Banksia verticillata
Encyclopedia
Banksia verticillata, commonly known as Granite Banksia or Albany Banksia, is a species of shrub
or (rarely) tree of the genus Banksia
in the Proteaceae
family. It is native to the southwest of Western Australia
and can reach up to 3 m (10 ft) in height. It can grow taller to 5 m (15 ft) in sheltered areas, and much smaller in more exposed areas. This species has elliptic green leaves and large, bright golden yellow inflorescence
s or flower spikes, appearing in summer and autumn. The New Holland Honeyeater
(Phylidonyris novaehollandiae) is the most prominent pollinator
, although several other species of honeyeater
, as well as bees, visit the flower spikes.
A declared Vulnerable species, it occurs in two disjunct
populations on granite
outcrops along the south coast of Western Australia
, with the main population near Albany
and a smaller population near Walpole
, and is threatened by dieback (Phytophthora cinnamomi
) and aerial canker (Zythiostroma
). Banksia verticillata is killed by bushfire and new plants regenerate from seed afterwards. Populations take over a decade to produce seed and fire intervals of greater than twenty years are needed to allow the canopy seed bank
to accumulate.
habit in highly exposed areas which are blasted by high wind, or occasionally grow as a single-trunked tree. The rough grey bark has fissures, the stems and branches are finely hairy when young and become smooth with age. The leathery bright green leaves are arranged whorled, or alternately on branches, and are borne on 0.5–1.1 mm long petioles
. They measure 3–9 cm (1.4–3.8 in) in length, and 0.7–1.2 cm (0.3–0.5 in) in width, and are elliptic
in shape with entire (straight) recurved margins. They are initially hairy and become smooth with maturity, although their undersides remain covered with white hair. The golden-yellow inflorescence
s appear in summer and autumn (January to April) and are 8–20 cm (3–8 in) high and 6.5 cm (2.6 in) wide. The smooth pistils are 3–3.5 cm long and hooked at the end. Individual flowers open from the base of the flower spike, the wave of anthesis
moving up the inflorescence. Occasionally, flowers on exposed parts may open early. It takes around 9.5 days for all flowers to open, and rates are similar during the day and night. The inflorescences age to grey and the individual old flowers linger for some time before falling. Up to 100 small woody follicles
may follow on old flower spikes. Measuring 1.1–1.5 cm wide, 3–4 mm wide, and jutting out 2–3 mm from the spike, they open after several years, releasing the seed. Follicles more commonly appear in the middle third of the spike. The reasons for this are unknown, although timing of visits by pollinators or some anatomical factor may be relevant.
during the visit of the Vancouver Expedition
to King George Sound
in September and October 1791. As a result of this collection the species was introduced into cultivation in England, yet it did not result in formal publication of the species.
The next known collection was in December 1801, during the visit of HMS Investigator to King George Sound. Little is known of the circumstances of this collection, other than what is written on the specimen label: "King Georges Sound Dec[embe]r 1801". The specimen is credited to Robert Brown
, but gardener Peter Good
and the botanical artist Ferdinand Bauer
also contributed to Brown's specimen collection, often without attribution. A more precise date and location cannot be given, as neither Brown nor Good mentions the collection in his diary. Bauer did not publish an illustration of the species and his original field sketches are lost, but William Westall
appears to have incorporated it into two of his field sketches, and certainly included it in the foreground of one of the oil painting
s that he later worked up for the Admiralty
.
Brown formally described and named the species in his 1810 On the Proteaceae of Jussieu. He did not identify a type specimen, but the one specimen in his collection has since been formally declared the lectotype
for the species. He also did not explicitly give an etymology
for the specific epithet, but it is accepted that the name derives from the Latin
verticillatus ("whorled"), in reference to the whorled leaf arrangement.
No subspecies
or varieties of Banksia verticillata have been identified; it has no taxonomic synonyms; and its only nomenclatural synonym is Sirmuellera verticillata (R.Br.) Kuntze, which arose from Otto Kuntze
's unsuccessful 1891 attempt to replace Banksia with the new name Sirmuellera.
, B. verticillata was placed between B. compar (now B. integrifolia subsp. compar
) and B. coccinea
(Scarlet Banksia) in phyletic order. No infrageneric arrangement was provided other than the removal of one distinctive species into a subgenus of its own, because of its unusual domed flower head. As B. verticillata flowers occur in characteristic flower spikes, it was retained in Banksia verae, the "true banksias". Banksia verae was renamed Eubanksia by Austrian botanist Stephan Endlicher
in 1847, with B. verticillata remaining between the same two species as in Brown's sequence. A more detailed arrangement
was published by Carl Meissner
in 1856. Eubanksia was demoted to sectional rank, and divided it into four series. B. verticillata was placed in series Salicinae
because its leaves are more or less linear, and have white undersides. Based as they were on leaf characters, Meissner's series were highly heterogeneous, and George Bentham
discarded them all in his 1870 revision of Banksia
. B. verticillata was instead placed in a new section, Oncostylis
, because of its hooked styles. This arrangement would stand for over a century.
For many years there was confusion between B. verticillata and B. littoralis
(Swamp Banksia). Until 1984, the latter was circumscribed as encompassing what is now Banksia seminuda
(River Banksia), which has whorled leaves like B. verticillata. Thus it was easy to perceive B. verticillata as falling within the range of variation of this broadly defined species. The confusion was largely cleared up once B. seminuda was recognised as a distinct taxon
.
Alex George
published a new taxonomic
arrangement of Banksia in his landmark 1981 monograph The genus Banksia L.f. (Proteaceae)
. Endlicher's Eubanksia became B. subg. Banksia
, and was divided into three sections, one of which was Oncostylis. Oncostylis was further divided into four series, with B. verticillata placed in series Spicigerae
because its inflorescences are cylindrical.
In 1996, Kevin Thiele
and Pauline Ladiges published a new arrangement for the genus, after cladistic
analyses yielded a cladogram
significantly different to George's arrangement. With respect to B. verticillata, their findings largely accorded with George's arrangement: section Oncostylis was discarded as polyphyletic, but series Spicigerae was inferred to be monophyletic, and B. verticillata appeared in a succession of clade
s with the species previously identified as its closest relatives: first B. littoralis, then B. seminuda, then B. brownii, and finally B. occidentalis
(Red Swamp Banksia):
This clade became the basis of Thiele and Ladiges' B. subser. Occidentales, which was defined as "characterised by opposite-decussate seedling leaves and adult leaves in true whorls." This arrangement stood until 1999, when George largely reverted to his 1981 arrangement in his monograph for the Flora of Australia
series. Under George's taxonomic arrangement of Banksia
, B. verticillata's taxonomic placement may be summarised as follows:
More recent molecular research by Austin Mast
and colleagues provide further support of B. verticillata's placement among its nearest relatives, but these do not appear to be closely related to the remaining members of B. ser. Spicigerae, but rather occur in a clade that is sister (next closest relative) to B. nutans
:
(B. seminuda is omitted because it was not sampled in the study, not because it occurs elsewhere in the cladogram.)
, and the other around Albany
and eastwards to Cheynes Beach. All but one are located within 2 km (1.5 mi) of the coast, the exception is less than 10 km (6 mi) inland. Plants grow on exposed coastal granite
outcrops, often in cracks within boulders as well as shallow rocky soils. It is the only Banksia which grows exclusively in a granite
soil. It grows in association with Taxandria marginata
, Western Australian Peppermint (Agonis flexuosa
), Andersonia sprengelioides
and species of Hakea
in scrub
and heath
.
(Phylidonyris novaehollandiae) is a major visitor and pollinator of Banksia verticillata. These birds can travel 15 m (50 ft) between inflorescences in a feeding session, and preferentially choose flower spikes with partly opened flowers. Other honeyeater species observed, the White-cheeked Honeyeater
(Phylidonyris nigra) and Western Spinebill
(Acanthorhynchus superciliosus), visit this species to a much lesser extent. The Brown Honeyeater
(Lichmera indistincta) has also been recorded as a visitor. Small mammals are not major pollinators, although Bush Rat
s (Rattus fuscipes) and House Mice
(Mus musculus) have been recorded. Honey Bee
s (Apis mellifera) visit flower spikes but are not effective pollinators.
Banksia verticillata is significantly threatened by at least three microorganisms. Several populations have reduced or vanished from dieback (Phytophthora cinnamomi
), such as those at Two Peoples Bay Nature Reserve
and Gull Rock National Park
. The honey fungus Armillaria luteobubalina
has killed plants in Torndirrup National Park
, and aerial canker (Zythiostroma
) has decimated populations at Waychinicup National Park
east of Albany.
Banksia verticillata plants are generally killed by fire and regenerate from seed. A field study after a mild fire in Torndirrup National Park
published in 1994 found that plants burnt by fire were ten times as likely to have seedlings come up under their crown as unburnt plants (with an average of 25.2 seedlings per burnt plant), and burnt spikes released double the number of seeds as unburnt spikes. Despite this, interfire recruitment (seedlings arising between fires) has also been recorded, and might be more common than in other Banksia species. Observations at several of the populations showed many plants produced their first seed anywhere from 13 to 17 years of age, leading to a recommendation of 20 years between fires to allow seed banks to accumulate. If fire occurs too frequently, plants are burned before reaching maturity or before they have produced sufficient seed to ensure regeneration of the population. This may cause a population decline or even local extinction. Too long a time between fires also causes population decline, as more plants die of natural attrition without releasing their seed, resulting in seed wastage.
, and Rare under Western Australia's Wildlife Conservation Act 1950
. A 1995 census yielded an estimated total population size of 4500 plants. Apart from dieback and aerial canker, frequency of bushfires and illegal picking have been cited as threats. Ongoing management includes monitoring of current populations, gathering more data on best response to fire, and restricting access to populations. Seed has been collected from many populations, but germination rates after ten years of storage are much lower than in Banksia brownii
. Translocation
is considered an option in the future, as is spraying with phosphite
, particularly in the vicinity of Walpole
. Used successfully on B. brownii but as yet untrialled with B. verticillata, phosphite boosts the resistance of both infected and uninfected plants, and also acts as a direct fungicide
. Aerial spraying of phosphite boosts plant survival and slows the spread of infection, but must be carefully managed as studies have shown that foliar spraying of phosphite adversely affects root and shoot growth.
successfully onto Banksia integrifolia
. Seeds do not require any treatment, and take 19 to 49 days to germinate.
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...
or (rarely) tree of 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...
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. It is native to the southwest 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...
and can reach up to 3 m (10 ft) in height. It can grow taller to 5 m (15 ft) in sheltered areas, and much smaller in more exposed areas. This species has elliptic green leaves and large, bright golden 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, appearing in summer and autumn. 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) is the most prominent pollinator
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
, although several other 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...
, as well as bees, visit the flower spikes.
A declared Vulnerable species, it occurs in two disjunct
Disjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
populations on granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
outcrops along the south coast 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...
, with the main population near Albany
Albany, Western Australia
Albany is a port city in the Great Southern region of Western Australia, some 418 km SE of Perth, the state capital. As of 2009, Albany's population was estimated at 33,600, making it the 6th-largest city in the state....
and a smaller population near Walpole
Walpole, Western Australia
Walpole is a town in Western Australia, 432 km SSE of Perth and 66 km west of Denmark.Walpole lies very close to the northern point of the 100-hectare Walpole Inlet, from which it takes its name....
, and is threatened by dieback (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...
) and aerial canker (Zythiostroma
Zythiostroma
Zythiostroma is a genus of canker fungus in the Nectriaceae family. The two or three species in the genus, which are anamorphs of the genus Nectria, have been found in Europe and Java.-Taxonomy:...
). Banksia verticillata is killed by bushfire and new plants regenerate from seed afterwards. Populations take over a decade to produce seed and fire intervals of greater than twenty years are needed to allow the canopy seed bank
Canopy seed bank
A canopy seed bank or aerial seed bank is the aggregate of viable seed stored by a plant in its canopy. Canopy seed banks occur in plants that postpone seed release for some reason....
to accumulate.
Description
Banksia verticillata grows as a spreading, bushy shrub with many branches up to 3 m (10 ft) high, but can reach 5 m (15 ft) high in sheltered locations. It may be much lower or even adopt a prostrateProstrate shrub
A prostrate shrub is a woody plant, most of the branches of which lie upon or just under the ground, rather than being held erect as are the branches of most trees and shrubs....
habit in highly exposed areas which are blasted by high wind, or occasionally grow as a single-trunked tree. The rough grey bark has fissures, the stems and branches are finely hairy when young and become smooth with age. The leathery bright green leaves are arranged whorled, or alternately on branches, and are borne on 0.5–1.1 mm long petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. They measure 3–9 cm (1.4–3.8 in) in length, and 0.7–1.2 cm (0.3–0.5 in) in width, and are elliptic
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
in shape with entire (straight) recurved margins. They are initially hairy and become smooth with maturity, although their undersides remain covered with white hair. The golden-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 appear in summer and autumn (January to April) and are 8–20 cm (3–8 in) high and 6.5 cm (2.6 in) wide. The smooth pistils are 3–3.5 cm long and hooked at the end. Individual flowers open from the base of the flower spike, the wave of 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...
moving up the inflorescence. Occasionally, flowers on exposed parts may open early. It takes around 9.5 days for all flowers to open, and rates are similar during the day and night. The inflorescences age to grey and the individual old flowers linger for some time before falling. Up to 100 small 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....
may follow on old flower spikes. Measuring 1.1–1.5 cm wide, 3–4 mm wide, and jutting out 2–3 mm from the spike, they open after several years, releasing the seed. Follicles more commonly appear in the middle third of the spike. The reasons for this are unknown, although timing of visits by pollinators or some anatomical factor may be relevant.
Discovery and naming
The earliest known botanical collection of B. verticillata was made by Scottish surgeon and naturalist Archibald MenziesArchibald Menzies
Archibald Menzies was a Scottish surgeon, botanist and naturalist.- Life and career :Menzies was born at Easter Stix in the parish of Weem, in Perthshire. While working with his elder brother William at the Royal Botanic Gardens, he drew the attention of Dr John Hope, professor of botany at...
during the visit of the Vancouver Expedition
Vancouver Expedition
The Vancouver Expedition was a four-and-a-half-year voyage of exploration and diplomacy, commanded by Captain George Vancouver. The expedition circumnavigated the globe, touched five continents and changed the course of history for the indigenous nations and several European empires and their...
to 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 September and October 1791. As a result of this collection the species was introduced into cultivation in England, yet it did not result in formal publication of the species.
The next known collection was in December 1801, during the visit of HMS Investigator to King George Sound. Little is known of the circumstances of this collection, other than what is written on the specimen label: "King Georges Sound Dec[embe]r 1801". The specimen is credited to 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...
, but gardener Peter Good
Peter Good
Peter Good was the gardener assistant to botanist Robert Brown on the voyage of HMS Investigator under Matthew Flinders, during which the coast of Australia was charted, and various plants collected.-Biography:...
and the botanical artist Ferdinand Bauer
Ferdinand Bauer
Ferdinand Lucas Bauer was an Austrian botanical illustrator who travelled on Matthew Flinders' expedition to Australia.-Biography:...
also contributed to Brown's specimen collection, often without attribution. A more precise date and location cannot be given, as neither Brown nor Good mentions the collection in his diary. Bauer did not publish an illustration of the species and his original field sketches are lost, but William Westall
William Westall
William Bury Westall was an English novelist born in Old Accrington, Lancashire, England.Originally a businessman, he later became a journalist who also wrote about 30 pot-boiler romantic novels with titles including The Old Factory, Strange Crimes and Her Ladyship's Secret...
appears to have incorporated it into two of his field sketches, and certainly included it in the foreground of one of the oil painting
Oil painting
Oil painting is the process of painting with pigments that are bound with a medium of drying oil—especially in early modern Europe, linseed oil. Often an oil such as linseed was boiled with a resin such as pine resin or even frankincense; these were called 'varnishes' and were prized for their body...
s that he later worked up for the Admiralty
Admiralty
The Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...
.
Brown formally described and named the species in his 1810 On the Proteaceae of Jussieu. He did not identify a type specimen, but the one specimen in his collection has since been formally declared the lectotype
Lectotype
In botanical nomenclature and zoological nomenclature, a lectotype is a kind of name-bearing type. When a species was originally described on the basis of a name-bearing type consisting of multiple specimens, one of those may be designated as the lectotype...
for the species. He also did not explicitly give an etymology
Etymology
Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...
for the specific epithet, but it is accepted that the name derives from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
verticillatus ("whorled"), in reference to the whorled leaf arrangement.
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 of Banksia verticillata have been identified; it has no taxonomic synonyms; and its only nomenclatural synonym is Sirmuellera verticillata (R.Br.) Kuntze, which arose from 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...
's unsuccessful 1891 attempt to replace Banksia with the new name Sirmuellera.
Infrageneric placement
In Brown's arrangement of BanksiaBrown's taxonomic arrangement of Banksia
Robert Brown's taxonomic arrangement of Banksia was published in his 1810 Prodromus Florae Novae Hollandiae et Insulae Van Diemen, and expanded in this 1830 supplement to that publication, Supplementum Primum Prodromi Florae Novae Hollandiae...
, B. verticillata was placed between B. compar (now B. integrifolia subsp. compar
Banksia integrifolia subsp. compar
Banksia integrifolia subsp. compar is a subspecies of Banksia integrifolia. It has larger, glossier leaves than other subspecies, and occurs much further north.-Description:...
) and B. coccinea
Banksia coccinea
Banksia coccinea, commonly known as the Scarlet Banksia, Waratah Banksia or Albany Banksia, is an erect shrub or small tree in the plant genus Banksia...
(Scarlet Banksia) in phyletic order. No infrageneric arrangement was provided other than the removal of one distinctive species into a subgenus of its own, because of its unusual domed flower head. As B. verticillata flowers occur in characteristic flower spikes, it was retained in Banksia verae, the "true banksias". Banksia verae was renamed Eubanksia by Austrian botanist Stephan Endlicher
Stephan Ladislaus Endlicher
Stephan Ladislaus Endlicher was an Austrian botanist, numismatist and Sinologist. He was a director of the Botanical Garden of Vienna. He was born in Pressburg and died in Vienna....
in 1847, with B. verticillata remaining between the same two species as in Brown's sequence. A more detailed 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...
was published by 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...
in 1856. Eubanksia was demoted to sectional rank, and divided it into four series. B. verticillata was placed 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:...
because its leaves are more or less linear, and have white undersides. Based as they were on leaf characters, Meissner's series were highly heterogeneous, and 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 :...
discarded them all in his 1870 revision of Banksia
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...
. B. verticillata was instead placed in a new section, Oncostylis
Banksia sect. Oncostylis
Banksia sect. Oncostylis is one of four sections of subgenus Banksia subg. Banksia. It contains those Banksia species with hooked pistils. All of the species in Oncostylis also exhibit a top-down sequence of flower anthesis, except for Banksia nutans which is bottom-up.Banksia sect...
, because of its hooked styles. This arrangement would stand for over a century.
For many years there was confusion between B. verticillata and B. littoralis
Banksia littoralis
Banksia littoralis, commonly known as the Swamp Banksia, Swamp Oak, Pungura and the Western Swamp Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from the south eastern metropolitan area of Perth to the Stirling Range and Albany...
(Swamp Banksia). Until 1984, the latter was circumscribed as encompassing what is now Banksia seminuda
Banksia seminuda
Banksia seminuda, commonly known as the River Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from Dwellingup to the Broke Inlet east of Denmark . It is often mistaken for and was originally considered a subspecies of the Banksia littoralis...
(River Banksia), which has whorled leaves like B. verticillata. Thus it was easy to perceive B. verticillata as falling within the range of variation of this broadly defined species. The confusion was largely cleared up once B. seminuda was recognised as a distinct taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
.
Alex George
Alex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...
published a new taxonomic
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 Banksia in his landmark 1981 monograph The genus Banksia L.f. (Proteaceae)
The genus Banksia L.f. (Proteaceae)
The genus Banksia L.f. is a 1981 monograph by Alex George on the taxonomy of the plant genus Banksia. Published by the Western Australian Herbarium as Nuytsia 3, it presented George's taxonomic arrangement of Banksia, the first major taxonomic revision of the genus since George Bentham published...
. Endlicher's Eubanksia became B. subg. Banksia
Banksia subg. Banksia
Banksia subg. Banksia is a valid botanic name for a subgenus of Banksia. As an autonym, it necessarily contains the type species of Banksia, B. serrata . Within this constraint, however, there have been various circumscriptions.-Banksia verae:B. subg...
, and was divided into three sections, one of which was Oncostylis. Oncostylis was further divided into four series, with B. verticillata placed in series Spicigerae
Banksia ser. Spicigerae
Banksia ser. Spicigerae is a taxonomic series in the genus Banksia. It consists of the seven species in section Oncostylis that have cylindrical inflorescences. These range in form from small shrubs to tall trees. The leaves grow in either an alternate or whorled pattern, with various shape forms...
because its inflorescences are cylindrical.
In 1996, Kevin Thiele
Kevin Thiele
Kevin R. Thiele is curator of the Western Australian Herbarium. His research interests include the systematics of the plant families Proteaceae, Rhamnaceae and Violaceae, and the conservation ecology of grassy woodland ecosystems...
and Pauline Ladiges published a new arrangement for the genus, after cladistic
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
analyses yielded a cladogram
Cladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
significantly different to George's arrangement. With respect to B. verticillata, their findings largely accorded with George's arrangement: section Oncostylis was discarded as polyphyletic, but series Spicigerae was inferred to be monophyletic, and B. verticillata appeared in a succession of 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...
s with the species previously identified as its closest relatives: first B. littoralis, then B. seminuda, then B. brownii, and finally B. occidentalis
Banksia occidentalis
The Red Swamp Banksia or Waterbush is a species of shrub or small tree in the plant genus Banksia. It occurs on the south coast of Western Australia in three disjunct populations: at Augusta, around Albany and in the Esperance area.A 1980 field study at Cheyne beach showed it to be pollinated by...
(Red Swamp Banksia):
This clade became the basis of Thiele and Ladiges' B. subser. Occidentales, which was defined as "characterised by opposite-decussate seedling leaves and adult leaves in true whorls." This arrangement stood until 1999, when George largely reverted to his 1981 arrangement in his monograph for the Flora of Australia
Flora of Australia (series)
The Flora of Australia is a 59 volume series describing the vascular plants, bryophytes and lichens present in Australia and its external territories...
series. Under George's taxonomic arrangement of Banksia
George's taxonomic arrangement of Banksia
Alex George's taxonomic arrangement of Banksia was the first modern-day arrangement for that genus. First published in 1981 in the classic monograph The genus Banksia L.f. , it superseded the arrangement of George Bentham, which had stood for over a hundred years. It was overturned in 1996 by Kevin...
, B. verticillata's taxonomic placement 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...
(9 series, 50 species, 9 subspecies, 3 varieties) - B. sect. Coccinea (1 species)
- B. sect. 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...
- B. ser. SpicigeraeBanksia ser. SpicigeraeBanksia ser. Spicigerae is a taxonomic series in the genus Banksia. It consists of the seven species in section Oncostylis that have cylindrical inflorescences. These range in form from small shrubs to tall trees. The leaves grow in either an alternate or whorled pattern, with various shape forms...
(7 species, 2 subspecies, 4 varieties)- B. spinulosaBanksia spinulosaThe Hairpin Banksia is a species of woody shrub, of the genus Banksia in the Proteaceae family, native to eastern Australia. Widely distributed, it is found as an understorey plant in open dry forest or heathland from Victoria to northern Queensland, generally on sandstone though sometimes also...
(4 varieties) - B. ericifoliaBanksia ericifoliaBanksia ericifolia, the Heath-leaved Banksia , is a species of woody shrub of the Proteaceae family native to Australia. It grows in two separate regions of Central and Northern New South Wales east of the Great Dividing Range...
(2 subspecies) - B. verticillata
- B. seminudaBanksia seminudaBanksia seminuda, commonly known as the River Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from Dwellingup to the Broke Inlet east of Denmark . It is often mistaken for and was originally considered a subspecies of the Banksia littoralis...
- B. littoralisBanksia littoralisBanksia littoralis, commonly known as the Swamp Banksia, Swamp Oak, Pungura and the Western Swamp Banksia, is a tree in the plant genus Banksia. It is found in south west Western Australia from the south eastern metropolitan area of Perth to the Stirling Range and Albany...
- B. occidentalisBanksia occidentalisThe Red Swamp Banksia or Waterbush is a species of shrub or small tree in the plant genus Banksia. It occurs on the south coast of Western Australia in three disjunct populations: at Augusta, around Albany and in the Esperance area.A 1980 field study at Cheyne beach showed it to be pollinated by...
- B. browniiBanksia browniiBanksia brownii, commonly known as Feather-leaved Banksia or Brown's Banksia, is a species of shrub that occurs in southwest Western Australia. An attractive plant with fine feathery leaves and large red-brown flower spikes, it usually grows as an upright bush around two metres high, but can also...
- B. spinulosa
- B. ser. Tricuspidae (1 species)
- B. ser. DryandroideaeBanksia ser. DryandroideaeBanksia ser. Dryandroideae is a valid botanic name for a taxonomic series in the plant genus Banksia. First published by Carl Meissner in 1856, the name has had two circumscriptions. As presently circumscribed it is monotypic, containing only B. dryandroides.-According to Meissner:B. ser...
(1 species) - B. ser. AbietinaeBanksia ser. AbietinaeBanksia ser. Abietinae is avalid botanic name for a series of Banksia. First published by Carl Meissner in 1856, the name has had three circumscriptions.-According to Meissner:...
(13 species, 2 subspecies, 9 varieties)
- B. ser. Spicigerae
- B. sect. Banksia
- B. subg. IsostylisBanksia subg. IsostylisBanksia subg. Isostylis is a subgenus of Banksia. It contains three closely related species, all of which occur only in Southwest Western Australia. Members of subgenus Isostylis have dome-shaped flower heads that are superficially similar to those of B. ser...
(3 species)
- B. subg. Banksia
More recent molecular research by 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 colleagues provide further support of B. verticillata's placement among its nearest relatives, but these do not appear to be closely related to the remaining members of B. ser. Spicigerae, but rather occur in a clade that is sister (next closest relative) to B. nutans
Banksia nutans
Banksia nutans, commonly known as Nodding Banksia, is a species of shrub native to the south coast of Western Australia in the genus Banksia...
:
(B. seminuda is omitted because it was not sampled in the study, not because it occurs elsewhere in the cladogram.)
Distribution and habitat
Banksia verticillata is found in scattered populations in two disjunct segments: one clustered around WalpoleWalpole, Western Australia
Walpole is a town in Western Australia, 432 km SSE of Perth and 66 km west of Denmark.Walpole lies very close to the northern point of the 100-hectare Walpole Inlet, from which it takes its name....
, and the other 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....
and eastwards to Cheynes Beach. All but one are located within 2 km (1.5 mi) of the coast, the exception is less than 10 km (6 mi) inland. Plants grow on exposed coastal granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
outcrops, often in cracks within boulders as well as shallow rocky soils. It is the only Banksia which grows exclusively in a granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
soil. It grows in association with Taxandria marginata
Taxandria marginata
Taxandria marginata is a species of tree that grows in the south west corner of Western Australia. This plant was previously classified as Agonis marginata but was reclassified by Wheeler and Marchant into the new genus Taxandria in a 2007 revision....
, Western Australian Peppermint (Agonis flexuosa
Agonis flexuosa
Agonis flexuosa is a species of tree that grows in the south west of Western Australia. It is easily the most common of the Agonis species, and is one of the most recognisable trees of Western Australia, being commonly grown in parks and on road verges in Perth.The species is commonly known as...
), Andersonia sprengelioides
Andersonia sprengelioides
Andersonia sprengelioides is a species of shrub that grows in the south west corner of Western Australia. It was originally described by the botanist Robert Brown in 1810 and retains its original name. The genus Andersonia is classified in the Ericaceae, or in the family Epacridaceae ....
and species of Hakea
Hakea
Hakea is a genus of 149 species of shrubs and small trees in the Proteaceae, native to Australia. They are found throughout the country, with the highest species diversity being found in the south west of Western Australia....
in scrub
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...
and heath
Heath (habitat)
A heath or heathland is a dwarf-shrub habitat found on mainly low quality acidic soils, characterised by open, low growing woody vegetation, often dominated by plants of the Ericaceae. There are some clear differences between heath and moorland...
.
Ecology
The New Holland HoneyeaterNew 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) is a major visitor and pollinator of Banksia verticillata. These birds can travel 15 m (50 ft) between inflorescences in a feeding session, and preferentially choose flower spikes with partly opened flowers. Other honeyeater species observed, the White-cheeked Honeyeater
White-cheeked Honeyeater
The White-cheeked Honeyeater inhabits the east coast and the south-west corner of Australia. It has a large white patch on its cheek, a brown eye, and a yellow panel on its wing.- Description :...
(Phylidonyris nigra) and 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), visit this species to a much lesser extent. The 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) has also been recorded as a visitor. Small mammals are not major pollinators, although Bush Rat
Bush Rat
The bush rat is a small Australian nocturnal animal. It is an omnivore. It is one of the most common species of rats and is found in many heathland areas of Victoria and NSW...
s (Rattus fuscipes) and House Mice
House mouse
The house mouse is a small rodent, a mouse, one of the most numerous species of the genus Mus.As a wild animal the house mouse mainly lives associated with humans, causing damage to crops and stored food....
(Mus musculus) have been recorded. Honey Bee
Honey bee
Honey bees are a subset of bees in the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis...
s (Apis mellifera) visit flower spikes but are not effective pollinators.
Banksia verticillata is significantly threatened by at least three microorganisms. Several populations have reduced or vanished from dieback (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...
), such as those at Two Peoples Bay Nature Reserve
Two Peoples Bay Nature Reserve
Two Peoples Bay is a protected area east of Albany. The area is accessible by 2WD vehicles. The bay itself, including two small secluded beaches, faces due east and is protected from the Southern Ocean by a headland formed by the granite massif of Mount Gardiner...
and Gull Rock National Park
Gull Rock National Park
Gull Rock National Park is a small national park situated 25 km southeast of Albany in Western Australia. It was established in 2006, becoming Western Australia's 97th National Park in the process. It comprises around in area. The area is backed by King George Sound to the south, Oyster...
. The honey fungus Armillaria luteobubalina
Armillaria luteobubalina
Armillaria luteobubalina, commonly known as the Australian honey fungus, is a species of mushroom in the family Physalacriaceae. Widely distributed in southern Australia, the fungus is responsible for a disease known as Armillaria root rot, a primary cause of Eucalyptus tree death and forest dieback...
has killed plants in Torndirrup National Park
Torndirrup National Park
Torndirrup National Park is a national park in the Great Southern region of Western Australia , southeast of Perth and south of Albany. Torndirrup National Park has many impressive rock formations on the coast. These include the Gap, Natural Bridge and the Blowholes all shaped from the local...
, and aerial canker (Zythiostroma
Zythiostroma
Zythiostroma is a genus of canker fungus in the Nectriaceae family. The two or three species in the genus, which are anamorphs of the genus Nectria, have been found in Europe and Java.-Taxonomy:...
) has decimated populations at Waychinicup National Park
Waychinicup National Park
Waychinicup National Park is a in Western Australia , southeast of Perth and east of Albany and extends as far Cheynes Beach near Bremer Bay. Facilities at the park include a camping area and bush toilet near the inlet of the Waychinicup River....
east of Albany.
Banksia verticillata plants are generally killed by fire and regenerate from seed. A field study after a mild fire in Torndirrup National Park
Torndirrup National Park
Torndirrup National Park is a national park in the Great Southern region of Western Australia , southeast of Perth and south of Albany. Torndirrup National Park has many impressive rock formations on the coast. These include the Gap, Natural Bridge and the Blowholes all shaped from the local...
published in 1994 found that plants burnt by fire were ten times as likely to have seedlings come up under their crown as unburnt plants (with an average of 25.2 seedlings per burnt plant), and burnt spikes released double the number of seeds as unburnt spikes. Despite this, interfire recruitment (seedlings arising between fires) has also been recorded, and might be more common than in other Banksia species. Observations at several of the populations showed many plants produced their first seed anywhere from 13 to 17 years of age, leading to a recommendation of 20 years between fires to allow seed banks to accumulate. If fire occurs too frequently, plants are burned before reaching maturity or before they have produced sufficient seed to ensure regeneration of the population. This may cause a population decline or even local extinction. Too long a time between fires also causes population decline, as more plants die of natural attrition without releasing their seed, resulting in seed wastage.
Conservation
Banksia verticillata has been declared Vulnerable under the federal Environment Protection and Biodiversity Conservation Act 1999Environment Protection and Biodiversity Conservation Act 1999
The Environment Protection and Biodiversity Conservation Act 1999 is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and culturally significant places...
, and Rare under Western Australia's Wildlife Conservation Act 1950
Wildlife Conservation Act 1950
The Wildlife Conservation Act 1950 is an act of the Western Australian Parliament that provides the statute relating to conservation and legal protection of flora and fauna....
. A 1995 census yielded an estimated total population size of 4500 plants. Apart from dieback and aerial canker, frequency of bushfires and illegal picking have been cited as threats. Ongoing management includes monitoring of current populations, gathering more data on best response to fire, and restricting access to populations. Seed has been collected from many populations, but germination rates after ten years of storage are much lower than in Banksia brownii
Banksia brownii
Banksia brownii, commonly known as Feather-leaved Banksia or Brown's Banksia, is a species of shrub that occurs in southwest Western Australia. An attractive plant with fine feathery leaves and large red-brown flower spikes, it usually grows as an upright bush around two metres high, but can also...
. Translocation
Translocation (Wildlife conservation)
Translocation in wildlife conservation means capture, transport and release or introduction of species, habitats or other ecological material from one location to another...
is considered an option in the future, as is spraying with phosphite
Phosphite
A phosphite is a salt of phosphorous acid. The phosphite ion is a polyatomic ion with a phosphorus central atom where phosphorus has an oxidation state of +3...
, particularly in the vicinity of Walpole
Walpole, Western Australia
Walpole is a town in Western Australia, 432 km SSE of Perth and 66 km west of Denmark.Walpole lies very close to the northern point of the 100-hectare Walpole Inlet, from which it takes its name....
. Used successfully on B. brownii but as yet untrialled with B. verticillata, phosphite boosts the resistance of both infected and uninfected plants, and also acts as a direct fungicide
Fungicide
Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals...
. Aerial spraying of phosphite boosts plant survival and slows the spread of infection, but must be carefully managed as studies have shown that foliar spraying of phosphite adversely affects root and shoot growth.
Cultivation
Banksia verticillata is seldom seen in cultivation. The natural growing conditions point to a sunny aspect and good drainage as being important in cultivation. It is good for coastal situations and erosion control. Very sensitive to dieback, B. verticillata (like most other western Australian banksias) perishes quickly in humid conditions or poor drainage. It has been graftedGrafting
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...
successfully onto Banksia integrifolia
Banksia integrifolia
Banksia integrifolia, commonly known as Coast Banksia, is a species of tree that grows along the east coast of Australia. One of the most widely distributed Banksia species, it occurs between Victoria and Central Queensland in a broad range of habitats, from coastal dunes to mountains...
. Seeds do not require any treatment, and take 19 to 49 days to germinate.