Banksia attenuata
Encyclopedia
Banksia attenuata, commonly known as the candlestick banksia or slender banksia, is a species
of plant
in the proteaceae
family. Commonly a tree, it reaches 10 m (35 ft) high, but is often a shrub
in dryer areas 0.4 to 2 m (1–7 ft) high. It has long narrow serrated leaves and bright yellow inflorescence
s, or flower spikes, held above the foliage, which appear in spring and summer. The flower spikes age to grey and swell with the development of the woody follicles
. It is found across much of the southwest
of Western Australia
, from north of Kalbarri National Park
down to Cape Leeuwin
and across to Fitzgerald River National Park
.
John Lindley
had named material collected by James Drummond
Banksia cylindrostachya in 1840, but this proved to be the same as the species named Banksia attenuata by Robert Brown
30 years earlier in 1810, and thus Brown's name took precedence. Within the genus Banksia
, the close relationships and exact position of B. attenuata is unclear.
The candlestick banksia is pollinated by and provides food for a wide array of vertebrate and invertebrate animals in summer months. Several species of honeyeater
visit the flower spikes, as does the honey possum
, which has an important role as a pollinator. It regenerates from bushfire by regrowing from its woody base known as a lignotuber
, or from epicormic buds within its trunk. Plants may have a lifespan of 300 years. It has been widely used as a street tree and for amenities
planting in urban Western Australia, though its large size generally precludes use in small gardens. A dwarf form is commercially available in nurseries.
0.4 to 2 m (1–7 ft) tall. Both forms occur in the vicinity of Hill River
but there is otherwise a marked demarcation. In the Wheatbelt and east of the Stirling Range
, it is a stunted tree. Tree forms have a solid trunk, generally wavy or bent, with 1–2 cm (0.4–0.8 in) thick crumbly orange-grey bark which is a red-brown underneath. It regenerates from fire via lignotuber
or epicormic buds from its fire-tolerant trunk. It has long narrow shiny green linear leaves 4 to 27 cm (1.6–11 in) long and 0.5 to 1.6 cm (0.2–0.7 in) wide. The leaf margins have v- or u-shaped serrations along their length. The new growth is a pale grey-green, and occurs mainly in the late spring and summer, often after flowering. The brilliant yellow inflorescence
s (flower spikes) occur from spring into summer and are up 5 cm (2 in) wide and up to 25–30 cm (10–12 in) tall. They are made up of many small individual flowers; a study at Mount Adams 330 km (200 mi) north of Perth
revealed a count of 1933 (± a standard error
of 88) flowers per inflorescence, and another in the Fitzgerald River National Park
yielded a count of 1720 (± 76) flowers. Anthesis
proceeds up the flower spike over about 10 to 20 days, and is asynchronous. That is, a plant produces flower spikes over a several week period and will thus have spikes at different stages of development over the flowering season. Often bright green in bud stage, they are terminal, occurring at the ends of one- to three-year old branches, and displayed prominently above the foliage. The smell of the open flowers has been likened to a peppery Shiraz wine. Over time, the spikes fade to brown and then grey, and the individual flowers shrivel and lie against the spikes. This coincides with the development of dark furry oval follicles
, which measure 2–3.5 cm (0.8–1.4 in) long, 1–1.5 cm (0.4–0.6 in) high, and 1.4–2 cm (0.5–0.8 in) wide. However, only a very small percentage (0.1%) of flowers develop into follicles; the field study at Mount Adams yielded a count of 3.6 ± 1.2 per cone. The follicles develop and mature over seven to eight months, from February to December, while seed development occurs over four months from September to December.
from King George Sound
in December 1801, and published by him in 1810. The specific epithet is the Latin
adjective attenuatus "narrowed", and refers to the leaves narrowing towards the base. The species has had a fairly uneventful taxonomic
history. It has only two synonyms, and no subspecies
or varieties have been published; George reviewed the variation in form in the species, and felt that the tree and shrub forms differed only in size and hence were not distinct enough to represent separate taxa. In 1840, John Lindley
published a putative new species, Banksia cylindrostachya, in his A Sketch of the Vegetation of the Swan River Colony
; this has now be shown to be a taxonomic synonym of B. attenuata. In 1891, Otto Kuntze
made a failed attempt to transfer Banksia to the new generic name Sirmuellera. In the process he published the name Sirmuellera attenuata, which is now considered a nomenclatural synonym of B. attenuata. Common name
s include slender banksia, candle banksia and candlestick banksia. Piara (alternately spelled biara) is an aboriginal
name from the Melville
region of Perth.
The relationships of Banksia attenuata within the genus are unclear. When Carl Meissner
published his infrageneric arrangement
of Banksia in 1856, he placed B. attenuata in section Eubanksia
because its inflorescence is a spike rather than a domed head, and in series Salicinae
, a large series that is now considered quite heterogeneous. This series was discarded in the 1870 arrangement
of George Bentham
; instead, B. attenuata was placed in section Cyrtostylis, a group of species which did not fit easily into one of the other sections.
In 1981, Alex George
published a revised arrangement that placed B. attenuata in the subgenus Banksia
because of its flower spike, section Banksia
because its styles are straight rather than hooked, and the series Cyrtostylis
, a large and rather heterogenous series of twelve species. He conceded its large emarginate cotyledon
s (having a notch in their apex) were quite different from other members, and that it had similarities in flower architecture to another anomalous member B. elegans
. He felt B. attenuata to have affinities to B. lindleyana
and B. media
.
George's arrangement remained current until 1996, when Kevin Thiele
and Pauline Ladiges published an arrangement
informed by a cladistic
analysis of morphological
characteristics. They calculated B. attenuata to lie at the base of a large B. attenuata – B.ashbyi clade
, but conceded further work was needed before its relationships could be determined, and left it as incertae sedis
(i.e. Its exact placement is unclear.). Questioning the emphasis on cladistics in Thiele and Ladiges' arrangement, George published a slightly modified version of his 1981 arrangement in his 1999 treatment of Banksia for the Flora of Australia
series of monograph
s. To date, this remains the most recent comprehensive arrangement. The placement of B. attenuata in George's 1999 arrangement
may 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 attenuata resolves as a basal member of and next closest relative, or 'sister', to a clade containing B. elegans and, within that, a monophyletic
B. subg. Isostylis. An Eocene
fossil cone named Banksia archaeocarpa
, around 50 million years old, resembles that of B. attenuata.
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 cotyledons; 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. attenuata is placed in B. subg. Banksia.
of Western Australia
, from Kalbarri National Park
and the Murchison River
(with an outlying population in Zuytdorp National Park) southwards right to the southwestern corner of the state at Augusta
and Cape Leeuwin
, and then eastwards across the south to the western edge of Fitzgerald River National Park
. Along the eastern border northwards it is found at Lake Grace, Lake Magenta north of Jerramungup
, and the Wongan Hills
. It is restricted to various sandy soils, including white, yellow or brown sands, and sand over either laterite
or limestone
. It forms an important component of open Eucalyptus
woodland as a dominant or understory
tree or tall shrub. To the north, it is a shrubby component of shrubland
. It does not grow on heavy (clay-based) soils, and is hence only found in sandy pockets. Within open woodland, it is found alongside B. menziesii
, B. ilicifolia
, B. prionotes
, Allocasuarina fraseriana
, Eucalyptus marginata, or E. gomphocephala
. The annual rainfall within its distribution varies from 300 to 900 mm (12–36 in).
Like many plants in south-west Western Australia, B. attenuata is adapted to an environment in which bushfire events are relatively frequent. Most Banksia species can be placed in one of two broad groups according to their response to fire: reseeders are killed by fire, but fire also triggers the release of their canopy seed bank
, thus promoting recruitment of the next generation; resprouter
s survive fire, resprouting from a lignotuber
or, more rarely, epicormic buds
protected by thick bark. Bearing epicormic buds and a lignotuber, B. attenuata is one of the latter group, with follicles that may open spontaneously or by fire. It is moderately serotinous
, storing only one tenth the number of seeds in its seed bank as the reseeding B. hookeriana which it coexists with on sand dunes in scrub at Eneabba
north of Perth. Even then, many of its follicles do not release seed after a fire, but instead after successive autumn rains. An experiment simulating wet weather following a fire saw a series of Banksia attenuata cones with follicles subjected to twice weekly immersions in water after being heated in a ring Bunsen
flame to around 500–600 °C (930–1100 °F) for two minutes. Cones that had been exposed to water for more weeks had more seed released from follicles over time; around 40% released at three weeks, increasing steadily to almost 90% at ten weeks, compared with a series of controls
(which were kept dry) of which fewer than 10% of seed released. Thus, the seed remains in the follicles until successive rains result in seed dispersal in the wetter winter (instead of dryer summer), increasing the chance of survival. After the follicle is split, the seed and separator are exposed to the elements. The wings of the woody separator are hygroscopic, and move together when wet, and spread and curl apart when dry. The seed is gradually drawn out by the movement with each wetting. Once released, seed germinates at temperatures between 15 and 20 °C (60–70 °F) to optimise timing with autumn and winter rains and hence maximise chance of survival. Still, many seedlings die off in the hot and dry summer months. Seedling survival for the species is lower than for banksias which regenerate by seeding over time. Despite this, the longevity of mature plants allows for maintenance of population until favourable years enable better survival of young plants. As they mature, plants are less likely to perish, and estimated to live for 300 years or more. Analyzing the seed bank and longitudinal results over fifteen years on the Eneabba sandplain showed that B. attenuata would become more abundant over time with fire intervals averaging between 6 and 20 years, peaking with intervals around 10 to 12 years, compared with longer intervals for the reseeders B. hookeriana and B. prionotes. Placed against its rivals, B. attenuata would be dominant between 8 and 10 or 11 years, but at longer intervals is outcompeted by B. hookeriana. Variability in the timing between fires allows all three species to coexist. Exaggerated good and bad weather conditions favours B. attenuata over the reseeding species, which suffer more.
Despite having relatively heavy seed, seed from Banksia attenuata has a high rate of long distance dispersal. A genetic study of populations in Eneabba showed that over 5% of plants had originated up to 2.6 km (1.6 mi) away (similar rates to Banksia hookeriana, the seed of which only weighs half as much). The mechanism for this is unclear, although Byron Lamont has proposed the Short-billed Black Cockatoo (Calyptorhynchus latirostris) as a vector; the species seeks out Banksia attenuata cones after bushfire, possibly because the large seeds and greater chance of grubs in the cone make them more nutritious. Flowering has been recorded one to two years after a bushfire.
Like many members of the family Proteaceae, Banksia attenuata is an obligate outcrossing
species. Self-incompatible
, inflorescences require pollinators to be fertilised and produce seed. A genetic study of seed collected near Jandakot published in 1980 showed obligate outcrossing. A field study in the Fitzgerald River National Park where inflorescences were enclosed in mesh fine enough to keep out vertebrates and invertebrates as small as the honey bee (Apis mellifera) showed that follicles still developed, indicating that small invertebrates were able to cross-pollinate the species. Banksia attenuata flowers are visited by the colletid
bee Hylaeus globuliferus and bees of the genus Euhesma
. Other pollinating invertebrates recorded include ants and dragonflies. An analysis of the invertebrate population found in the canopy of Banksia woodland found that mites and ticks (acari), beetles (coleoptera) and ants, bees and wasps (hymenoptera
) predominated overall, with the three orders also the most common on B. attenuata along with thrips (thysanoptera). Lower overall numbers of invertebrates on Banksia species were thought to be related to the presence of insectivorous birds.
Many bird species were recorded by the national Banksia Atlas survey, including the New Holland Honeyeater
(Phylidonyris novaehollandiae) , Brown Honeyeater
(Lichmera indistincta), Singing Honeyeater
(Lichenostomus virescens), Western Spinebill
(Acanthorhynchus superciliosus), Twenty-eight Parrot
(Barnardius zonarius semitorquatus) and Red-tailed Black Cockatoo
(Calyptorhynchus banksii). Black Cockatoos have been observed feeding upon the seed of B. attenuata, although it is not clear which species of black cockatoo was observed, the Short-billed or Long-billed Black Cockatoo (Calyptorhynchus baudinii). At a site near Jandakot, Short-billed Black Cockatoos were observed selecting immature infructescences which bore signs of infestation by the weevil Alphitopis nivea, the larvae of which tunnel in banksia spikes and eat the seed. They extract the larvae and drop the cones.
A 1978 field study conducted around Albany
found the honey possum
(Tarsipes rostratus) was a major pollinator of Banksia attenuata, both feeding directly on the pollen and drinking the nectar. The flower structure is suited to passing pollen onto the possum as it feeds, unlike honeyeaters whose bills are too long for this to occur readily. Coupled with the flower spike's musky odour, these findings suggest Banksia attenuata is highly adapted to be pollinated primarily by this mammal species. Furthermore, Petroc Sumner and colleagues have investigated the cone
photoreceptor cells of honey possums and compared them with the colour changes of B. attenuata. They found that the possum is trichromatic (like humans and possibly many marsupials) and propose that its L (long wavelength) cones help it discern B. attenuata flower spikes, and the M (or medium wavelength) cones could help it distinguish ripe inflorescences with nectar from recently finished spikes (a difficult task for human vision). There is some evidence for other mammals as pollinators; B. attenuata-like pollen was recovered from museum skins of dunnart
s (Sminthopsis spp.) and pygmy possums (Cercartetus
spp.), and the sugar glider
(Petaurus breviceps) visited flower spikes in captivity.
Seventeen species from several orders
of slime molds (myxomycetes) have been isolated from the bark of Banksia attenuata. Over half (nine) were from the order Stemonitales, and Echinosteliales and Liceales
were also common. The abundance of the first two orders may be due to the acidity of the bark. Another order, the Physarales, was unusually rare—other studies have demonstrated that the order is typically abundant on the bark of various species of tree around the world.
All banksias have developed proteoid or cluster roots in response to the nutrient-poor conditions of Australian soils (particularly lacking in phosphorus
). These have been measured in Eneabba extending to a depth of 15 cm (6 in) below the soil surface. The plant develops masses of fine lateral roots which form a mat-like structure underneath the soil surface, and enable it to extract nutrients as efficiently possible out of the soil. A study of three co-occurring species in Banksia woodland in southwestern Australia—Banksia menziesii, B. attenuata and B. ilicifolia—found that all three develop fresh roots in September after winter rainfall, and that the bacteria populations associated with the root systems of B. menziesii differ from the other two, and that they also change depending on the age of the roots. Another study on root architecture of Banksia hookeriana, B. menziesii and B. attenuata found the overall structure of all three to be similar, with proteoid mats more active and growing in wetter months (winter-spring). Plants send out several sinker roots which descend to reach the water table
, and the original tap root may or may not have died off. Along with B. amenziesii, B. attenuata is a facultative phreatophyte. The two species are less strictly tied to the water table
and hence able to grow in a wider variety of places within Banksia woodland habitat around Perth than the co-occurring B. ilicifolia
and B. littoralis
. A study at a rehabilitation site on a sand mine north of Perth found that the broadleaved species B. attenuata and B. hookeriana were harder to establish than the fine-leaved B. leptophylla
there, due to increased impedance of the disturbed soil. Analysis of native plant species at a remnant of banksia woodland in suburban Perth which had been invaded by two herbaceous weed species (Ehrharta calycina
and Pelargonium capitatum
) found increased phosphorus
levels in native foliage. Although B. attenuata leaves did not have increased phosphorus, they did have reduced levels of manganese
—an element which is absorbed into the plant by its proteoid roots, the formation of which can be inhibited by raised levels of phosphorus.
In a 1985 study inoculating cultivated plants, Banksia attenuata showed moderate to high susceptibility to Phytophthora cinnamomi
dieback; and at least some field and cultivation evidence points to it being highly susceptible. P. cinnamomi spreads from plant to plant via lateral roots, advancing at a rate of around a metre a year. The symptoms of infection in Banksia attenuata include yellowing of the leaves in the tree crown, and lesions at the base of the trunk. The red healthy roots become discoloured brown. A study of Banksia attenuata woodland 400 km (250 mi) southeast of Perth across 16 years and following a wave of P. cinnamomi infestation showed that B. attenuata populations still existed but were significantly reduced in diseased areas. Injecting a solution of phosphite
into the trunks of affected B. attenuata trees at a disease front in Banksia woodland can delay morbidity from dieback for five years. Injecting and spraying phosphite also reduces the rate of spread of a dieback front for around five years. A bushfire did not influence this slowing. A 2003 study found that drenching the soil with 0.50 mM benzoic acid
significantly reduced the size of P. cinnamomi lesions. Research into dieback in Western Australia has identified a new species, P. multivora, isolated from ailing eucalypts and B. attenuata in 2009.
The well-displayed bright yellow spikes are an attractive feature, with shrubby dwarf forms more versatile horticulturally. All forms of Banksia attenuata require good drainage, sandy soil and a sunny position to do well, with a pH
between 5.5 and 7.0. They are sensitive to dieback
, and do not fare well in humid climates. Seeds do not require any treatment, and take 16 to 49 days to germinate. Seedlings are highly vulnerable to damping off
. Plants take from four to six years to flower from seed. There has been little success with other methods of improving adaptability to humid climates such as grafting
.
Flower spikes in late bud are used in the cut flower industry, primarily in Western Australia.
Aboriginal
people placed the flower spike in a paperbark-lined hole filled with water to make a sweet drink
. Both this species and B. aemula
have been credited with the inspiration behind May Gibbs
' Big Bad Banksia Men
; this species was familiar to Gibbs in her childhood and likely gave her the initial inspiration, although the depictions resemble the latter species. Artist Marianne North
produced a highly regarded painting of B. attenuata during her stay in Australia in 1880–81.
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 plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
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. Commonly a tree, it reaches 10 m (35 ft) high, but is often a 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...
in dryer areas 0.4 to 2 m (1–7 ft) high. It has long narrow serrated leaves and bright yellow 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 spikes, held above the foliage, which appear in spring and summer. The flower spikes age to grey and swell with the development of the woody 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....
. It is found across much of 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
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...
, from north of Kalbarri National Park
Kalbarri National Park
Kalbarri National Park is located north of Perth. The major geographical features of the park include the Murchison River gorge which runs for nearly 80 kilometres on the lower reaches of the Murchison River...
down to Cape Leeuwin
Cape Leeuwin
Cape Leeuwin is the most south-westerly mainland point of the Australian Continent, in the state of Western Australia.A few small islands and rocks, the St Alouarn Islands, extend further to the south. The nearest settlement, north of the cape, is Augusta. South-east of Cape Leeuwin, the coast...
and across to Fitzgerald River National Park
Fitzgerald River National Park
Fitzgerald River National Park is a national park in Western Australia , southeast of Perth, in the Shire of Ravensthorpe and the Shire of Jerramungup....
.
John Lindley
John Lindley
John Lindley FRS was an English botanist, gardener and orchidologist.-Early years:Born in Catton, near Norwich, England, John Lindley was one of four children of George and Mary Lindley. George Lindley was a nurseryman and pomologist and ran a commercial nursery garden...
had named material collected by James Drummond
James Drummond (botanist)
James Drummond was a botanist and naturalist who was an early settler in Western Australia.-Early life:...
Banksia cylindrostachya in 1840, but this proved to be the same as the species named Banksia attenuata by 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...
30 years earlier in 1810, and thus Brown's name took precedence. Within the genus 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...
, the close relationships and exact position of B. attenuata is unclear.
The candlestick banksia is pollinated by and provides food for a wide array of vertebrate and invertebrate animals in summer months. Several species of 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...
visit the flower spikes, as does the honey possum
Honey Possum
The honey possum or tait, its Native Australian name or noolbenger is a tiny Australian marsupial weighing just seven to eleven grams for the male, and eight to sixteen grams for the female—about half the weight of a mouse. Their physical size ranges from a body length of between 6.5 –...
, which has an important role as a pollinator. It regenerates from bushfire by regrowing from its woody base known as 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...
, or from epicormic buds within its trunk. Plants may have a lifespan of 300 years. It has been widely used as a street tree and for amenities
Amenity
In real property and lodging, amenities are any tangible or untangible benefits of a property, especially those that increase its attractiveness or value or that contribute to its comfort or convenience...
planting in urban Western Australia, though its large size generally precludes use in small gardens. A dwarf form is commercially available in nurseries.
Description
Banksia attenuata is generally encountered as a tree up to 10 m (35 ft) tall. In the north of its range as the climate becomes warmer and dryer, it is often a stunted multistemmed shrubShrub
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...
0.4 to 2 m (1–7 ft) tall. Both forms occur in the vicinity of Hill River
Hill River (Western Australia)
Hill River is a river and town in the Wheatbelt region of Western Australia. At the 2006 census, Hill River had a population of 134.The headwaters of the river below Dinner Hill approximately East of Badgingarra then flows in a westerly direction crossing the Brand Highway just North of...
but there is otherwise a marked demarcation. In the Wheatbelt and east of 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...
, it is a stunted tree. Tree forms have a solid trunk, generally wavy or bent, with 1–2 cm (0.4–0.8 in) thick crumbly orange-grey bark which is a red-brown underneath. It regenerates from fire via 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...
or epicormic buds from its fire-tolerant trunk. It has long narrow shiny green linear leaves 4 to 27 cm (1.6–11 in) long and 0.5 to 1.6 cm (0.2–0.7 in) wide. The leaf margins have v- or u-shaped serrations along their length. The new growth is a pale grey-green, and occurs mainly in the late spring and summer, often after flowering. The brilliant yellow 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 (flower spikes) occur from spring into summer and are up 5 cm (2 in) wide and up to 25–30 cm (10–12 in) tall. They are made up of many small individual flowers; a study at Mount Adams 330 km (200 mi) north of Perth
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
revealed a count of 1933 (± a standard error
Standard error (statistics)
The standard error is the standard deviation of the sampling distribution of a statistic. The term may also be used to refer to an estimate of that standard deviation, derived from a particular sample used to compute the estimate....
of 88) flowers per inflorescence, and another in the Fitzgerald River National Park
Fitzgerald River National Park
Fitzgerald River National Park is a national park in Western Australia , southeast of Perth, in the Shire of Ravensthorpe and the Shire of Jerramungup....
yielded a count of 1720 (± 76) flowers. 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...
proceeds up the flower spike over about 10 to 20 days, and is asynchronous. That is, a plant produces flower spikes over a several week period and will thus have spikes at different stages of development over the flowering season. Often bright green in bud stage, they are terminal, occurring at the ends of one- to three-year old branches, and displayed prominently above the foliage. The smell of the open flowers has been likened to a peppery Shiraz wine. Over time, the spikes fade to brown and then grey, and the individual flowers shrivel and lie against the spikes. This coincides with the development of dark furry oval 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....
, which measure 2–3.5 cm (0.8–1.4 in) long, 1–1.5 cm (0.4–0.6 in) high, and 1.4–2 cm (0.5–0.8 in) wide. However, only a very small percentage (0.1%) of flowers develop into follicles; the field study at Mount Adams yielded a count of 3.6 ± 1.2 per cone. The follicles develop and mature over seven to eight months, from February to December, while seed development occurs over four months from September to December.
Taxonomy
Banksia attenuata was first collected by Robert BrownRobert Brown (botanist)
Robert Brown was a Scottish botanist and palaeobotanist who made important contributions to botany largely through his pioneering use of the microscope...
from King George Sound
King 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 December 1801, and published by him in 1810. The specific epithet is 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...
adjective attenuatus "narrowed", and refers to the leaves narrowing towards the base. The species has had a fairly uneventful taxonomic
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
history. It has only two synonyms, and no subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
or varieties have been published; George reviewed the variation in form in the species, and felt that the tree and shrub forms differed only in size and hence were not distinct enough to represent separate taxa. In 1840, John Lindley
John Lindley
John Lindley FRS was an English botanist, gardener and orchidologist.-Early years:Born in Catton, near Norwich, England, John Lindley was one of four children of George and Mary Lindley. George Lindley was a nurseryman and pomologist and ran a commercial nursery garden...
published a putative new species, Banksia cylindrostachya, in his A Sketch of the Vegetation of the Swan River Colony
A Sketch of the Vegetation of the Swan River Colony
A Sketch of the Vegetation of the Swan River Colony, also known by its standard botanical abbreviation Sketch Veg. Swan R., is an 1839 article by John Lindley on the flora of the Swan River Colony...
; this has now be shown to be a taxonomic synonym of B. attenuata. 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...
made a failed attempt to transfer Banksia to the new generic name Sirmuellera. In the process he published the name Sirmuellera attenuata, which is now considered a nomenclatural synonym of B. attenuata. 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 include slender banksia, candle banksia and candlestick banksia. Piara (alternately spelled biara) is an aboriginal
Australian Aborigines
Australian Aborigines , also called Aboriginal Australians, from the latin ab originem , are people who are indigenous to most of the Australian continentthat is, to mainland Australia and the island of Tasmania...
name from the Melville
Melville, Western Australia
Melville is a suburb of Perth, Western Australia located within the likewise named City of Melville....
region of Perth.
The relationships of Banksia attenuata within the genus are unclear. When 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...
published his infrageneric arrangement
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...
of Banksia in 1856, he placed B. attenuata in section Eubanksia
Banksia sect. Eubanksia
Banksia sect. Eubanksia is an obsolete section of Banksia. There have been two circumscriptions, one of which is synonymous with the recently abandoned B. subg. Banksia sensu Alex George, the other having no modern equivalent....
because its inflorescence is a spike rather than a domed head, and in series Salicinae
Banksia ser. Salicinae
Banksia ser. Salicinae is a valid botanic name for a series of Banksia. First published by Carl Meissner in 1856, the name has had three circumscriptions.-According to Meissner:...
, a large series that is now considered quite heterogeneous. This series was discarded in the 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...
of 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 :...
; instead, B. attenuata was placed in section Cyrtostylis, a group of species which did not fit easily into one of the other sections.
In 1981, 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 revised arrangement that placed B. attenuata in the 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...
because of its flower spike, section Banksia
Banksia sect. Banksia
Banksia 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...
because its styles are straight rather than hooked, and the series Cyrtostylis
Banksia ser. Cyrtostylis
Banksia ser. Cyrtostylis is a valid botanic name for a taxonomic series within the plant genus Banksia. First published at sectional rank by George Bentham in 1870, it was demoted to a series by Alex George in 1981. The name has had three circumscriptions.-According to Bentham:Bentham published B....
, a large and rather heterogenous series of twelve species. He conceded its large emarginate 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 (having a notch in their apex) were quite different from other members, and that it had similarities in flower architecture to another anomalous member B. elegans
Banksia elegans
The Elegant Banksia is a species of shrub or small tree in the plant genus Banksia. It occurs only over a 65 square kilometre area north and west of Eneabba, Western Australia.-Ecology:...
. He felt B. attenuata to have affinities to B. lindleyana
Banksia lindleyana
Banksia lindleyana, commonly known as the Porcupine Banksia, is a species of woody shrub in the genus Banksia of the family Proteaceae. It generally grows as a small shrub to 1 m high with long narrow serrated leaves, and bright yellow oval or round inflorescences...
and B. media
Banksia media
The Southern Plains Banksia , also known as Golden Stalk Banksia, is a species of shrub in the plant genus Banksia. It occurs on the south coast of Western Australia between Albany and Israelite Bay, where it is a common plant....
.
George's arrangement remained current until 1996, when 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 an 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...
informed by a 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 morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
characteristics. They calculated B. attenuata to lie at the base of a large B. attenuata – B.ashbyi 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...
, but conceded further work was needed before its relationships could be determined, and left it as incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
(i.e. Its exact placement is unclear.). Questioning the emphasis on cladistics in Thiele and Ladiges' arrangement, George published a slightly modified version of his 1981 arrangement in his 1999 treatment of Banksia 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 of monograph
Monograph
A monograph is a work of writing upon a single subject, usually by a single author.It is often a scholarly essay or learned treatise, and may be released in the manner of a book or journal article. It is by definition a single document that forms a complete text in itself...
s. To date, this remains the most recent comprehensive arrangement. The placement of B. attenuata in George's 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...
may 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...
- B. sect. 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...
- B. ser. CyrtostylisBanksia ser. CyrtostylisBanksia ser. Cyrtostylis is a valid botanic name for a taxonomic series within the plant genus Banksia. First published at sectional rank by George Bentham in 1870, it was demoted to a series by Alex George in 1981. The name has had three circumscriptions.-According to Bentham:Bentham published B....
- B. mediaBanksia mediaThe Southern Plains Banksia , also known as Golden Stalk Banksia, is a species of shrub in the plant genus Banksia. It occurs on the south coast of Western Australia between Albany and Israelite Bay, where it is a common plant....
- B. praemorsaBanksia praemorsaThe Cut-leaf Banksia is a species of shrub or tree in the plant genus Banksia. It occurs in a few isolated populations on the south coast of Western Australia between Albany and Cape Riche. Seeds do not require any treatment, and take 30 to 49 days to germinate.-References:...
- B. epicaBanksia epicaBanksia epica is a shrub that grows on the south coast of Western Australia. A spreading bush with wedge-shaped serrated leaves and large creamy-yellow flower spikes, it grows up to 3½ metres high. It is known only from two isolated populations in the remote south east of the state, near the...
- B. pilostylisBanksia pilostylisThe Marsh Banksia is a species of shrub in the plant genus Banksia. It occurs on the south coast of Western Australia around Esperance. Seeds do not require any treatment, and take 18 to 49 days to germinate.-External links:...
- B. attenuata
- B. ashbyiBanksia ashbyiThe Ashby's Banksia is a species of shrub in the plant genus Banksia. It occurs in heath and spinifex country along the coast of Western Australia between Geraldton and Exmouth.-Description:...
- B. benthamianaBanksia benthamianaBentham's Banksia is a species of shrub or tree in the plant genus Banksia. It occurs in scattered populations in the Wheatbelt region of Western Australia, one near Mullewa and the other near Dalwallinu.-Description:...
- B. audaxBanksia audaxBanksia audax is a species of shrub in the plant genus Banksia. It occurs over a large area in the central south of Western Australia.-Description:...
- B. lullfitziiBanksia lullfitziiBanksia lullfitzii is a species of shrub in the plant genus Banksia. A many-branched, spreading bush with golden-orange flowers, it occurs in scattered populations over a large area of the eastern goldfields of Western Australia...
- B. elderianaBanksia elderianaThe Swordfish Banksia , commonly known as the swordfish banksia or palm banksia, is a species of shrub in the plant genus Banksia. It occurs in two disjunct areas in the Goldfields-Esperance region of Western Australia...
- B. laevigataBanksia laevigataBanksia laevigata is a species of shrub in the plant genus Banksia. It occurs in Western Australia's semi-arid shrubland from Southern Cross south to the Fitzgerald River National Park. It is composed of two closely related subspecies, B. laevigata subsp. laevigata and B. laevigata...
- B. laevigata subsp. laevigataBanksia laevigata subsp. laevigataThe Tennis Ball Banksia is a subspecies of small woody shrub in the plant genus Banksia. It occurs in Western Australia's semi-arid shrubland. It and the closely related B. laevigata subsp...
- B. laevigata subsp. fuscoluteaBanksia laevigata subsp. fuscoluteaBanksia laevigata subsp. fuscolutea is a subspecies of Banksia laevigata. It is native to the Southwest Botanical Province of Western Australia....
- B. laevigata subsp. laevigata
- B. elegansBanksia elegansThe Elegant Banksia is a species of shrub or small tree in the plant genus Banksia. It occurs only over a 65 square kilometre area north and west of Eneabba, Western Australia.-Ecology:...
- B. lindleyanaBanksia lindleyanaBanksia lindleyana, commonly known as the Porcupine Banksia, is a species of woody shrub in the genus Banksia of the family Proteaceae. It generally grows as a small shrub to 1 m high with long narrow serrated leaves, and bright yellow oval or round inflorescences...
- B. media
- B. ser. Cyrtostylis
- B. sect. Banksia
- 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 attenuata resolves as a basal member of and next closest relative, or 'sister', to a clade containing B. elegans and, within that, 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. An Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
fossil cone named Banksia archaeocarpa
Banksia archaeocarpa
Banksia archaeocarpa is an extinct species of tree or shrub, known only from a fossil Banksia "cone" recovered from rocks known as the Merlinleigh Sandstone from the Middle Eocene , found in the Kennedy Range in Western Australia. Described in 1983 by Ken McNamara, it closely resembles the extant...
, around 50 million years old, resembles that of B. attenuata.
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 cotyledons; 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. attenuata is placed in B. subg. Banksia.
Distribution and habitat
The most widely distributed of all western banksias, Banksia attenuata occurs across a broad swathe of southwestSouthwest 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
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...
, from Kalbarri National Park
Kalbarri National Park
Kalbarri National Park is located north of Perth. The major geographical features of the park include the Murchison River gorge which runs for nearly 80 kilometres on the lower reaches of the Murchison River...
and the Murchison River
Murchison River (Western Australia)
The Murchison River is the second longest river in Western Australia. It flows for about from the southern edge of the Robinson Ranges to the Indian Ocean at Kalbarri. It has a mean annual flow of about 200 million cubic metres.-Course:...
(with an outlying population in Zuytdorp National Park) southwards right to the southwestern corner of the state at Augusta
Augusta, Western Australia
Augusta is a town on the south-west coast of Western Australia, where the Blackwood River emerges into Flinders Bay. It is the nearest town to Cape Leeuwin, on the farthest south-west corner of the Australian continent. In the 2001 census it had a population of 1,694; by 2006 the population of...
and Cape Leeuwin
Cape Leeuwin
Cape Leeuwin is the most south-westerly mainland point of the Australian Continent, in the state of Western Australia.A few small islands and rocks, the St Alouarn Islands, extend further to the south. The nearest settlement, north of the cape, is Augusta. South-east of Cape Leeuwin, the coast...
, and then eastwards across the south to the western edge of Fitzgerald River National Park
Fitzgerald River National Park
Fitzgerald River National Park is a national park in Western Australia , southeast of Perth, in the Shire of Ravensthorpe and the Shire of Jerramungup....
. Along the eastern border northwards it is found at Lake Grace, Lake Magenta north of Jerramungup
Jerramungup, Western Australia
Jerramungup is a Western Australian town located in the Great Southern agricultural region, southeast of Perth just west of the Gairdner River. The town of Jerramungup was established in 1953 as a war service settlement area...
, and the Wongan Hills
Wongan Hills
Wongan Hills is a range of low flat-topped hills in the Avon Wheatbelt biogeographic region of Western Australia. It is located at , in northern parts of the Avon Wheatbelt biogeographic region....
. It is restricted to various sandy soils, including white, yellow or brown sands, and sand over either 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...
or limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
. It forms an important component of open Eucalyptus
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
woodland as a dominant or understory
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...
tree or tall shrub. To the north, it is a shrubby component of shrubland
Shrubland
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...
. It does not grow on heavy (clay-based) soils, and is hence only found in sandy pockets. Within open woodland, it is found alongside B. menziesii
Banksia menziesii
Banksia menziesii, commonly known as firewood banksia, is a species of flowering plant in the genus Banksia. It is a gnarled tree up to 10 m tall, or a lower spreading 1–3 m shrub in the more northern parts of its range. The serrated leaves are dull green with new growth a paler grey...
, 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...
, B. 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...
, Allocasuarina fraseriana
Allocasuarina fraseriana
Allocasuarina fraseriana, commonly known as western sheoak, common sheoak or just sheoak, is a tree in the family Casuarinaceae. Endemic to Western Australia, it occurs near the coast in the south west corner of the State, from Jurien to Albany .In ideal conditions, Western Sheoak grows to a...
, Eucalyptus marginata, or E. gomphocephala
Eucalyptus gomphocephala
Eucalyptus gomphocephala is a species of tree, also known as Tuart, in the genus Eucalyptus. Native to the southwest of Western Australia the tree grows to over 35m tall. As a durable hardwood the timber is sought after for scantlings, structural timber, the construction of railway carriages, and...
. The annual rainfall within its distribution varies from 300 to 900 mm (12–36 in).
Ecology
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....
, thus promoting recruitment of the next generation; resprouter
Resprouter
Resprouters are plant species that are able to survive fire by the activation of dormant vegetative buds to produce regrowth.Plants may resprout by means of lignotubers at the base or epicormic buds on the trunk or major branches....
s survive fire, resprouting from 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...
or, more rarely, epicormic buds
Epicormic shoot
An epicormic shoot is a shoot growing from an epicormic bud which lies underneath the bark of a trunk, stem, or branch of a plant.-Epicormic buds:...
protected by thick bark. Bearing epicormic buds and a lignotuber, B. attenuata is one of the latter group, with follicles that may open spontaneously or by fire. It is moderately 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...
, storing only one tenth the number of seeds in its seed bank as the reseeding B. hookeriana which it coexists with on sand dunes in scrub at Eneabba
Eneabba, Western Australia
Eneabba is a town on the Brand Highway located 278 km north of Perth, Western Australia.The area is famous for its spectacular display of wildflowers in the spring. It is also home to the Iluka Resources mineral sands facility....
north of Perth. Even then, many of its follicles do not release seed after a fire, but instead after successive autumn rains. An experiment simulating wet weather following a fire saw a series of Banksia attenuata cones with follicles subjected to twice weekly immersions in water after being heated in a ring Bunsen
Bunsen burner
A Bunsen burner, named after Robert Bunsen, is a common piece of laboratory equipment that produces a single open gas flame, which is used for heating, sterilization, and combustion.- Operation:...
flame to around 500–600 °C (930–1100 °F) for two minutes. Cones that had been exposed to water for more weeks had more seed released from follicles over time; around 40% released at three weeks, increasing steadily to almost 90% at ten weeks, compared with a series of controls
Scientific control
Scientific control allows for comparisons of concepts. It is a part of the scientific method. Scientific control is often used in discussion of natural experiments. For instance, during drug testing, scientists will try to control two groups to keep them as identical and normal as possible, then...
(which were kept dry) of which fewer than 10% of seed released. Thus, the seed remains in the follicles until successive rains result in seed dispersal in the wetter winter (instead of dryer summer), increasing the chance of survival. After the follicle is split, the seed and separator are exposed to the elements. The wings of the woody separator are hygroscopic, and move together when wet, and spread and curl apart when dry. The seed is gradually drawn out by the movement with each wetting. Once released, seed germinates at temperatures between 15 and 20 °C (60–70 °F) to optimise timing with autumn and winter rains and hence maximise chance of survival. Still, many seedlings die off in the hot and dry summer months. Seedling survival for the species is lower than for banksias which regenerate by seeding over time. Despite this, the longevity of mature plants allows for maintenance of population until favourable years enable better survival of young plants. As they mature, plants are less likely to perish, and estimated to live for 300 years or more. Analyzing the seed bank and longitudinal results over fifteen years on the Eneabba sandplain showed that B. attenuata would become more abundant over time with fire intervals averaging between 6 and 20 years, peaking with intervals around 10 to 12 years, compared with longer intervals for the reseeders B. hookeriana and B. prionotes. Placed against its rivals, B. attenuata would be dominant between 8 and 10 or 11 years, but at longer intervals is outcompeted by B. hookeriana. Variability in the timing between fires allows all three species to coexist. Exaggerated good and bad weather conditions favours B. attenuata over the reseeding species, which suffer more.
Despite having relatively heavy seed, seed from Banksia attenuata has a high rate of long distance dispersal. A genetic study of populations in Eneabba showed that over 5% of plants had originated up to 2.6 km (1.6 mi) away (similar rates to Banksia hookeriana, the seed of which only weighs half as much). The mechanism for this is unclear, although Byron Lamont has proposed the Short-billed Black Cockatoo (Calyptorhynchus latirostris) as a vector; the species seeks out Banksia attenuata cones after bushfire, possibly because the large seeds and greater chance of grubs in the cone make them more nutritious. Flowering has been recorded one to two years after a bushfire.
Like many members of the family Proteaceae, Banksia attenuata is an obligate 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...
species. Self-incompatible
Self-incompatibility in plants
Self-incompatibility is a general name for several genetic mechanisms in angiosperms, which prevent self-fertilization and thus encourage outcrossing...
, inflorescences require pollinators to be fertilised and produce seed. A genetic study of seed collected near Jandakot published in 1980 showed obligate outcrossing. A field study in the Fitzgerald River National Park where inflorescences were enclosed in mesh fine enough to keep out vertebrates and invertebrates as small as the honey bee (Apis mellifera) showed that follicles still developed, indicating that small invertebrates were able to cross-pollinate the species. Banksia attenuata flowers are visited by the colletid
Colletidae
Colletidae is a family of bees, and are often referred to collectively as plasterer bees or polyester bees, due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secretions dry into a cellophane-like lining...
bee Hylaeus globuliferus and bees of the genus Euhesma
Euhesma
Euhesma is a genus within the bee family Colletidae found in Australia. There are around 46 species with maybe 20 more yet to be described. The group lacks strong unifying features and maybe further split in the future. The type species is Euhesma wahlenbergiae....
. Other pollinating invertebrates recorded include ants and dragonflies. An analysis of the invertebrate population found in the canopy of Banksia woodland found that mites and ticks (acari), beetles (coleoptera) and ants, bees and wasps (hymenoptera
Hymenoptera
Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...
) predominated overall, with the three orders also the most common on B. attenuata along with thrips (thysanoptera). Lower overall numbers of invertebrates on Banksia species were thought to be related to the presence of insectivorous birds.
Many bird species were recorded by the national Banksia Atlas survey, including the New Holland Honeyeater
New Holland Honeyeater
The New Holland Honeyeater is a honeyeater species found throughout southern Australia. It was among the first birds to be scientifically described in Australia, and was initially named Certhia novaehollandiae...
(Phylidonyris novaehollandiae) , Brown Honeyeater
Brown Honeyeater
The Brown Honeyeater is a honeyeater, a group of birds found mainly in Australia and New Guinea which have highly developed brush-tipped tongues adapted for nectar feeding...
(Lichmera indistincta), Singing Honeyeater
Singing Honeyeater
The Singing Honeyeater, Lichenostomus virescens is a small bird found in Australia, and is part of the honeyeater family. Although it is common there, it is not very well known in other places....
(Lichenostomus virescens), Western Spinebill
Western Spinebill
The Western Spinebill, Acanthorhynchus superciliosus, is a honeyeater found in the heath and woodland of south-western Western Australia. It ranges between long, and weighs around . It has a black head, gray back and wings, with a red band behind its neck and from its throat to its breast. There...
(Acanthorhynchus superciliosus), Twenty-eight Parrot
Australian Ringneck
The Australian Ringneck is a parrot native to Australia. Except for extreme tropical and highland areas, the species has adapted to all conditions...
(Barnardius zonarius semitorquatus) and Red-tailed Black Cockatoo
Red-tailed Black Cockatoo
The Red-tailed Black Cockatoo , also known as Banksian- or Banks' Black Cockatoo, is a large cockatoo native to Australia. This species was known as Calyptorhynchus magnificus for many decades until the current scientific name was officially conserved in 1994. It is more common in the drier parts...
(Calyptorhynchus banksii). Black Cockatoos have been observed feeding upon the seed of B. attenuata, although it is not clear which species of black cockatoo was observed, the Short-billed or Long-billed Black Cockatoo (Calyptorhynchus baudinii). At a site near Jandakot, Short-billed Black Cockatoos were observed selecting immature infructescences which bore signs of infestation by the weevil Alphitopis nivea, the larvae of which tunnel in banksia spikes and eat the seed. They extract the larvae and drop the cones.
A 1978 field study conducted around 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....
found the honey possum
Honey Possum
The honey possum or tait, its Native Australian name or noolbenger is a tiny Australian marsupial weighing just seven to eleven grams for the male, and eight to sixteen grams for the female—about half the weight of a mouse. Their physical size ranges from a body length of between 6.5 –...
(Tarsipes rostratus) was a major pollinator of Banksia attenuata, both feeding directly on the pollen and drinking the nectar. The flower structure is suited to passing pollen onto the possum as it feeds, unlike honeyeaters whose bills are too long for this to occur readily. Coupled with the flower spike's musky odour, these findings suggest Banksia attenuata is highly adapted to be pollinated primarily by this mammal species. Furthermore, Petroc Sumner and colleagues have investigated the cone
Cone cell
Cone cells, or cones, are photoreceptor cells in the retina of the eye that are responsible for color vision; they function best in relatively bright light, as opposed to rod cells that work better in dim light. If the retina is exposed to an intense visual stimulus, a negative afterimage will be...
photoreceptor cells of honey possums and compared them with the colour changes of B. attenuata. They found that the possum is trichromatic (like humans and possibly many marsupials) and propose that its L (long wavelength) cones help it discern B. attenuata flower spikes, and the M (or medium wavelength) cones could help it distinguish ripe inflorescences with nectar from recently finished spikes (a difficult task for human vision). There is some evidence for other mammals as pollinators; B. attenuata-like pollen was recovered from museum skins of dunnart
Dunnart
Dunnarts are furry narrow-footed marsupials the size of a mouse, members of the genus Sminthopsis. They are mainly insectivorous. A male dunnart's Y chromosome has only 4 genes, making it the smallest known mammalian Y chromosome....
s (Sminthopsis spp.) and pygmy possums (Cercartetus
Cercartetus
The genus Cercartetus is a group of very small possums known as pygmy possums. Four species comprise this genus, which together with the genus Burramys make up the marsupial family Burramyidae....
spp.), and the sugar glider
Sugar Glider
The sugar glider is a small gliding possum originating from the marsupial family.The sugar glider is native to eastern and northern mainland Australia and is also native to New Guinea and the Bismarck Archipelago.- Habitat :Sugar gliders can be found all throughout the northern and eastern parts of...
(Petaurus breviceps) visited flower spikes in captivity.
Seventeen species from several orders
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of slime molds (myxomycetes) have been isolated from the bark of Banksia attenuata. Over half (nine) were from the order Stemonitales, and Echinosteliales and Liceales
Liceales
Liceida is an order of Amoebozoa....
were also common. The abundance of the first two orders may be due to the acidity of the bark. Another order, the Physarales, was unusually rare—other studies have demonstrated that the order is typically abundant on the bark of various species of tree around the world.
All banksias have developed proteoid or cluster roots in response to the nutrient-poor conditions of Australian soils (particularly lacking in phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
). These have been measured in Eneabba extending to a depth of 15 cm (6 in) below the soil surface. The plant develops masses of fine lateral roots which form a mat-like structure underneath the soil surface, and enable it to extract nutrients as efficiently possible out of the soil. A study of three co-occurring species in Banksia woodland in southwestern Australia—Banksia menziesii, B. attenuata and B. ilicifolia—found that all three develop fresh roots in September after winter rainfall, and that the bacteria populations associated with the root systems of B. menziesii differ from the other two, and that they also change depending on the age of the roots. Another study on root architecture of Banksia hookeriana, B. menziesii and B. attenuata found the overall structure of all three to be similar, with proteoid mats more active and growing in wetter months (winter-spring). Plants send out several sinker roots which descend to reach the water table
Water table
The water table is the level at which the submarine pressure is far from atmospheric pressure. It may be conveniently visualized as the 'surface' of the subsurface materials that are saturated with groundwater in a given vicinity. However, saturated conditions may extend above the water table as...
, and the original tap root may or may not have died off. Along with B. amenziesii, B. attenuata is a facultative phreatophyte. The two species are less strictly tied to the water table
Water table
The water table is the level at which the submarine pressure is far from atmospheric pressure. It may be conveniently visualized as the 'surface' of the subsurface materials that are saturated with groundwater in a given vicinity. However, saturated conditions may extend above the water table as...
and hence able to grow in a wider variety of places within Banksia woodland habitat around Perth than the co-occurring 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...
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...
. A study at a rehabilitation site on a sand mine north of Perth found that the broadleaved species B. attenuata and B. hookeriana were harder to establish than the fine-leaved B. leptophylla
Banksia leptophylla
The Slender-leaved Banksia is a species of shrub in the plant genus Banksia. It occurs along the west coast of Western Australia from Gingin to Kalbarri. Before Alex George's revision of 1981, it was labelled informally as B. sphaerocarpa var. pinifolia or var...
there, due to increased impedance of the disturbed soil. Analysis of native plant species at a remnant of banksia woodland in suburban Perth which had been invaded by two herbaceous weed species (Ehrharta calycina
Ehrharta calycina
Ehrharta calycina is a species of grass known by the common names perennial veldtgrass and purple veldtgrass. It is native to southern Africa, but it is known elsewhere as an introduced species, often becoming weedy...
and Pelargonium capitatum
Pelargonium capitatum
Pelargonium capitatum is one of several species known as rose-scented pelargonium in English. The popular names refer to the scent of the essential oils extracted from glandular tissue, not the flowers, which have hardly any scent to speak of. Some of the species are known as kusmalva in...
) found increased phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
levels in native foliage. Although B. attenuata leaves did not have increased phosphorus, they did have reduced levels of manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
—an element which is absorbed into the plant by its proteoid roots, the formation of which can be inhibited by raised levels of phosphorus.
In a 1985 study inoculating cultivated plants, Banksia attenuata showed moderate to high susceptibility to Phytophthora cinnamomi
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...
dieback; and at least some field and cultivation evidence points to it being highly susceptible. P. cinnamomi spreads from plant to plant via lateral roots, advancing at a rate of around a metre a year. The symptoms of infection in Banksia attenuata include yellowing of the leaves in the tree crown, and lesions at the base of the trunk. The red healthy roots become discoloured brown. A study of Banksia attenuata woodland 400 km (250 mi) southeast of Perth across 16 years and following a wave of P. cinnamomi infestation showed that B. attenuata populations still existed but were significantly reduced in diseased areas. Injecting a solution of 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...
into the trunks of affected B. attenuata trees at a disease front in Banksia woodland can delay morbidity from dieback for five years. Injecting and spraying phosphite also reduces the rate of spread of a dieback front for around five years. A bushfire did not influence this slowing. A 2003 study found that drenching the soil with 0.50 mM benzoic acid
Benzoic acid
Benzoic acid , C7H6O2 , is a colorless crystalline solid and the simplest aromatic carboxylic acid. The name derived from gum benzoin, which was for a long time the only source for benzoic acid. Its salts are used as a food preservative and benzoic acid is an important precursor for the synthesis...
significantly reduced the size of P. cinnamomi lesions. Research into dieback in Western Australia has identified a new species, P. multivora, isolated from ailing eucalypts and B. attenuata in 2009.
Cultivation and cultural use
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...
between 5.5 and 7.0. They are sensitive to 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...
, and do not fare well in humid climates. Seeds do not require any treatment, and take 16 to 49 days to germinate. Seedlings are highly vulnerable to damping off
Damping off
Damping off is the term used for a number of different fungus-caused ailments that can kill seeds or seedlings before or after they germinate....
. Plants take from four to six years to flower from seed. There has been little success with other methods of improving adaptability to humid climates such as grafting
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...
.
Flower spikes in late bud are used in the cut flower industry, primarily in Western Australia.
Aboriginal
Indigenous Australians
Indigenous Australians are the original inhabitants of the Australian continent and nearby islands. The Aboriginal Indigenous Australians migrated from the Indian continent around 75,000 to 100,000 years ago....
people placed the flower spike in a paperbark-lined hole filled with water to make a sweet drink
Australian Aboriginal sweet foods
Australian Aborigines had many ways to source sweet foods. The four main types of sweet foods gathered – apart from ripe fruit – were:* honey from ants and bees * leaf scale * tree sap* flower nectar...
. Both this species and B. aemula
Banksia aemula
Banksia aemula, commonly known as the wallum banksia, is a lignotuberous shrub of the Proteaceae family. Found from Bundaberg south to Sydney on the Australian east coast, it is encountered as a shrub or a taller tree to 8 m in coastal heath on deep sandy soil, known as Wallum...
have been credited with the inspiration behind May Gibbs
May Gibbs
Cecilia May Gibbs MBE was an Australian children's author, illustrator, and cartoonist. She is best-known for her gumnut babies , and the book Snugglepot and Cuddlepie....
' Big Bad Banksia Men
Snugglepot and Cuddlepie
Snugglepot and Cuddlepie is a series of books written by Australian author May Gibbs. The books chronicle the adventures of the eponymous Snugglepot and Cuddlepie. The central story arc concerns Snugglepot and Cuddlepie and their adventures along with troubles with the villains of the story, the ...
; this species was familiar to Gibbs in her childhood and likely gave her the initial inspiration, although the depictions resemble the latter species. Artist Marianne North
Marianne North
Marianne North was an English naturalist and botanical artist-Life with her parents:Marianne North was born at Hastings, the eldest daughter of a prosperous land-owning family descended from the Hon. Roger North, younger son of Dudley North, 4th Baron North...
produced a highly regarded painting of B. attenuata during her stay in Australia in 1880–81.