Brown'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". It was the first survey of "Banksia" species to be published, and included descriptions of a number of previously undescribed species.cite book | author = Brown, Robert | year = 1810 | title = Prodromus Florae Novae Hollandiae et Insulae Van Diemen | publisher = Taylor | location = London] cite book | author = Brown, Robert | year = 1830 | title = Supplementum Primum Prodromi Florae Novae Hollandiae | publisher = Taylor | location = London]

Background

"Banksia" is a genus of around 175 species in the plant family Proteaceae. An iconic Australian wildflower and popular garden plant, they are recognised by their flower spikes or domes, and their fruiting "cones". They grow in forms varying from prostrate woody shrubs to trees up to 35 metres tall, and occur in all but the most arid areas of Australia. As heavy producers of nectar, they are important sources of food for nectariferous animals such as honeyeaters and honey possum, and they are of economic importance to the nursery and cut flower industries. However they are seriously threatened by a number of processes including land clearing, frequent burning, and disease, and a number of species are rare and endangered.

Brown's 1810 arrangement

Specimens of "Banksia" were first collected by Sir Joseph Banks and Dr Daniel Solander, naturalists on HM Bark "Endeavour" during Lieutenant (later Captain) James Cook's 1770 voyage to the Pacific Ocean. By the time of Brown's 1810 arrangement, less than 20 "Banksia" species had been published. However, Brown had himself collected specimens of 26 unpublished species in 1801 and 1802. 13 of these were thought by Brown to belong to a new genus, which he named "Dryandra" (now "B." ser. "Dryandra"). The remaining species were assigned to "Banksia"; thus Brown was able to publish an arrangement of 31 species.

Brown divided "Banksia" into two unranked groups. He placed "B. ilicifolia" alone in "Isostylis" because of its unusual dome-shaped inflorescences. All other species were placed in "Banksia verae", the "true banksias", because they have the elongate flower spike then considered characteristic of "Banksia". The arrangement was as follows::"Banksia"::"Banksia verae":::"B. pulchella":::"B. sphærocarpa":::"B. nutans":::"B. ericifolia":::"B. spinulosa":::"B. collina" (now "B. spinulosa" var. "collina"):::"B. occidentalis":::"B. littoralis":::"B. marginata":::"B. depressa" (now "B. marginata"):::"B. patula" (now "B. marginata"):::"B. australis" (now "B. marginata"):::"B. insularis" (now "B. marginata"):::"B. integrifolia":::"B. compar" (now "B. integrifolia" subsp. "compar"):::"B. verticillata":::"B. coccinea":::"B. paludosa":::"B. oblongifolia":::"B. latifolia" (now "B. robur"):::"B. marcescens" (now "B. praemorsa"):::"B. attenuata":::"B. elatior" (now "B. aemula"):::"B. serrata":::"B. æmula":::"B. dentata":::"B. quercifolia":::"B. speciosa":::"B. grandis":::"B. repens"::"Isostylis":::"B. ilicifolia"

Brown's 1830 arrangement

Brown released a second edition of his "Prodromus" in 1821, but no new species of "Banksia" had been collected since that time, so the arrangement was the same as in the first edition. Between 1823 and 1829, a number of new species were collected, most of which were not published. In 1830, Brown issued his "Supplementum", describing eleven additional "Banksia" species, nine of which were previously unpublished. A revised arrangement was not proffered; instead, Brown gave a position into which each new taxon was to be inserted in the 1810 arrangement. Brown's 1830 arrangement may be summarised as follows::"Banksia"::"Banksia verae":::"B. pulchella":::"B. sphærocarpa":::"B. nutans":::"B. ericifolia":::"B. spinulosa":::"B. Cunninghamii" (now "B. spinulosa" var. "cunninghamii"):::"B. collina" (now "B. spinulosa" var. "collina"):::"B. occidentalis":::"B. littoralis":::"B. marginata":::"B. depressa" (now "B. marginata"):::"B. patula" (now "B. marginata"):::"B. australis" (now "B. marginata"):::"B. insularis" (now "B. marginata"):::"B. integrifolia":::"B. compar" (now "B. integrifolia" subsp. "compar"):::"B. verticillata":::"B. coccinea":::"B. paludosa":::"B. oblongifolia":::"B. latifolia" (now "B. robur"):::"B. marcescens" (now "B. praemorsa"):::"B. media":::"B. attenuata":::"B. Caleyi":::"B. Baueri":::"B. Menziesii":::"B. elatior" (now "B. aemula"):::"B. serrata":::"B. æmula":::"B. dentata":::"B. quercifolia":::"B. speciosa":::"B. Solandri":::"B. grandis":::"B. Baxteri":::"B. Goodii":::"B. prostrata" (now "B. gardneri"):::"B. repens":::"B. Dryandroides":::"B. Brownii"::"B." subg. "Isostylis":::"B. ilicifolia"

Legacy

Brown's "Banksia verae" was renamed "Eubanksia" by Stephan Endlicher in 1847. The arrangement was eventually superseded by Carl Meissner's 1856 revision. Meissner retained "Eubanksia" and "Isostylis", giving them sectional rank. They have since been promoted to subgenus rank by Alex George, although "Eubanksia" is now known as "B." subg. "Banksia".The genus Banksia L.f. (Proteaceae)] cite encyclopedia | author = George, Alex S. | year = 1999 | title = "Banksia" | editor = Wilson, Annette | encyclopedia = Flora of Australia | volume = Volume 17B: Proteaceae 3: Hakea to Dryandra | pages = 175–251 | publisher = CSIRO Publishing / Australian Biological Resources Study | id = ISBN 0-643-06454-0]

Recent cladistic analyses have revealed a phylogeny that Brown's arrangement fails to reflect. "Dryandra" is shown to have arisen from within the ranks of "Banksia", so should not have been treated as a separate genus; and "B. ilicifolia" is a fairly derived species, contrary to the basal position suggested by Brown. The phyletic order of species is accurate in some cases but grossly inaccurate in others; for example "B. brownii" and "B. nutans" are closely related but are placed very far apart by Brown.cite journal | author = Mast, Austin 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 R. 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] 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]

References