Taxonomy of Banksia integrifolia

taxobox
name = "Banksia integrifolia"


image_caption = "Banksia integrifolia" subsp. "integrifolia"
status = secure
regnum = Plantae
unranked_divisio = Angiosperms
unranked_classis = Eudicots
ordo = Proteales
familia = Proteaceae
genus = "Banksia"
subgenus = "B." subg. "Banksia"
sectio = "B." sect. "Banksia"
series = "B." ser. "Salicinae"
species = "B. integrifolia"
binomial = "Banksia integrifolia"
binomial_authority = L.f.
subdivision_ranks = Subspecies
subdivision = * "B. i." subsp. "integrifolia"
* "B. i." subsp. "compar"
* "B. i." subsp. "monticola"
synonyms = * "B. i." var. "minor" Meisn.
* "Sirmuellera integrifolia" (L.f.) Kuntze
* "Isostylis integrifolia" (L.f.) Britten|The taxonomy of "Banksia integrifolia" has a long and complex history, the result of confusion caused by the species' great variability, and similarities with some closely related species. The existence of hybrids between "B. integrifolia" and related species as well as early attempts to classify the species based on dried specimen material have also contributed to the confusion.

The species is divided into three subspecies: "B. i." subsp. "compar", "B. i." subsp. "integrifolia", and "B. i." subsp. "monticola". Recent molecular studies support this division.

Until recently, "B. integrifolia"'s taxonomic placement within the genus was largely settled, with the species placed in "Banksia" subg. "Banksia" sect. "Banksia" ser. "Salicinae". DNA analyses have now cast doubt upon this arrangement and the publication of a new arrangement based on phylogenetic considerations has been foreshadowed.

Background

"Banksia integrifolia", commonly known as the Coast Banksia, is 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. It is highly variable in form, but is most often encountered as a tree up to 25 metres (82 ft) in height. Its leaves have dark green upper surfaces and white undersides, a contrast that can be striking on windy days.

A hardy and versatile Australian native plant, "B. integrifolia" is widely planted in domestic gardens. Within its natural distribution it is a popular choice in parks, streetscapes, bush revegetation and stabilisation of dunes. Its hardiness has prompted research into its suitability for use as a rootstock in the cut flower trade, but has also caused concerns about its potential to become a weed outside of its natural habitat.

Discovery

The first botanical collection of "B. integrifolia" was made by Sir Joseph Banks and Dr Daniel Solander, naturalists on the "Endeavour" during Lieutenant (later Captain) James Cook's first voyage to the Pacific Ocean. Cook landed on Australian soil for the first time on 29 April 1770, at a place that he later named Botany Bay in recognition of "the great quantity of plants Mr Banks and Dr Solander found in this place".cite book | author = Cook, James | year = 1893 | editor = William J. L. Wharton (ed.) | title = | location = London | publisher = E. Stock] Over the next seven weeks, Banks and Solander collected thousands of plant specimens, including the first specimens of a new genus that would later be named "Banksia" in Banks' honour.

Every specimen collected during the "Endeavour" voyage was sketched by Banks' botanical illustrator Sydney Parkinson. On the "Endeavour"

's return to England in July 1771, Banks' specimens became part of his London herbarium, and artists were employed to paint watercolours from Parkinson's sketches. Banks had plans to publish his entire collection as "Banks' Florilegium", but for various reasons the project was never completed, and it would be ten years before any of the "Banksia" species were formally published.cite journal | author = Salkin, Alf I. | year = 1981 | title = A short history of the discovery and naming of banksias in Eastern Australia: Part I, Banks and Solander | journal = Victorian Naturalist | volume = 98 | issue = 2]

Early taxonomic history

The genus "Banksia" was eventually described by Carolus Linnaeus the Younger in his April 1782 publication "Supplementum Plantarum". Linnaeus described four "Banksia" species, distinguishing them by their leaf shape, and naming them accordingly. Thus the species with entire leaf margins was given the specific name "integrifolia", from the Latin "integer", meaning "entire", and "folium", meaning "leaf".cite book | author = Carolus Linnaeus the Younger | year = 1782 | title = Supplementum Plantarum | location = Brunsvigae | publisher = Orphanotrophei] The full name of the species is therefore "Banksia integrifolia" L.f."APNI | name = "Banksia integrifolia" L.f. | id = 53918]

Then followed by two centuries of variations to the taxonomic limits of "B. integrifolia". The first sign of confusion was in 1788, when Joseph Gaertner published "B. spicata".cite book | author = Gaertner, Joseph | title = De Fructibus et Seminibus Plantarum | location = Stutgard | publisher = Sumtibus auctoris, typis academiae carolinae] Gaertner did not specify his type material for the taxon, but contemporary material labelled as such clearly belongs to what is now known as "B. i." subsp. "integrifolia".cite journal | author = George, Alex S. | year = 1981 | title = The genus "Banksia" L.f. (Proteaceae) | journal = Nuytsia | volume = 3 | issue = 3 | pages = 239–473 | id = ISSN|0085-4417] In 1810, Robert Brown relegated the name to synonymy with "B. integrifolia",cite book | author = Brown, Robert | year = 1810 | title = Prodromus Florae Novae Hollandiae et Insulae Van Diemen | location = London | publisher = Richard Taylor and Company] and it remained so until 1981 when Alex George refined it to a synonym of the autonym "B. i." var. "integrifolia".

In 1800, Antonio José Cavanilles published a number of new "Banksia" species based on specimens collected at Port Jackson, New South Wales in 1797 by Luis Née, botanist to the Alejandro Malaspina expedition. These included "B. oblongifolia", "B. oleifolia" and "B. glauca". The last two of these were declared synonyms of "B. integrifolia" by Robert Brown in 1810, and refined to synonyms of "B. i." subsp. "integrifolia" by George in 1999.cite encyclopedia | author = George, Alex S. | year = 1999 | title = "Banksia" | url = http://www.anbg.gov.au/abrs/online-resources/flora/stddisplay.xsql?pnid=3381 | accessdate = 2006-10-31 | editor = Wilson, Annette | encyclopedia = [http://www.deh.gov.au/biodiversity/abrs/online-resources/flora/main/index.html Flora of Australia] | volume = Volume 17B: Proteaceae 3: Hakea to Dryandra | pages = 175–251 | location = Collingwood, Victoria | publisher = CSIRO Publishing / Australian Biological Resources Study | id = ISBN 0-643-06454-0] The first was ascribed to "B. i." var. "oblongifolia" by Karel Domin in 1930, but this was overturned by George in 1981, and "B. oblongifolia" remains a current species name.APNI | name = "Banksia oblongifolia" Cav. | id = 54642]

In 1810, Robert Brown described 31 known species of "Banksia" in his "Prodromus Florae Novae Hollandiae et Insulae Van Diemen". He split the genus into two subgenera, placing "B. integrifolia" in subgenus "Banksia verae", the "True Banksias". New species described by Brown included "B. compar", which is now considered a subspecies of "B. integrifolia",APNI | name = "Banksia integrifolia" subsp. "compar" (R.Br.) K.R.Thiele | id = 127460] and "B. paludosa", a close relative of "B. integrifolia" which was for a time considered a variety of it.cite encyclopedia | author = Bentham, George | year = 1870 | title = | encyclopedia = | volume = Volume 5: Myoporineae to Proteaceae | pages = 541–562 | location = London | publisher = L. Reeve & Co.]

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, into four series based on leaf properties. He placed "B. integrifolia" in series "Salicinae", and further divided it into three varieties: "B. i." var. "minor" for specimens with small, entire leaves; "B. i." var. "major" for specimens with larger, somewhat dentate leaves; and "B. integrifola" var "dentata" for specimens with very large dentate leaves. [cite book | author = Meissner, Carl | year = 1856 | chapter = Proteaceae | editor = A. P. de Candolle | title = Prodromus Systematis Naturalis Regni Vegetabilis, Pars Decima Quarta] | location = Paris | publisher = Sumptibus Victoris Masson] However, the second of these varieties was based upon a specimen of "B. integrifolia" with juvenile leaves, and the last was "B. robur". All three were overturned by George in 1981.

In 1870, George Bentham published a thorough revision of the "Banksia" in his landmark publication "Flora Australiensis". In Bentham's arrangement, Meissner's four series were replaced by four sections based on leaf, style and pollen-presenter characters. "B. integrifolia" was placed in section "Eubanksia" along with "B. marginata" and "B. dentata". The number of recognised "Banksia" species was reduced from 60 to 46, with "B. compar" declared a synonym of "B. integrifolia", and "B. paludosa" relegated to a variety of "B. integrifolia". The former taxon is now considered a subspecies of "B. integrifolia", but "B. paludosa" has since been reinstated as a species and remains a current species name.APNI | name = "Banksia paludosa" R.Br. | id = 54772]

A major disruption to "Banksia" nomenclature occurred in 1891, when Otto Kuntze challenged "Banksia" L.f. on the grounds that "Banksia" J.R.Forst & G.Forst had been published before it. Kuntze transferred all "Banksia" taxa to the new name "Sirmuellera"; thus "B. integrifolia" became "Sirmuellera integrifolia" (L.f.) Kuntze.cite book | author = Kuntze, Otto | year = 1891 | title = Revisio Generum Plantarum: Pars II | pages = 581–582 | location = Leipzig | publisher = Arthur Felix] Kuntze's challenge failed, as did a similar challenge by James Britten in 1905. Britten proposed the generic name "Isostylis", republishing "B. integrifolia" as "Isostylis integrifolia" (L.f.) Britten. In 1940 "Banksia" L.f. was formally conserved against future challenges.

20th century

In 1913, Frederick Bailey promoted Brown's "B. compar", which had been declared a synonym of "B. integrifolia" by Bentham in 1870, to variety rank as "B. i." var. "compar". This would be the first infraspecific taxon of "B. integrifolia" to achieve widespread acceptance.APNI | name = "Banksia integrifolia" var. "compar" (R.Br.) F.M.Bailey | id = 53939] The variety was promoted to subspecies rank by Kevin Thiele in 1994,cite journal | author = Thiele, Kevin and Pauline Ladiges | year = 1994 | title = The "Banksia integrifolia" L.f. species complex (Proteaceae) | journal = Australian Systematic Botany | volume = 7 | pages = 393–408 | doi = 10.1071/SB9940393] and "B. i." subsp. "compar" remains a current taxon to date. Under modern botanical nomenclature rules, the publication of subspecies "B. i." subsp. "compar" automatically created the autonym "B. i." subsp. "integrifolia", to encompass the type material.

The most recent classical taxonomic treatment of "Banksia" first appeared in Alex George's 1981 monograph "The genus Banksia L.f. (Proteaceae)". In addition to revising the existing nomenclature, George published a number of new species and subspecies, including a new variety of "B. integrifolia", namely "B. i." var. "aquilonia". This was promoted to subspecific rank by Thiele in 1994, and in 1996 George promoted it to specific rank as "Banksia aquilonia".cite journal | author = George, Alex S. | year = 1996 | title = Notes on "Banksia" L.f. (Proteaceae) | journal = Nuytsia | volume = 11 | issue = 1 | pages = 21–24]

A third subspecific taxon of "B. integrifolia" has its roots in Gwen Harden's 1991 publication "Flora of New South Wales". Harden recognised a new subspecies of "B. integrifolia", but did not give it a name, referring to it only as "B. i." subsp. A".APNI | name = "Banksia integrifolia" subsp. A | id = 262570] Three years later, Thiele confirmed the subspecific rank of this taxon, naming it "B. i." subsp. "monticola".

In 1996, Kevin Thiele and Pauline Ladiges published a new arrangement for "Banksia" after cladistic analyses yielded a cladogram significantly different from George's arrangement. Thiele and Ladiges' arrangement retained "B. integrifolia" in series "Salicinae", but divided the series into two subseries: "B." subser. "Integrifoliae" and "B." subser. "Acclives". The seven members of subseries "Integrifoliae" all appear to be closely related, and natural hybrids have been recorded between members where they co-occur.cite journal | author = Thiele, Kevin and Pauline Y. Ladiges | year = 1996 | title = A cladistic analysis of "Banksia" (Proteaceae) | journal = Australian Systematic Botany | volume = 9 | issue = 5 | pages = 661–733 | doi = 10.1071/SB9960661] This arrangement stood until 1999, when George effectively reverted to his 1981 arrangement in his monograph for the "Flora of Australia" series. He argued that there was insufficient evidence for the division, and that "B. dentata" is clearly allied to "B. integrifolia", not to the very distinctive "B. robur".

George's arrangement

Until recently, the accepted taxonomic arrangement for "Banksia" was that published in George's 1999 monograph for the "Flora of Australia" series. In this arrangement, "B. integrifolia" is placed in "Banksia" subg. "Banksia" because its inflorescences take the form of "Banksia"

's characteristic flower spikes; "Banksia" sect. "Banksia" because of its straight styles; and "Banksia" ser. "Salicinae" because of its cylindrical inflorescences .

"B. integrifolia"'s placement within George's taxonomic arrangement of "Banksia" may be summarised as follows::Genus "Banksia"::Subgenus "Isostylis"::Subgenus "Banksia":::Section "Oncostylis":::Section "Coccinea":::Section "Banksia"::::Series "Grandes"::::Series "Banksia"::::Series "Crocinae"::::Series "Prostratae"::::Series "Cyrtostylis"::::Series "Tetragonae"::::Series "Bauerinae"::::Series "Quercinae"::::Series "Salicinae":::::"B. dentata" - "B. aquilonia" - "B. integrifolia" - "B. plagiocarpa" - "B. oblongifolia" - "B. robur" - "B. conferta" - "B. paludosa" - "B. marginata" - "B. canei" - "B. saxicola"

21st Century

Since 1998, Austin Mast has been publishing results of ongoing cladistic analyses of DNA sequence data for the subtribe Banksiinae, which is comprised of "Banksia" and "Dryandra". His inferred phylogeny is very greatly different from George's arrangement, and provides compelling evidence for the paraphyly of "Banksia" with respect to "Dryandra".cite journal | author = Mast, A. R. | year = 1998 | title = Molecular systematics of subtribe Banksiinae ("Banksia" and "Dryandra"; Proteaceae) based on cpDNA and nrDNA sequence data: implications for taxonomy and biogeography | journal = Australian Systematic Botany | volume = 11 | pages = 321–342 | doi = 10.1071/SB97026] cite journal | author = Mast, Austin and Thomas J. Givnish | year = 2002 | title = Historical biogeography and the origin of stomatal distributions in "Banksia" and "Dryandra" (Proteaceae) based on Their cpDNA phylogeny | journal = American Journal of Botany | volume = 89 | issue = 8 | pages = 1311–1323 | id = ISSN|0002-9122 | url = http://www.amjbot.org/cgi/content/full/89/8/1311 | accessdate=2006-07-02 | doi = 10.3732/ajb.89.8.1311] cite journal | author = Mast, Austin R., Eric H. Jones and Shawn P. Havery | year = 2005 | volume = 18 | issue = 1 | title = An assessment of old and new DNA sequence evidence for the paraphyly of "Banksia" with respect to "Dryandra" (Proteaceae) | journal = Australian Systematic Botany | pages = 75–88 | publisher = CSIRO Publishing / Australian Systematic Botany Society | doi = 10.1071/SB04015] Early in 2007, Mast and Thiele initiated a rearrangement of "Banksia" by transferring "Dryandra" into it, and publishing "B." subg. "Spathulatae" for the species having spoon-shaped cotyledons. They foreshadowed publishing a full arrangement once DNA sampling of "Dryandra" was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then "B. integrifolia" is placed in "B." subg. "Spathulatae".cite journal | author = Mast, Austin R. and Kevin Thiele | year = 2007 | title = The transfer of "Dryandra" R.Br. to "Banksia" L.f. (Proteaceae) | journal = Australian Systematic Botany | volume = 20 | pages = 63–71 | doi = 10.1071/SB06016]

ubspecies and hybrids

"B. integrifolia" is a highly variable species. Some of this variation can be attributed to environmental factors, but much appears to be genetic: George writes that it "gives the impression that it is actively speciating to fill the many ecological niches through its range". Three subspecies are currently recognised: "B. i." subsp. "integrifolia", "B. i." subsp. "compar", and "B. i." subsp. "monticola". More recent work by Evans has supported this classification, with "monticola" more closely allied with the nominate subspecies than with "compar".cite journal|last=Evans|first=Katharine M.,|coauthors= Newbigin Ed, Ladiges Pauline Y.|date=2002|title=An investigation of genetic variation in Banksia integrifolia (Proteaceae) by the use of the AFLP technique.|journal=Australian Systematic Botany |publisher=CSIRO|url=http://www.publish.csiro.au/paper/SB01013.htm|issue=15|pages= 9–17]

Hybrids have been reported between "B. integrifolia" and other members of series Salicinae, specifically "B. paludosa"cite journal | last = Liber | first = C. | year = 2005 | title = "Banksia paludosa paludosa" in the Jervis Bay Area | journal = Banksia Study Group Newsletter | volume = 6 | issue = 2 | pages = 4–5 | url = http://asgap.org.au/banksSG/banksiasg-6-2.pdf | format = PDF | accessdate = 2006-10-31] cite book | author = Salkin, Alf I. | year = 1979 | title = Variation in "Banksia" in eastern Australia (thesis) | publisher = Monash University] cite journal | author = Liber, C. | year = 2004 | title = "Banksia integrifolia" × "paludosa" hybrids at Green Cape | journal = Banksia Study Group Newsletter| volume = 6 | pages = 8–9 | url = http://asgap.org.au/banksSG/banksiasg-6-1.pdf | format = PDF | accessdate = 2006-10-31] and "B. marginata",cite journal | author = Salkin, Alf I. | year = 1986 | title = Banksia cultivars | journal = Banksia Study Report | issue = 7 | pages = 17–19 | publisher = [ASGAP] | id=ISSN 0728-2893] APNI | name = "Banksia marginata" Cav. | id = 54354] but no hybrid names have been formally published to date.

References

External links

*Flora of Australia Online | name = "Banksia integrifolia" L.f. | id = 3387
*APNI | name = "Banksia integrifolia" L.f. | id = 53918