Fern-leaved banksia | |
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Banksia oblongifolia, Georges River National Park | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Proteales |
Family: | Proteaceae |
Genus: | Banksia |
Subgenus: | Banksia subg. Banksia |
Section: | Banksia sect. Banksia |
Series: | Banksia ser. Salicinae |
Species: | B. oblongifolia |
Binomial name | |
Banksia oblongifolia | |
Distribution of B. oblongifolia (green) | |
Synonyms [2] | |
Banksia oblongifolia, commonly known as the fern-leaved, dwarf or rusty banksia, is a species in the plant genus Banksia . Found along the eastern coast of Australia from Wollongong, New South Wales in the south to Rockhampton, Queensland in the north, it generally grows in sandy soils in heath, open forest or swamp margins and wet areas. A many-stemmed shrub up to 3 m (9.8 ft) high, it has leathery serrated leaves and rusty-coloured new growth. The yellow flower spikes, known as inflorescences, most commonly appear in autumn and early winter. Up to 80 follicles, or seed pods, develop on the spikes after flowering. Banksia oblongifolia resprouts from its woody lignotuber after bushfires, and the seed pods open and release seed when burnt, the seed germinating and growing on burnt ground. Some plants grow between fires from seed shed spontaneously.
Spanish botanist Antonio José Cavanilles described B. oblongifolia in 1800, though it was known as Banksia aspleniifolia in New South Wales for many years. However, the latter name, originally coined by Richard Anthony Salisbury, proved invalid, and Banksia oblongifolia has been universally adopted as the correct scientific name since 1981. Two varieties were recognised in 1987, but these have not been generally accepted. A wide array of mammals, birds, and invertebrates visit the inflorescences. Though easily grown as a garden plant, it is not commonly seen in horticulture.
Banksia oblongifolia is a shrub that can reach 3 m (9.8 ft) high, [3] though is generally less than 2 m (6.6 ft) high, [4] with several stems growing out of a woody base known as a lignotuber. The smooth bark is marked with horizontal lenticels, and is reddish-brown fading to greyish-brown with age. New leaves and branchlets are covered with a rusty fur. The leaves lose their fur and become smooth with maturity, and are alternately arranged along the stem. Measuring 5–11 cm (2.0–4.3 in) in length and 1.5–2 cm (0.59–0.79 in) in width, the leathery green leaves are oblong to obovate (egg-shaped) or truncate with a recessed midvein and mildly recurved margins, which are entire at the base and serrate towards the ends of the leaves. The sinuses (spaces between the teeth) are U-shaped and teeth are 1–2 mm long. The leaf underside is whitish with a reticulated vein pattern and a raised central midrib. [5] The leaves sit on 2–5 mm long petioles. [3]
Flowering has been recorded between January and October, with a peak in autumn and early winter (April to June). [6] The inflorescences, or flower spikes, arise from the end of 1 to 5 year old branchlets, and often have a whorl of branchlets arising from the node or base. Measuring 5–15 cm (2.0–5.9 in) high and 4 cm (1.6 in) wide, the yellow spikes often have blue-grey tinged limbs in bud, [3] though occasionally pinkish, mauve or mauve-blue limbs are seen. [7] Opening to a pale yellow after anthesis, the spikes lose their flowers with age and swell to up to 17.5 cm (6.9 in) high and 4 cm (1.6 in) wide, with up to 80 follicles. Covered with fine fur but becoming smooth with age, the oval-shaped follicles measure 1–1.8 cm (0.39–0.71 in) long by 0.2–0.7 cm high (0.1–0.3 in) and 0.3–0.7 cm (0.12–0.28 in) wide. [3] The bare swollen spike, now known as an infructescence, is patterned with short spiky persistent bracts on its surface where follicles have not developed. [5] Each follicle contains one or two obovate dark grey-brown to black seeds sandwiching a woody separator. Measuring 1.2–1.8 cm (0.47–0.71 in) long, they are made up of an oblong to semi-elliptic smooth or slightly ridged seed body, 0.7–1.1 cm (0.28–0.43 in) long by 0.3–0.7 cm (0.12–0.28 in) wide. The woody separator is the same shape as the seed, with an impression where the seed body lies next to it. [3] Seedlings have bright obovate green cotyledons 1.2–1.5 cm (0.47–0.59 in) long and 0.5–0.7 cm (0.20–0.28 in) wide, which sit on a stalk, or 1 mm diameter finely hairy seedling stem, known as the hypocotyl, which is less than 1 cm high. The first seedling leaves to emerge are paired (oppositely arranged) and lanceolate with fine-toothed margins, measuring 2.5–3 cm long and 0.4–0.5 cm wide. Subsequent leaves are more oblanceolate, elliptic (oval-shaped) or linear. Young plants develop a lignotuber in their first year. [3]
Banksia oblongifolia can be distinguished from B. robur , which it often co-occurs with, by its smaller leaves and bare fruiting spikes. B. robur has more metallic green flower spikes, and often grows in wetter areas within the same region. B. plagiocarpa has longer leaves with more coarsely serrated margins, and its flower spikes are blue-grey in bud, and later bear wedge-shaped follicles. [3] In the Sydney Basin, B. paludosa also bears a superficial resemblance to B. oblongifolia, but its leaves are more prominently spathulate (spoon-shaped) and tend to point up rather than down. The leaf undersides are white and lack the prominent midrib of B. oblongifolia, the new growth is bare and lacks the rusty fur, and the aged flower parts remain on the old spikes. [8]
First collected by Luis Née between March and April 1793, the fern-leaved banksia was described by Antonio José Cavanilles in 1800 as two separate species from two collections, first as Banksia oblongifolia from the vicinity of Port Jackson (Sydney), [9] and then as Banksia salicifolia from around Botany Bay. [10] Derived from the Latin words oblongus "oblong", and folium "leaf", the species name refers to the shape of the leaves. [11] Richard Anthony Salisbury had published the name Banksia aspleniifolia in 1796 based on leaves of cultivated material. [3]
Robert Brown recorded 31 species of Banksia in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen , and used the epithet oblongifolia in his taxonomic arrangement, placing the taxon in the subgenus Banksia verae , the "True Banksias", because the inflorescence is a typical Banksia flower spike. He recognised B. salicifolia as the same species at this point, [12] but was unsure whether Salisbury's B. aspleniifolia belonged under the same name. [3] By the time Carl Meissner published his 1856 arrangement of the genus, there were 58 described Banksia species. Meissner divided Brown's Banksia verae, which had been renamed Eubanksia by Stephan Endlicher in 1847, [13] into four series based on leaf properties. He followed Brown in using the name B. oblongifolia, and placed it in the series Salicinae. [14]
In 1870, George Bentham published a thorough revision of Banksia in his landmark publication Flora Australiensis . In Bentham's arrangement, the number of recognised Banksia species was reduced from 60 to 46. He declared B. oblongifolia referrable to, and a synonym of, B. integrifolia . Bentham defined four sections based on leaf, style and pollen-presenter characters. B. integrifolia was placed in section Eubanksia. [15]
Botanists in the 20th century recognised B. oblongifolia as a species in its own right, but disagreed on the name. Those in Queensland felt Salisbury's name was invalid and used Banksia oblongifolia, while New South Wales authorities used Banksia aspleniifolia as it was the oldest published name for the species. Botanist and banksia authority Alex George ruled that oblongifolia was the correct name in his 1981 revision of the genus. After reviewing Salisbury's original species description, which is of the leaves alone, he concluded that it does not diagnose the species to the exclusion of others and is hence not a validly published name—the description could have applied to juvenile leaves of B. paludosa , B. integrifolia or even B. marginata . [3]
The current taxonomic arrangement of the genus Banksia is based on botanist Alex George's 1999 monograph for the Flora of Australia book series. [2] In this arrangement, B. oblongifolia is placed in Banksia subgenus Banksia , because its inflorescences take the form of Banksia's characteristic flower spikes, section Banksia because of its straight styles, and series Salicinae because its inflorescences are cylindrical. In a morphological cladistic analysis published in 1994, Kevin Thiele placed it in the newly described subseries Acclives along with B. plagiocarpa , B. robur and B. dentata within the series Salicinae. [16] However, this subgrouping of the Salicinae was not supported by George. [2] B. oblongifolia's placement within Banksia 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 oblongifolia resolves as the closest relative, or "sister", to B. robur, with B. plagiocarpa as next closest relative. [17] [18] [19] 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, B. oblongifolia is placed in B. subg. Spathulatae. [20]
George noted that Banksia oblongifolia showed considerable variation in habit, and in 1987 Conran and Clifford separated the taxon into two subspecies. In examining populations in southern Queensland, they reported that the two forms were distinct in growth habit and habitat, and that they did not find any intermediate forms. [21] New South Wales botanists Joseph Maiden and Julius Henry Camfield had collected this taller form of B. oblongifolia in Kogarah in 1898, and given it the name Banksia latifolia variety minor—B. latifolia being a published name by which B. robur was known—before Maiden and Ernst Betche renamed it Banksia robur variety minor. [3] This name (confusingly) thus became the name for the taller variety. They defined variety oblongifolia as a multistemmed shrub 0.5–1.3 m (20–51 in) high, with leaves 3–11 cm (1.2–4.3 in) long and 1–2.5 cm (0.39–0.98 in) wide, and flower spikes 4–10 cm (1.6–3.9 in) high. The habitat is swamps and swamp borders, or rarely sandstone ridges. Variety minor is a taller shrub 1–3.5 m (3.3–11.5 ft) high with leaves up to 16 cm (6.3 in) long and spikes 6 to 14 cm (2.4 to 5.5 in) high. It is an understory plant in sclerophyll forests, associated with Eucalyptus signata and Banksia spinulosa var. collina. Both subspecies occur throughout the range. [21] However, George rejected the varieties, stating the variability was continuous. [2]
Banksia robur and B. oblongifolia hybrids have been recorded at several locations along the eastern coastline. Field workers for The Banksia Atlas recorded 20 populations between Wollongong and Pialba in central Queensland. [4] Locales include Calga north of Sydney, Ku-ring-gai Chase National Park, and Cordeaux Dam near Wollongong. [3] A study of an area of extensive hybridization between the two near Darkes Forest on the Woronora Plateau south of Sydney revealed extensive hybridization in mixed species stands but almost none in pure stands of either species there. Genetic analysis showed generations of crossing and complex ancestry. Morphology generally correlated with genetic profile, but occasionally plants that resembled one parent had some degree of genetic hybridization. Furthermore, there were a few plants with morphology suggestive of a third species, B. paludosa, in their parentage, and requiring further investigation. [22] A possible hybrid between B. oblongifolia and B. integrifolia was recorded near Caloundra by Banksia Atlas volunteers. [4]
Banksia oblongifolia occurs along the eastern coast of Australia from Wollongong, New South Wales, in the south to Rockhampton, Queensland, in the north. [4] There are isolated populations offshore on Fraser Island, [3] and inland at Blackdown Tableland National Park and Crows Nest in Queensland, and also inland incursions at the base of the Glasshouse Mountains in southern Queensland, at Grafton in northern New South Wales, and Bilpin and Lawson in the Blue Mountains west of Sydney. [4] B. oblongifolia grows in a range of habitats—in damp areas with poor drainage, along the edges of swamps and flats, as well as wallum shrubland, [3] or coastal plateaux. [6] It is also found in open forest or woodland, where it grows on ridges or slopes, [3] [4] or heath. Soils are predominantly sandy or sandstone-based, though granite-based and clay-loams are sometimes present. [3] [6]
Associated species in the Sydney region include heathland species such as heath banksia ( Banksia ericifolia ), coral heath ( Epacris microphylla ) and mountain devil ( Lambertia formosa ), and tick bush ( Kunzea ambigua ) and prickly-leaved paperbark ( Melaleuca nodosa ) in taller scrub, and under trees such as scribbly gum ( Eucalyptus sclerophylla ) and narrow-leaved apple ( Angophora bakeri ) in woodland. [6] The Agnes Banks Woodland in western Sydney has been recognised by the New South Wales Government as an Endangered Ecological Community. Here B. oblongifolia is an understory plant in low open woodland, with scribbly gum, narrow-leaved apple and old man banksia ( B. serrata ) as canopy trees, and wallum banksia ( B. aemula ), variable smoke-bush ( Conospermum taxifolium ), wedding bush ( Ricinocarpos pinifolius ), showy parrot-pea ( Dillwynia sericea ) and nodding geebung ( Persoonia nutans ) as other understory species. [23]
Banksia oblongifolia plants can live for more than 60 years. [6] They respond to bushfire by resprouting from buds located on the large woody lignotuber. Larger lignotubers have the greatest number of buds, although buds are more densely spaced on smaller lignotubers. A 1988 field study in Ku-ring-gai Chase National Park found that shoots grow longer after fire, particularly one within the previous four years, and that new buds grow within six months after a fire. [24] These shoots are able to grow, flower and set seed two to three years after a fire. [25] The woody infructescences also release seeds as their follicles are opened with heat, [6] although a proportion do open spontaneously at other times. One field study in Ku-ring-gai Chase National Park found 10% opened in the absence of bushfire, and that seeds germinated, and young plants do grow. [26] Older plants are serotinous, that is, they store large numbers of seed in an aerial seed bank in their canopy that are released after fire. [25] Being relatively heavy, the seeds do not disperse far from the parent plant. [6]
Bird species that have been observed foraging and feeding at the flowers include the red wattlebird (Anthochaera carunculata), Lewin's honeyeater (Meliphaga lewinii), brown honeyeater (Lichmera indistincta), tawny-crowned honeyeater (Gliciphila melanops), yellow-faced honeyeater (Lichenostomus chrysops), white-plumed honeyeater (L. penicillatus), white-cheeked honeyeater (Phylidonyris niger), New Holland honeyeater (P. novaehollandiae), noisy friarbird (Philemon corniculatus), noisy miner (Manorina melanocephala) and eastern spinebill (Acanthorhynchus tenuirostris). [4] Insects recorded visiting flower spikes include the European honey bee and ants. [4] The swamp wallaby ( Wallabia bicolor ) eats new shoots that grow from lignotubers after bushfire. [24]
One field study found 30% of seeds were eaten by insects between bushfires. [24] Insects recovered from inflorescences include the banksia boring moth ( Arotrophora arcuatalis ), younger instars of which eat flower and bract parts before tunneling into the woody axis of the spike as they get older and boring into follicles and eating seeds. Other seed predators include unidentified species of moth of the genera Cryptophasa and Xylorycta , as well as Scieropepla rimata , Chalarotona intabescens and Chalarotona melipnoa and an unidentified weevil species. [27] The fungal species Asterina systema-solare , Episphaerella banksiae and Lincostromea banksiae have been recorded on the leaves. [6]
Like most other proteaceae, B. oblongifolia has proteoid roots—roots with dense clusters of short lateral rootlets that form a mat in the soil just below the leaf litter. These enhance solubilisation of nutrients, allowing nutrient uptake in low-nutrient soils such as the phosphorus-deficient native soils of Australia. [28] A study of coastal heaths on Pleistocene sand dunes around the Myall Lakes found B. oblongifolia on slopes (wet heath) and B. aemula grew on ridges (dry heath), and the two species did not overlap. [29] Manipulation of seedlings in the same study area showed that B. oblongifolia can grow longer roots seeking water than other wet heath species and that seedlings can establish in dry heath, but it is as yet unclear why the species does not grow in dry heath as well as wet heath. [30] Unlike similar situations with Banksia species in Western Australia, the two species did not appear to impact negatively on each other. [31]
Conrad Loddiges and his sons wrote of Banksia oblongifolia in volume 3 of their work The Botanical Cabinet in 1818, reporting it had been brought into cultivation in 1792, though had been initially and incorrectly called Banksia dentata. It flowered in November in the United Kingdom, and was grown in a greenhouse over winter. [32]
Not commonly cultivated, [33] it adapts readily to garden conditions and tolerates most soils in part-shade or full sun. [11] The colours of the inflorescences in bud, [7] and timing of flowers into winter give it horticultural value, as does its reddish new growth. [11] Larger plants have taller flower spikes. [7] It is propagated readily from seed, [11] with young plants taking five to seven years to flower from seed. [7] Pruning can improve the shrub's appearance, [11] and it is a potential bonsai subject. [7]
Banksia serrata, commonly known as the saw banksia, the old man banksia, the saw-tooth banksia or the red honeysuckle and as wiriyagan by the Cadigal people, is a species of woody shrub or tree of the genus Banksia, in the family Proteaceae. Native to the east coast of Australia, it is found from Queensland to Victoria with outlying populations on Tasmania and Flinders Island. Commonly growing as a gnarled tree up to 16 m (50 ft) in height, it can be much smaller in more exposed areas. This Banksia species has wrinkled grey bark, shiny dark green serrated leaves and large yellow or greyish-yellow flower spikes appearing over summer. The flower spikes, or inflorescences, turn grey as they age and pollinated flowers develop into large, grey, woody seed pods called follicles.
Banksia ericifolia, the heath-leaved banksia, or lantern banksia, is a species of woody shrub of the family Proteaceae native to Australia. It grows in two separate regions of Central and Northern New South Wales east of the Great Dividing Range. Well known for its orange or red autumn inflorescences, which contrast with its green fine-leaved heath-like foliage, it is a medium to large shrub that can reach 6 m (20 ft) high and wide, though is usually half that size. In exposed heathlands and coastal areas, it is more often 1–2 m (3.3–6.6 ft).
Banksia robur, commonly known as swamp banksia, or less commonly broad-leaved banksia, grows in sand or peaty sand in coastal areas from Cooktown in north Queensland to the Illawarra region on the New South Wales south coast. It is often found in areas which are seasonally inundated.
Banksia spinulosa, the hairpin banksia, is a species of woody shrub, of the genus Banksia in the family Proteaceae, native to eastern Australia. Widely distributed, it is found as an understorey plant in open dry forest or heathland from Victoria to northern Queensland, generally on sandstone though sometimes also clay soils. It generally grows as a small shrub to 2 metres (7 ft) in height, though can be a straggly tree to 6 metres (20 ft). It has long narrow leaves with inflorescences which can vary considerably in coloration; while the spikes are gold or less commonly yellowish, the emergent styles may be a wide range of colours – from black, purple, red, orange or yellow.
Banksia aemula, commonly known as the wallum banksia, is a shrub of the family Proteaceae. Found from Bundaberg south to Sydney on the Australian east coast, it is encountered as a shrub or a tree to 8 m (26 ft) in coastal heath on deep sandy soil, known as Wallum. It has wrinkled orange bark and shiny green serrated leaves, with green-yellow flower spikes, known as inflorescences, appearing in autumn. The flower spikes turn grey as they age and large grey follicles appear. Banksia aemula resprouts from its woody base, known as a lignotuber, after bushfires.
Banksia attenuata, commonly known as the candlestick banksia, slender banksia, or biara to the Noongar people, is a species of plant in the family Proteaceae. Commonly a tree, it reaches 10 m (33 ft) high, but it is often a shrub in drier areas 0.4 to 2 m high. It has long, narrow, serrated leaves and bright yellow inflorescences, 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. The candlestick banksia 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.
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 (33 ft) tall, or a lower spreading 1–3 m (3.3–9.8 ft) shrub in the more northern parts of its range. The serrated leaves are dull green with new growth a paler grey green. The prominent autumn and winter inflorescences are often two-coloured red or pink and yellow, and their colour has given rise to more unusual common names such as port wine banksia and strawberry banksia. Yellow blooms are rarely seen.
Banksia aculeata, commonly known as prickly banksia, is a species of plant of the family Proteaceae native to the Stirling Range in the southwest of Western Australia. A shrub up to 2 m (7 ft) tall, it has dense foliage and leaves with very prickly serrated margins. Its unusual pinkish, pendent (hanging) flower spikes, known as inflorescences, are generally hidden in the foliage and appear during the early summer. Although it was collected by the naturalist James Drummond in the 1840s, Banksia aculeata was not formally described until 1981, by Alex George in his monograph of the genus.
Banksia burdettii, commonly known as Burdett's banksia, is a species of shrub or tree of the genus Banksia in the family Proteaceae. It occurs on sandplain country north of Gingin, Western Australia. Growing to 4 m (13 ft) in height, it has long serrated leaves and large, bright flower spikes, initially white before opening to a bright orange, that appear mainly in late summer. Edmund Gilbert Baker described B. burdettii in 1934, naming it after its collector, W. Burdett.
Banksia canei, commonly known as the mountain banksia, is a species of shrub that is endemic to southeastern Australia. It is generally encountered as a many-branched shrub that grows up to 3 m (10 ft) high, with narrow leaves and the yellow inflorescences appearing from late summer to early winter. The old flowers fall off the spikes and up to 150 finely furred follicles develop, which remain closed until burnt in a bushfire. Each follicle bears two winged seeds. Response to fire is poorly known, although it is thought to regenerate by seed. Birds such as the yellow-tufted honeyeater and various insects forage among the flower spikes. It is frost tolerant in cultivation, but copes less well with aridity or humidity and is often short-lived in gardens. One cultivar, Banksia 'Celia Rosser', was registered in 1978, but has subsequently vanished.
Banksia dentata, commonly known as the tropical banksia, is a species of tree in the genus Banksia. It occurs across northern Australia, southern New Guinea and the Aru Islands. Growing as a gnarled tree to 7 m (23 ft) high, it has large green leaves up to 22 cm (8.7 in) long with dentate (toothed) margins. The cylindrical yellow inflorescences, up to 13 cm (5.1 in) high, appear over the cooler months, attracting various species of honeyeaters, sunbirds, the sugar glider and a variety of insects. Flowers fall off the ageing spikes, which swell and develop follicles containing up to two viable seeds each.
Banksia grossa is a species of shrub in the family Proteaceae and is endemic to Southwest Australia. It is one of fourteen species of banksia of the series Abietinae, all of which bear predominantly cylindrical or oval inflorescences. Collected in 1965, it was first formally described in 1981 by Alex George. Its thick leaves and large seeds distinguish it from other members of the Abietinae, and are the basis of its species name.
Banksia lemanniana, the yellow lantern banksia or Lemann's banksia, is a species of flowering plant in the family Proteaceae, native to Western Australia. It generally grows as an open woody shrub or small tree to 5 m (16 ft) high, with stiff serrated leaves and unusual hanging inflorescences. Flowering occurs over summer, the greenish buds developing into oval flower spikes before turning grey and developing the characteristic large woody follicles. It occurs within and just east of the Fitzgerald River National Park on the southern coast of the state. B. lemanniana is killed by bushfire and regenerates from seed.
Banksia marginata, commonly known as the silver banksia, is a species of tree or woody shrub in the plant genus Banksia found throughout much of southeastern Australia. It ranges from the Eyre Peninsula in South Australia to north of Armidale, New South Wales, and across Tasmania and the islands of Bass Strait. It grows in various habitats, including Eucalyptus forest, scrub, heathland and moorland. Banksia marginata varies widely in habit, ranging from a 20-centimetre (7.9 in) shrub to a 12-metre (40 ft) tree. The narrow leaves are linear and the yellow inflorescences occur from late summer to early winter. The flower spikes fade to brown and then grey and develop woody follicles bearing the winged seeds. Originally described by Antonio José Cavanilles in 1800, further collections of B. marginata were designated as several separate species by Robert Brown in 1810. However, all were reclassified as a single species by George Bentham in 1870. No distinct subspecies have been recognised by Banksia expert Alex George, who nonetheless concedes that further work is needed.
Banksia paludosa, commonly known as the marsh or swamp banksia, is a species of shrub in the plant genus Banksia. It is native to New South Wales, Australia, where it is found between Sydney and Batemans Bay, with an isolated population further south around Eden. There are two recognised subspecies, the nominate of which is a spreading shrub to 1.5 m (4.9 ft) in height, and subsp. astrolux is a taller shrub to 5 m (16 ft) high found only in Nattai National Park.
Banksia plagiocarpa, commonly known as the Dallachy's banksia or blue banksia, is a species of shrub or tree in the plant genus Banksia. It occurs only on Hinchinbrook Island, Queensland and the immediately adjacent mainland. First collected in 1867, Banksia plagiocarpa was not described until 1981, when Alex George named it in his monograph of the genus Banksia. Genetic studies show it to be related to Banksia aquilonia, Banksia oblongifolia and Banksia robur.
Banksia saxicola, the rock banksia or Grampians banksia, is a species of tree or shrub in the plant genus Banksia. It occurs in Victoria in two distinct populations, one in The Grampians and the other on Wilsons Promontory. Formerly considered to be a form of B. integrifolia, it was described as a distinct species by Alex George in 1981. It is most closely related to Banksia marginata.
Banksia speciosa, commonly known as the showy banksia, is a species of large shrub or small tree in the family Proteaceae. It is found on the south coast of Western Australia between Hopetoun (33°57′ S) and the Great Australian Bight, growing on white or grey sand in shrubland. Reaching up to 8 m (26 ft) in height, it is a single-stemmed plant that has thin leaves with prominent triangular "teeth" along each margin, which are 20–45 cm (7.9–17.7 in) long and 2–4 cm (0.8–1.6 in) wide. The prominent cream-yellow flower spikes known as inflorescences appear throughout the year. As they age they develop up to 20 follicles each that store seeds until opened by fire. Though widely occurring, the species is highly sensitive to dieback and large populations of plants have succumbed to the disease.
Banksia violacea, commonly known as violet banksia, is a species of shrub or tree in the plant genus Banksia. It generally grows as a small shrub to 1.5 m (5 ft) high with fine narrow leaves, and is best known for its unusually coloured dark purple-violet inflorescences. The colour of the inflorescences, short leaves, and flattened follicles which are sticky when young, help identify this species from others in the field. It is found in low shrubland in southern regions of Western Australia from Esperance in the east to Narrogin in the west, growing exclusively in sandy soils.
Banksia aquilonia, commonly known as the northern banksia and jingana, is a tree in the family Proteaceae and is endemic to north Queensland on Australia's northeastern coastline. With an average height of 8 m (26 ft), it has narrow glossy green leaves up to 20 cm (7.9 in) long and 6 to 10 cm high pale yellow flower spikes, known as inflorescences, appearing in autumn. As the spikes age, their flowers fall off and they develop up to 50 follicles, each of which contains two seeds.