Dryandra subg. Diplophragma
Encyclopedia
Dryandra subg. Diplophragma is an obsolete subgenus within the former genus Dryandra (now Banksia ser. Dryandra). It was first published by Robert Brown
in 1830, but was discarded by George Bentham
in 1870. It was reinstated with a new circumscription by Alex George
in 1996, but was ultimately discarded again in 2007 when Austin Mast
and Kevin Thiele
sunk Dryandra into Banksia
.
. Brown's arrangement
divided Dryandra into three groups according to what Brown perceived to be variations in the number of seed separators. He allowed for these groups to be treated at subgenus or section rank, but they are now treated as having been published as sections.
D. sect. Diplophragma was defined as containing a single species, D. bipinnatifida (now Banksia bipinnatifida
), which Brown thought contained two seed separators. The epithet Diplophragma is from the Greek
diplo ("two") and phragma ("barrier"). It is not clear how Brown came to believe that this species has two seed separators, as it actually has none.
The placement and circumscription of D. sect. Diplophragma in Brown's 1830 arrangement may be summarised as follows:
published a revision of Dryandra. He retained all three of Brown's sections, but added bipinnatifid leaves (that is, leaves that are divided into lobes that are themselves divided) to the defining characters of D. sect. Diplophragma, and included in it the species D. preissii (now Banksia acuminata
), which had been published in 1845. The placement and circumscription of D. sect. Diplophragma in Meissner's arrangement
thus looks like this:
. Despite having seen only a few seeds, he correctly observed that the characters of the fruit upon which Brown based the section were not constant: Bentham also recognised that the two species placed in D. sect. Diplophragma by Meissner are not closely related; he placed D. bipinnatifida in D. sect. Aphragma, and D. preissii in D. sect. Eudryandra ser. Niveae
.
published his revision
of Dryandra in 1996, he recognised that D. bipinatifida possessed a number of very distinctive characters, especially in its fruiting structure. These include unusually large follicles and seeds; seeds that are set within the seed wings rather than along the base or one side; and unusual double wings that are attached to each side of the seed. In addition, the species has extremely long involucral bracts, and floral bracts that enlarge more than any other species. Recognising the need for this species to be placed in its own subgenus, George resurrected Diplophragma, promoting it to subgenus rank as D. subg. Diplophragma.
The placement and circumscription of D. subg. Diplophragma in George's arrangement, as amended in 1999 and 2005, may be summarised as follows:
has been publishing results of ongoing cladistic analyses of DNA sequence
data for the subtribe Banksiinae. His analyses have provided compelling evidence of the paraphyly
of Banksia
with respect to Dryandra
; that is, it seems that Dryandra arose from within the ranks of Banksia. Early in 2007, Mast and Kevin Thiele
initiated a rearrangement of Banksia by sinking Dryandra into it as B. ser. Dryandra. This transfer necessitated the setting aside of George's infrageneric arrangement of Dryandra; thus D. subg. Diplophragma is no longer current. Mast and Thiele have foreshadowed publishing a full arrangement once DNA sampling of Dryandra is complete.
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...
in 1830, but was discarded by 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 :...
in 1870. It was reinstated with a new circumscription by Alex George
Alex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...
in 1996, but was ultimately discarded again in 2007 when 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 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...
sunk Dryandra into 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...
.
According to Brown
Diplographma was first published by Brown in his 1830 Supplementum primum prodromi florae Novae HollandiaeSupplementum Primum Prodromi Florae Novae Hollandiae
Supplementum primum Prodromi florae Novae Hollandiae is an 1830 supplement to Robert Brown's Prodromus florae Novae Hollandiae et Insulae Van Diemen. It may be referred to by its standard botanical abbreviation Suppl. Prodr. Fl. Nov...
. Brown's arrangement
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...
divided Dryandra into three groups according to what Brown perceived to be variations in the number of seed separators. He allowed for these groups to be treated at subgenus or section rank, but they are now treated as having been published as sections.
D. sect. Diplophragma was defined as containing a single species, D. bipinnatifida (now Banksia bipinnatifida
Banksia bipinnatifida
Banksia bipinnatifida is a shrub endemic to Western Australia.-Description:It grows as a prostrate shrub with an underground stem and a lignotuber. It has few leaves; these are deeply lobes, and the lobes are themselves deeply lobed, giving the impression of a bipinnate leaf structure...
), which Brown thought contained two seed separators. The epithet Diplophragma is from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
diplo ("two") and phragma ("barrier"). It is not clear how Brown came to believe that this species has two seed separators, as it actually has none.
The placement and circumscription of D. sect. Diplophragma in Brown's 1830 arrangement may be summarised as follows:
- Dryandra (now B. ser. Dryandra)
- Dryandra verae (18 species)
- D. sect. Diplophragma
- D. bipinnatifida (now B. bipinnatifidaBanksia bipinnatifidaBanksia bipinnatifida is a shrub endemic to Western Australia.-Description:It grows as a prostrate shrub with an underground stem and a lignotuber. It has few leaves; these are deeply lobes, and the lobes are themselves deeply lobed, giving the impression of a bipinnate leaf structure...
)
- D. bipinnatifida (now B. bipinnatifida
- D. sect. Aphragma (4 species)
- Hemiclidia (1 species)
According to Meissner
In 1856, Carl MeissnerCarl 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...
published a revision of Dryandra. He retained all three of Brown's sections, but added bipinnatifid leaves (that is, leaves that are divided into lobes that are themselves divided) to the defining characters of D. sect. Diplophragma, and included in it the species D. preissii (now Banksia acuminata
Banksia acuminata
Banksia acuminata is a rare prostrate shrub endemic to south-west Western Australia. It was published in 1848 as Dryandra preissii, but transferred into Banksia as B. acuminata in 2007.-Description:...
), which had been published in 1845. The placement and circumscription of D. sect. Diplophragma in Meissner's arrangement
Meissner's taxonomic arrangement of Dryandra
Carl Meissner's taxonomic arrangement of Dryandra, now Banksia ser. Dryandra, was published in 1856 as part of his chapter on the Proteaceae in A. P. de Candolle's Prodromus systematis naturalis regni vegetabilis...
thus looks like this:
- Dryandra (now Banksia ser. Dryandra)
- D. sect. Eudryandra (8 series, 47 species, 7 varieties)
- D. sect. Diplophragma
- D. bipinnatifida (now B. bipinnatifidaBanksia bipinnatifidaBanksia bipinnatifida is a shrub endemic to Western Australia.-Description:It grows as a prostrate shrub with an underground stem and a lignotuber. It has few leaves; these are deeply lobes, and the lobes are themselves deeply lobed, giving the impression of a bipinnate leaf structure...
) - D. Preissii (now B. acuminataBanksia acuminataBanksia acuminata is a rare prostrate shrub endemic to south-west Western Australia. It was published in 1848 as Dryandra preissii, but transferred into Banksia as B. acuminata in 2007.-Description:...
)
- D. bipinnatifida (now B. bipinnatifida
- D. sect. Aphragma (4 species, 4 varieties)
- Hemiclidia (1 species)
According to Bentham
Along with many of Meissner's infrageneric taxa, which were overly reliant on leaf characters, Bentham discarded D. sect. Diplophragma in his 1870 arrangementBentham's taxonomic arrangement of Dryandra
George Bentham's taxonomic arrangement of Dryandra was published in 1870, in Volume 5 of Bentham's Flora Australiensis...
. Despite having seen only a few seeds, he correctly observed that the characters of the fruit upon which Brown based the section were not constant: Bentham also recognised that the two species placed in D. sect. Diplophragma by Meissner are not closely related; he placed D. bipinnatifida in D. sect. Aphragma, and D. preissii in D. sect. Eudryandra ser. Niveae
Dryandra ser. Niveae
Dryandra ser. Niveae is an obsolete series within the former genus Dryandra . It was first published by George Bentham in 1870, and was given a new circumscription by Alex George in 1996, but was ultimately discarded in 2007 when Austin Mast and Kevin Thiele sunk Dryandra into Banksia.-According to...
.
According to George
When Alex GeorgeAlex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...
published his revision
George's taxonomic arrangement of Dryandra
Alex George's taxonomic arrangement of Dryandra was the first modern-day arrangement of that taxon. First published in Nuytsia in 1996, it superseded the arrangement of George Bentham, which had stood for over a hundred years; it would later form the basis for George's 1999 treatment of Dryandra...
of Dryandra in 1996, he recognised that D. bipinatifida possessed a number of very distinctive characters, especially in its fruiting structure. These include unusually large follicles and seeds; seeds that are set within the seed wings rather than along the base or one side; and unusual double wings that are attached to each side of the seed. In addition, the species has extremely long involucral bracts, and floral bracts that enlarge more than any other species. Recognising the need for this species to be placed in its own subgenus, George resurrected Diplophragma, promoting it to subgenus rank as D. subg. Diplophragma.
The placement and circumscription of D. subg. Diplophragma in George's arrangement, as amended in 1999 and 2005, may be summarised as follows:
- Dryandra (now Banksia ser. Dryandra)
- D. ser. DryandraDryandra subg. DryandraDryandra subg. Dryandra is an obsolete series within the former genus Dryandra . It was first published at sectional rank as Dryandra verae in 1830, before being renamed Eudryandra in 1847, the replaced by the autonym at subgenus rank in 1996...
(24 series, 91 species, 39 subspecies, 23 varieties) - D. ser. HemiclidiaDryandra subg. HemiclidiaDryandra subg. Hemiclidia is an obsolete plant taxon that encompassed material that is now included in Banksia. Published at genus rank as Hemiclidia by Robert Brown in 1830, it was set aside by George Bentham in 1870, but reinstated at subgenus rank by Alex George in 1996...
(2 species) - D. subg. Diplophragma
- D. bipinnatifida (now Banksia bipinnatifidaBanksia bipinnatifidaBanksia bipinnatifida is a shrub endemic to Western Australia.-Description:It grows as a prostrate shrub with an underground stem and a lignotuber. It has few leaves; these are deeply lobes, and the lobes are themselves deeply lobed, giving the impression of a bipinnate leaf structure...
)
- D. bipinnatifida (now Banksia bipinnatifida
- D. ser. Dryandra
Recent developments
Since 1998, Austin MastAustin 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...
has been publishing results of ongoing cladistic analyses of DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
data for the subtribe Banksiinae. His analyses have provided compelling evidence of the paraphyly
Paraphyly
A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...
of 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...
with respect to Dryandra
Dryandra
Banksia ser. Dryandra is a series of 94 species of shrub to small tree in the plant genus Banksia. It was considered a separate genus named Dryandra until early 2007, when it was merged into Banksia on the basis of extensive molecular and morphological evidence that Banksia was paraphyletic with...
; that is, it seems that Dryandra arose from within the ranks of Banksia. Early in 2007, Mast and 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...
initiated a rearrangement of Banksia by sinking Dryandra into it as B. ser. Dryandra. This transfer necessitated the setting aside of George's infrageneric arrangement of Dryandra; thus D. subg. Diplophragma is no longer current. Mast and Thiele have foreshadowed publishing a full arrangement once DNA sampling of Dryandra is complete.