in a pre-defined way, of a plant structure, such as a fruit, anther, or sporangium, to release its contents. Sometimes this involves the complete detachment of a part. Structures that open in this way are said to be dehiscent...
; the heat of a bushfire melts the resin, and the follicles open. Intense fires cause the immediate release of the seed and seed separator
Seed separator
A seed separator is a structure found in the follicles of some Proteaceae. These follicles typically contain two seeds, with a seed separator between them...
, but after cooler fires the seed separator often remains in place, blocking the follicle exit and preventing seed release. The wings on the seed separator are hygroscopic
Hygroscopy
Hygroscopy is the ability of a substance to attract and hold water molecules from the surrounding environment. This is achieved through either absorption or adsorption with the absorbing or adsorbing material becoming physically 'changed,' somewhat, by an increase in volume, stickiness, or other...
; they draw together when moistened, then reflex out again as they dry. Thus they lever themselves, and the seeds, out of the follicle over the course of one or more wet-dry cycles, ensuring that seed is released only after rain has fallen. The juvenile period for B. cuneata is around four years. Populations are very vulnerable to fire during this period, as fire will wipe out the entire population and there will be no seed from which it might recover. A model-based investigation found that the optimal fire interval for maximising population size over the medium term is around 15 years. More frequent fires reduce population size by killing adults before they have reached their full fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
. Less frequent fires reduce population size because there are fewer opportunities for seed dispersal and germination. However the optimal fire interval for minimising the risk of extinct in the long term is probably much longer.
B. cuneata is very unusual in apparently suffering no seed loss due to granivory
Seed predation
Seed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores feed on the seeds of plants as a main or exclusive food source, in many cases leaving the seeds damaged and not viable...
. In nearly all other species, burrowing insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
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 eat a large proportion of seeds, and birds cause further losses in breaking open cones in search of larvae to eat. The seed-eating insects are mostly species-specific, and it appears that no insect species has adapted to B. cuneata. Possible reasons for this are the very low seed counts, and the rarity of the species, both of which offer little incentive for adaptation to the species. There is also no evidence of granivores feeding on seed after it has fallen. As a result, this species has the highest rate of seed viability recorded for a Banksia species: in one study, 74% of all seed produced in the previous 12 years was viable. This was largely accounted for by seed under 9 years old, about 90% of which is viable. After the ninth year, viability is lost rapidly as the follicles decay and senescence
Senescence
Senescence or biological aging is the change in the biology of an organism as it ages after its maturity. Such changes range from those affecting its cells and their function to those affecting the whole organism...
sets in. Seed production itself starts very slowly. On average, plants aged between 5 and 12 years have about 18 seeds stored in their canopy. Storage increases exponentially, however, and 25-year old plants often have tens of thousands of seeds. Seed production probably never plateaus. In fact, by the time a plant is twenty years old it has accumulated such a great weight of cones that major branches begin to break away; and by the age of thirty, plants have broken branches more often than not. As plants age, branch breakage increasingly leads to plant death, and it is unlikely that any plants live to more than 45 years.
The high seed maturation and viability rates are offset, however, by an extremely low seedling survival rate. This is almost solely due to moisture stress. In one study, an estimated 17,100 viable seeds were released following an experimental fire. Fewer than 5% of them germinated, and only eleven plants survived the first summer drought. The last plants to die were in depressions, in shaded areas or amongst leaf litter; and the eleven survivors were all on road shoulders, where they benefited from road runoff
Surface runoff
Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
and a 3 cm (1.2 in) thick mulch
Mulch
In agriculture and gardening, is a protective cover placed over the soil to retain moisture, reduce erosion, provide nutrients, and suppress weed growth and seed germination. Mulching in gardens and landscaping mimics the leaf cover that is found on forest floors....
of pisolitic
Pisolite
A pisolite is a sedimentary rock made of pisoids, which are concretionary grains - often of calcium carbonate, but sometimes of rarer minerals - which resemble ooids but are always more than 2 mm in diameter. These grains are approximately spherical and have concentric layers reaching...
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...
. The inevitable conclusion is that seedling survival is primarily determined by water availability.
Conservation
Banksia cuneata was declared critically endangeredEndangered 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...
after a 1982 survey found only five populations comprising about 450 plants. The largest population, consisting of around 300 plants, was on a conservation reserve, but all others were on road verges, and contained only 50–70 plants each. However, since then more plants have been located, and populations have been found to be gradually increasing in response to a number of conservation
Conservation biology
Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction...
measures including fencing and baiting of rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s. In recognition of its slight recovery, it is now considered endangered but no longer critically so.
In April 1987, Western Australia's Department of Environment and Conservation burnt part of one population in an experimental regeneration fire. The mature plants were killed, and the seedlings that volunteer
Volunteer (botany)
In gardening and botanical terminology, a volunteer is a plant that grows on its own, rather than being deliberately planted by a farmer or gardener...
ed did not survive the summer drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
. A Matchstick Banksia Recovery Team was established in 1995, and over time they succeeded in establishing a large number of seedlings. A large adult population was destroyed by bushfire in 1996, causing further concern, but this was followed by the recruitment of large numbers of seedlings.
Threats to B. cuneata include land clearing, which leads to direct plant loss and population fragmentation, grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
pressure, competition from exotic weeds, changes to the fire regime
Fire regime
A fire regime is the pattern, frequency and intensity of the bushfires and wildfires that prevails in an area. It is an integral part of fire ecology, and renewal for certain types of ecosystems. If fires are too frequent, plants may be killed before they have matured, or before they have set...
, and encroaching salinity
Salinity in Australia
Soil salinity and dryland salinity are two problems degrading the environment of Australia. Salinity is a concern in most states, but especially in the south-west of Western Australia....
. The Banksia Atlas
The Banksia Atlas
The Banksia Atlas is an atlas that documents the ranges, habitats and growth forms of various species and other subgeneric taxa of Banksia, an iconic Australian wildflower genus...
survey found one population to be on the side of a road; the plants were aging with no new seedlings noted, and the site was weed-infested. A large part of the surviving populations are on private land, and depend on good relationships with local landowners. Many have obliged by fencing off areas and restricting entry of rabbits. There has been some attempt by CALM to translocate populations away from hazardous areas; these have met with some success, helped with watering in the first year.
Land clearing
Even before the extensive clearing of the Wheatbelt in the 1930s, B. cuneata must have had a highly fragmented distribution, since the deep yellow sand favoured by the species occurs only in patches, and makes up only 10 to 15% of the area. Around 93% of the land has now been cleared of native vegetation, with the remaining 7% occurring in remnants of various sizes. Thus land clearing must have further fragmented an already fragmented population, as well as greatly reduced the number of individual plants.Protection of genetic diversity
Levels of genetic diversityGenetic diversity
Genetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary....
within individual populations of B. cuneata are unusually high for a rare and endangered species, but the populations fall into two genetically distinct groups. These are separated not by geographical distance but by the Salt River
Salt River (Western Australia)
Salt River is a saline river system in south-west Western Australia. It arises from a chain of salt lakes in the vicinity of Corrigin, flowing northward nearly to Bruce Rock then west and south-west past Quairading, before discharging into the Yenyening Lakes northeast of Brookton...
, an ephemeral
Ephemeral
Ephemeral things are transitory, existing only briefly. Typically the term is used to describe objects found in nature, although it can describe a wide range of things....
saline river system that provides a habitat unsuitable for both B. cuneata and the birds that pollinate it. It thus functions as a barrier to the exchange of genetic material, allowing populations on different sides of the river to diverge
Genetic divergence
Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes through time, often after the populations have become reproductively isolated for some period of time...
through genetic drift
Genetic drift
Genetic drift or allelic drift is the change in the frequency of a gene variant in a population due to random sampling.The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces...
. The implication for conservation is that effort should be invested on both sides of the river in order to conserve as much genetic diversity as possible. It was suggested that one large population from each population group would probably be adequate. More recently, however, a model-based risk analysis found that the population size required to reduce extinction risk to acceptable levels is more than ten times the current population size. This leads to the conclusion that all populations, and all available habitat, should be protected.
Disease
Phytophthora cinnamomiPhytophthora 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...
dieback has not been identified as a threat to this species, but testing has found it to be highly susceptible; in one study it exhibited the highest susceptibility of 49 Banksia species studied, with 80% of plants dead within 96 days of inoculation with the disease, and 100% dead within a year.
Climate change
The survival of this species is tied closely to rainfall because of the susceptibility of seedlings to drought. It is thus especially vulnerable to the effects of climate changeClimate 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...
. This was recognised as early as 1992, when it was noted that winter rainfall in the Quairading region had been falling by about 4% per decade, and that a continuation of this trend may reduce the species' distribution. Recently, a more thorough assessment of the potential impact of climate change on this species found that severe change is likely to lead to extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
, and mild change to a reduction of its range by 80% by 2080. However, there may not be any range reduction at all under mid-severity climate change, depending on how effectively this species can migrate into newly habitable areas.
Cultivation
Propagation is by seed, although these are hard to obtain. Seeds do not require any treatment before sowing, and take around 23 days to germinateGermination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
. Cutting
Cutting
Cutting is the separation of a physical object, or a portion of a physical object, into two portions, through the application of an acutely directed force. An implement commonly used for cutting is the knife or in medical cases the scalpel...
s yield unpredictable results. The plant itself prefers a deep, sandy, well-drained soil with a pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
of 6.0–7.0. It requires full sun, but some protection from the wind is recommended, as this is a fast-growing plant with spindly branches that are easily damaged by wind. A more compact form can be obtained by pruning the top quarter each year. This species has little appeal to the cut flower industry
Floriculture
Floriculture, or flower farming, is a discipline of horticulture concerned with the cultivation of flowering and ornamental plants for gardens and for floristry, comprising the floral industry...
, because of its prickly foliage, and its tendency to drip nectar.
Ironically, given its conservation status, Kingsley Dixon of Kings Park and Botanic Garden
Kings Park, Western Australia
Kings Park is a park located on the western edge of Perth, Western Australia central business district. The park is a mixture of grassed parkland, botanical gardens and natural bushland on Mount Eliza with two thirds of the grounds conserved as native bushland. With panoramic views of the Swan...
suggested that it may have weed potential: the species was trialled as a cut flower crop on land north of Moore River, and seedlings were noted afterwards.
Cultural references
Banksia cuneata has been adopted as the floral emblem of the Shire of QuairadingShire of Quairading
The Shire of Quairading is a Local Government Area in the Wheatbelt region of Western Australia, about east of the state capital, Perth. The Shire covers an area of , and its seat of government is the town of Quairading.-History:...
, and has been incorporated into the shire logo. There is a park named Cuneata Park in the town of Quairading
Quairading, Western Australia
Quairading is a Western Australian town located in the Wheatbelt region. It is the seat of government for the Shire of Quairading.-History:The town was named for Quairading Spring, derived from a local Aboriginal word recorded in 1872 by surveyor Alexander Forrest. The first European settler in the...
.