Brown's taxonomic arrangement of Dryandra

Robert Brown's taxonomic arrangement of "Dryandra" was the first arrangement of what is now "Banksia" ser. "Dryandra". His initial arrangement was published in 1810, and a further arrangement, including an infrageneric classification, followed in 1830. Aspects of Brown's arrangements can be recognised in the later arrangements of George Bentham and Alex George.

Background

The dryandras are a group of proteaceous shrubs endemic to southwest Western Australia. For nearly two hundred years they were considered a separate genus, having been published at that rank in 1810 by Robert Brown. In 2007 they were transferred into the genus "Banksia" as "B." ser. "Dryandra". There are now nearly 100 species, plus numerous subspecies and varieties.

Brown's 1810 arrangement

The genus "Dryandra" was first published by Brown in "On the natural order of plants called Proteaceae", which was read to the Linnean Society of London in 1809, and published the following year in Volume X of Transactions of the Linnean Society of London. Brown listed 13 species, but did not attempt an infrageneric classification of them. Later that year, he republished his descriptions of "Dryandra" in his "Prodromus Florae Novae Hollandiae et Insulae Van Diemen".cite book | last = Brown | first = Robert | authorlink = Robert Brown (botanist) | year = 1810 | title = Prodromus Florae Novae Hollandiae et Insulae Van Diemen | pages = 106–107 | location = London | publisher = Taylor]

Brown's 1810 arrangement was as follows::Genus "Dryandra" (now "B." ser. "Dryandra")::"D. floribunda" (now "B. sessilis")::"D. cuneata" (now "B. obovata")::"D. armata" (now "B. armata")::"D. falcata" (now "B. falcata")::"D. formosa" (now "B. formosa")::"D. mucronulata" (now "B. mucronulata")::"D. plumosa" (now "B. plumosa")::"D. obtusa" (now "B. obtusa")::"D. nivea" (now "B. nivea")::"D. longifolia" (now "B. prolata")::"D. tenuifolia" (now "B. tenuis")::"D. pteridifolia" (now "B. pteridifolia")::"D. blechnifolia" (now "B. pellaeifolia")

Brown's 1830 arrangement

Twenty years later, Brown issued a supplement to his "Prodromus", entitled "Supplementum Primum Prodromi Florae Novae Hollandiae". He added a further 11 species to "Dryandra", but transferred "D. falcata" into a new, monospecific genus as "Hemiclidia Baxteri", on the grounds that its follicles always contained only a single seed. The remaining 23 "Dryandra" species were divided into three sections based on the number of seed separators in each follicle. He allowed for these groups to be given subgenus rather than sectional rank,cite book | author = Brown, Robert | year = 1830 | title = Supplementum Primum Prodromi Florae Novae Hollandiae | publisher = Taylor | location = London] but they are now treated as having been published as sections.e.g. APNI | name = "Dryandra" sect. "Diplophragma" R.Br. | id = 25117]

The first section was defined as containing those species with a single seed separator. This accounted for the majority of species, and was named "Dryandra verae" ("True Dryandra"). "D." sect. "Diplophragma", was a monotypic section containing "D. bipinnatifida" (now "B. bipinnatifida"), the follicles of which Brown thought contained two separators. Finally, "D." sect. "Aphragmia" was defined as containing two species that Brown thought lacked a seed separator altogether.

Brown's 1830 arrangement may be summarised as follows::Genus "Dryandra"::"Dryandra verae":::"D. floribunda" (now "B. sessilis"):::"D. cuneata" (now "B. obovata"):::"D. armata" (now "B. armata"):::"D. Serra" (now "B. serra"):::"D. concinna" (now "B. concinna"):::"D. foliolata" (now "B. foliolata"):::"D. squarrosa" (now "B. squarrosa"):::"D. formosa" (now "B. formosa"):::"D. mucronulata" (now "B. mucronulata"):::"D. Baxteri" (now "B. biterax"):::"D. plumosa" (now "B. plumosa"):::"D. obtusa" (now "B. obtusa"):::"D. arctotidis" (now "B. arctotidis"):::"D. nivea" (now "B. nivea"):::"D. Fraseri" (now "B. fraseri"):::"D. longifolia" (now "B. prolata"):::"D. seneciifolia" (now "B. seneciifolia"):::"D. tenuifolia" (now "B. tenuis")::Section "Diplophragma":::"D. bipinnatifida" (now "B. bipinnatifida")::Section "Aphragma":::"D. nervosa" (now "B. alliacea"):::"D. callophylla" (now "B. calophylla"):::"D. pteridifolia" (now "B. pteridifolia"):::"D. blechnifolia" (now "B. pellaeifolia"):Genus "Hemiclidia":::"H. Baxteri" (now "B. falcata")

Legacy

Brown's arrangement remained current until 1856, when Carl Meissner published his arrangement. In the interim a number of new species were published, notably in John Lindley's 1839 "A Sketch of the Vegetation of the Swan River Colony", and by Meissner in J. G. C. Lehmann's 1845 "Plantae Preissianae". However, the only significant change to Brown's classification was Stephan Endlicher's 1847 publication of "Eudryandra" as a replacement name for Brown's "Dryandra verae".cite book | first = Stephan | last = Endlicher | authorlink = Stephan Endlicher | year = 1847 | title = Genera Plantarum Secundum Ordines Naturales Disposita Supplement 4 | pages = [http://www.botanicus.org/page/503709 88] ]

Meissner's 1856 arrangement maintained Brown's distinction between "Dryandra" and "Hemiclidia", and his three "Dryandra" sections, but further divided "Eudryandra" into eight series.cite encyclopedia | editor = de Candolle, A. P. | year = 1856 | encyclopedia = Prodromus systematis naturalis regni vegetabilis | volume = XIV | author = Meissner, Carl | title = XLIV. Dryandra | pages = 467–481 | location = Paris | publisher = Sumptibus Sociorum Treuttel et Wurtz] cite encyclopedia | editor = de Candolle, A. P. | year = 1856 | encyclopedia = Prodromus systematis naturalis regni vegetabilis | volume = XIV | author = Meissner, Carl | title = XLV. Hemiclidia | pages = 481–482 | location = Paris | publisher = Sumptibus Sociorum Treuttel et Wurtz] George Bentham abandoned "Hemiclidia" in his 1870 arrangement, placing "D. falcata" within "D." ser. "Armatae" because quote|"as far as I can understand the characters given, the difference in the fruit upon which the genus "Hemiclidia" was founded is merely the result of the abortion of one ovule, which occurs occasionally or perhaps constantly in one or two other species of "Dryandra"."cite encyclopedia | author = Bentham, George | year = 1870 | title = Dryandra | encyclopedia = Flora Australiensis | volume = Volume 5: Myoporineae to Proteaceae | pages = 562–584 | location = London | publisher = L. Reeve & Co.] . He also discarded "D." sect. "Diplophragma", placing "B. bipinnatifida" in section "Aphragma", on the grounds that quote|"in the few seeds that I have been able to examine, the separation of the integument from the nucleus when not consolidated with the corresponding integument of the other seed has not appeared to me to be at all constant." Thus of Brown's names, only "Aphragma" was still accepted.

In 1996, Alex George published a new arrangement. He revived the names "Hemiclidia" and "Diplophragma", but with somewhat different circumscriptions. Both were given subgeneric rank, and "Eudryandra" was replaced by the autonymic subgenus "D." subg. "Dryandra". "Aphragma" was retained, but demoted to series rank within subgenus "Dryandra".cite encyclopedia | last = George | first = Alex S. | authorlink = Alex George | year = 1999 | title = "Dryandra" | editor = Wilson, Annette (ed.) | encyclopedia = Flora of Australia | volume = 17B: Proteaceae 3: Hakea to Dryandra | pages = 251–363 | location = Collingwood, Victoria | publisher = CSIRO Publishing / Australian Biological Resources Study | id = ISBN 0-643-06454-0] This arrangement was current until early 2007, when Austin Mast and Kevin Thiele transferred the entire "Dryandra" genus into "Banksia" on the grounds that "Banksia" was paraphyletic with respect to "Dryandra". As Mast and Thiele were not yet ready to propose an infrageneric classification for their new circumscription of "Banksia", they transferred "Dryandra" into "Banksia" at series rank, so as to cause minimal disruption to the current arrangement of "Banksia". Thus the rich infrageneric classification of "Dryandra", including all of Brown's taxa, has been set aside, at least temporarily.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

ee also

* Brown's taxonomic arrangement of "Banksia"
* Meissner's taxonomic arrangement of "Banksia"
* Meissner's taxonomic arrangement of "Dryandra"
* Bentham's taxonomic arrangement of "Banksia"
* Bentham's taxonomic arrangement of "Dryandra"
* George's taxonomic arrangement of "Banksia"
* George's taxonomic arrangement of "Dryandra"
* Thiele and Ladiges' taxonomic arrangement of "Banksia"