Banksia plagiocarpa
Encyclopedia
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.
s, are 7 to 14 cm (2.8–5.6 in) high and 5-6 cm (2-2.4 in) in diameter at anthesis
. Arising terminally or from one to two year old branches, they are often surrounded at the base by a whorl of small branchlets.
) from Bishops Peak in the Cardwell Ranges, the specimens lodged at Kew
and Melbourne Herbariums
. However, it was not collected again until 28 December 1979 by Fred Hockings from Hinchinbook Island. Both Dallachy and Hockings remarked on the unusual flower colour, the former describing it as "pale blue", the latter "greenish-purple". It was finally described in Alex George's 1981 revision of the genus. The species name is derived from the Ancient Greek
words plagios "sloping" or "oblique", and carpos "fruit", and refers to the upturned wedge-shaped follicles. Common names include Dallachy's banksia and blue banksia.
The current taxonomic
arrangement of the Banksia genus is based on botanist Alex George
's 1999 monograph for the Flora of Australia
book series. In this arrangement, B. plagiocarpa 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. George held it to be most closely related to Banksia oblongifolia
, which he noted often had flower spikes that were tinged blue-grey in bud, and also have affinities to the co-occurring species Banksia aquilonia
In a morphological
cladistic analysis published in 1994, Kevin Thiele
placed it in the newly described subseries Acclives, within the series Salicinae. It appeared to be the earliest offshoot of the group, which also consisted of B. oblongifolia, B. dentata
and B. robur
. However, this subgrouping of the Salicinae was not supported by George.
B. plagiocarpa' s placement within Banksia may be summarised as follows:
, where it is found on the top and slopes of Mount Bowen
and Nina Peak, and the adjacent mainland on the Queensland north coast, where it is found on the summit and slopes of Bishops Peak. The annual rainfall is 2400 mm (95 in). The habitat is either open woodland or grassland, and it can be the dominant shrub. The altitude it grows at on Hinchinbrook is between 200 and 720 m (650–2200 ft), on gravelly, rocky or clay soils, and in association with such plants as Leptospermum polygalifolium
and she-oaks (Casuarina
), as well as Banksia aquilonia
at lower altitudes below 400 m (1200 ft). On the mainland, it is found in a more sandy soil, often near water.
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...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
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...
. It occurs only on Hinchinbrook Island
Hinchinbrook Island
Hinchinbrook Island lies east of Cardwell and north of Lucinda, Queensland Australia. Hinchinbrook Island is part of the Great Barrier Reef Marine Park and wholly protected within the Hinchinbrook Island National Park, except for a small resort. It is the largest island on the Great Barrier Reef...
, Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
and the immediately adjacent mainland.
Description
Banksia plagiocarpa grows as a shrub to 5 m (16 ft) high with greyish broken bark. The new growth is covered in red velvety fur, which falls off after two or three years. The long narrow lanceolate (spear-shaped) to obovate leaves are arranged alternately along the stems. Measuring 8 to 20 cm (3–8 in) long by 0.6–1.7 cm (0.2–0.6 in) wide, they have recurved margins lined with blunt serrations. Appearing from February to July, the flower spikes, known as inflorescenceInflorescence
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, are 7 to 14 cm (2.8–5.6 in) high and 5-6 cm (2-2.4 in) in diameter at anthesis
Anthesis
Anthesis is the period during which a flower is fully open and functional. It may also refer to the onset of that period.The onset of anthesis is spectacular in some species. In Banksia species, for example, anthesis involves the extension of the style far beyond the upper perianth parts...
. Arising terminally or from one to two year old branches, they are often surrounded at the base by a whorl of small branchlets.
Taxonomy
Banksia plagiocarpa was first collected on 20 December 1867 and 21 February 1868 by John Dallachy (a collector for Victorian Government Botanist Ferdinand von MuellerFerdinand von Mueller
Baron Sir Ferdinand Jacob Heinrich von Mueller, KCMG was a German-Australian physician, geographer, and most notably, a botanist.-Early life:...
) from Bishops Peak in the Cardwell Ranges, the specimens lodged at Kew
Royal Botanic Gardens, Kew
The Royal Botanic Gardens, Kew, usually referred to as Kew Gardens, is 121 hectares of gardens and botanical glasshouses between Richmond and Kew in southwest London, England. "The Royal Botanic Gardens, Kew" and the brand name "Kew" are also used as umbrella terms for the institution that runs...
and Melbourne Herbariums
National Herbarium of Victoria
The National Herbarium of Victoria is one of Australia’s premier state herbaria. It was established in 1853 and is sited within the Royal Botanic Gardens, Melbourne. The present building was constructed in 1934 through a donation from philanthropist Sir Macpherson Robertson. It, along with a...
. However, it was not collected again until 28 December 1979 by Fred Hockings from Hinchinbook Island. Both Dallachy and Hockings remarked on the unusual flower colour, the former describing it as "pale blue", the latter "greenish-purple". It was finally described in Alex George's 1981 revision of the genus. The species name is derived from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
words plagios "sloping" or "oblique", and carpos "fruit", and refers to the upturned wedge-shaped follicles. Common names include Dallachy's banksia and blue banksia.
The current 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...
arrangement of the Banksia genus is based on botanist Alex George
Alex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...
's 1999 monograph for the Flora of Australia
Flora of Australia (series)
The Flora of Australia is a 59 volume series describing the vascular plants, bryophytes and lichens present in Australia and its external territories...
book series. In this arrangement, B. plagiocarpa is placed in Banksia subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
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 its inflorescences take the form of Banksia
Section (botany)
In botany, a section is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section, and the rank of series, if present, is below the section. Sections are typically used to help organise very large genera, which may have hundreds of species...
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 of its straight styles, and series
Series (botany)
Series is a low-level taxonomic rank below that of section but above that of species.In botany, a series is a subdivision of a genus...
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:...
because its inflorescences are cylindrical. George held it to be most closely related to Banksia oblongifolia
Banksia oblongifolia
The Fern-leaved Banksia is a species of shrub in the plant genus Banksia. It occurs along the eastern coast of Australia from Wollongong, New South Wales in the south to Rockhampton, Queensland in the north...
, which he noted often had flower spikes that were tinged blue-grey in bud, and also have affinities to the co-occurring species Banksia aquilonia
Banksia aquilonia
Banksia aquilonia is a species of tall shrub or tree in the plant genus Banksia.-Description:B. aquilonia grows as a tall shrub or small tree up to 8 metres high. It has hard, fissured, grey bark, and elliptic leaves without serrated margins...
In a 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....
cladistic analysis published in 1994, 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...
placed it in the newly described subseries Acclives, within the series Salicinae. It appeared to be the earliest offshoot of the group, which also consisted of B. oblongifolia, B. dentata
Banksia dentata
The Tropical Banksia is a species of small tree in the plant genus Banksia.-Distribution and habitat:It occurs throughout northern Australia, and also extends into New Guinea and the Aru Islands...
and B. robur
Banksia robur
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...
. However, this subgrouping of the Salicinae was not supported by George.
B. plagiocarpa
- Genus BanksiaBanksiaBanksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. When it comes to size, banksias range from prostrate woody shrubs to trees up...
- Subgenus
Banksia subg. IsostylisBanksia subg. Isostylis is a subgenus of Banksia. It contains three closely related species, all of which occur only in Southwest Western Australia. Members of subgenus Isostylis have dome-shaped flower heads that are superficially similar to those of B. ser... - Subgenus 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...
- Section OncostylisBanksia sect. OncostylisBanksia sect. Oncostylis is one of four sections of subgenus Banksia subg. Banksia. It contains those Banksia species with hooked pistils. All of the species in Oncostylis also exhibit a top-down sequence of flower anthesis, except for Banksia nutans which is bottom-up.Banksia sect...
- Section CoccineaBanksia coccineaBanksia coccinea, commonly known as the Scarlet Banksia, Waratah Banksia or Albany Banksia, is an erect shrub or small tree in the plant genus Banksia...
- Section 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...
- Series
Banksia ser. GrandesBanksia ser. Grandes is a taxonomic series in the genus Banksia. It consists of two closely related species in section Banksia, both endemic to Western Australia. These are B. grandis and B. solandri .... - Series BanksiaBanksia ser. BanksiaBanksia ser. Banksia is avalid botanic name for a series of Banksia. As an autonym, it necessarily contains the type species of Banksia, B. serrata . Within this constraint, however, there have been various circumscriptions.-According to Bentham:Banksia ser. Banksia originated in 1870 as...
- Series CrocinaeBanksia ser. CrocinaeBanksia ser. Crocinae is a taxonomic series in the genus Banksia. It consists of four closely related species, all of which are endemic to Western Australia; namely B. prionotes , B. burdettii , B. hookeriana and B. victoriae...
- Series ProstrataeBanksia ser. ProstrataeBanksia ser. Prostratae is a taxonomic series in the genus Banksia. It consists of six closely related species in section Banksia, all endemic to Western Australia, with a prostrate habit.Banksia ser...
- Series 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....
- Series TetragonaeBanksia ser. TetragonaeBanksia ser. Tetragonae is a taxonomic series in the genus Banksia. It consists of three closely related species of erect shrub with pendulous inflorescences in section Banksia. These are B. lemanniana , B. caleyi and B. aculeata ....
- Series Bauerinae
- Series QuercinaeBanksia ser. QuercinaeBanksia ser. Quercinae is avalid botanic name for a series of Banksia. First published by Carl Meissner in 1856, the name has had three circumscriptions.-According to Meissner:...
- Series SalicinaeBanksia ser. SalicinaeBanksia 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:...
- B. dentataBanksia dentataThe Tropical Banksia is a species of small tree in the plant genus Banksia.-Distribution and habitat:It occurs throughout northern Australia, and also extends into New Guinea and the Aru Islands...
– B. aquiloniaBanksia aquiloniaBanksia aquilonia is a species of tall shrub or tree in the plant genus Banksia.-Description:B. aquilonia grows as a tall shrub or small tree up to 8 metres high. It has hard, fissured, grey bark, and elliptic leaves without serrated margins...
– B. integrifoliaBanksia integrifoliaBanksia integrifolia, commonly known as Coast Banksia, is a species of tree that grows along the east coast of Australia. One of the most widely distributed Banksia species, it occurs between Victoria and Central Queensland in a broad range of habitats, from coastal dunes to mountains...
– B. plagiocarpa – B. oblongifoliaBanksia oblongifoliaThe Fern-leaved Banksia is a species of shrub in the plant genus Banksia. It occurs along the eastern coast of Australia from Wollongong, New South Wales in the south to Rockhampton, Queensland in the north...
– B. roburBanksia roburBanksia 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...
– B. confertaBanksia confertaThe Glasshouse Banksia is a species of montane shrub or small tree in the plant genus Banksia. It occurs as distinct subspecies in two widely separated locations: B. conferta subsp. conferta in southern Queensland on the Lamington Plateau and further north in the Glass House Mountains; and...
– B. paludosaBanksia paludosaBanksia paludosa, commonly known as the marsh or swamp banksia, is a species of shrub in the plant genus Banksia. It is endemic to New South Wales, where it is found between Sydney and Batemans Bay, with an isolate population further south around Eden...
– B. marginataBanksia marginataBanksia 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...
– B. caneiBanksia caneiThe mountain banksia is a species of shrub in the plant genus Banksia. It occurs in subalpine areas of the Great Dividing Range between Melbourne and Canberra in southeastern Australia...
– B. saxicolaBanksia saxicolaBanksia saxicola, commonly known as the 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....
- B. dentata
- Section Oncostylis
Distribution and habitat
The range of Banksia plagiocarpa is limited to Hinchinbrook IslandHinchinbrook Island
Hinchinbrook Island lies east of Cardwell and north of Lucinda, Queensland Australia. Hinchinbrook Island is part of the Great Barrier Reef Marine Park and wholly protected within the Hinchinbrook Island National Park, except for a small resort. It is the largest island on the Great Barrier Reef...
, where it is found on the top and slopes of Mount Bowen
Mount Bowen (Queensland)
Mount Bowen is a mountain located on Hinchinbrook Island, off the north east coast of Queensland, Australia. It rises out of the Coral Sea.On this mountain in April 1997, hiker Warren MacDonald became trapped beneath a one-ton slab of stone in a freak rock fall. Two days later he was rescued, only...
and Nina Peak, and the adjacent mainland on the Queensland north coast, where it is found on the summit and slopes of Bishops Peak. The annual rainfall is 2400 mm (95 in). The habitat is either open woodland or grassland, and it can be the dominant shrub. The altitude it grows at on Hinchinbrook is between 200 and 720 m (650–2200 ft), on gravelly, rocky or clay soils, and in association with such plants as Leptospermum polygalifolium
Leptospermum polygalifolium
Leptospermum polygalifolium, commonly known as tantoon, is a shrub species that is native to eastern Australia. It was first described by Salisbury in 1797. L. flavescens as described by Smith in 1797 is a junior synonym....
and she-oaks (Casuarina
Casuarina
Casuarina is a genus of 17 species in the family Casuarinaceae, native to Australasia, southeast Asia, and islands of the western Pacific Ocean. It was once treated as the sole genus in the family, but has been split into three genera .They are evergreen shrubs and trees growing to 35 m tall...
), as well as Banksia aquilonia
Banksia aquilonia
Banksia aquilonia is a species of tall shrub or tree in the plant genus Banksia.-Description:B. aquilonia grows as a tall shrub or small tree up to 8 metres high. It has hard, fissured, grey bark, and elliptic leaves without serrated margins...
at lower altitudes below 400 m (1200 ft). On the mainland, it is found in a more sandy soil, often near water.