Banksia acuminata
Encyclopedia
Banksia acuminata is a rare prostrate shrub
Prostrate 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....

 endemic to south-west 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...

. It was published in 1848 as Dryandra preissii, but transferred 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...

as B. acuminata in 2007.

Description

It grows as a prostrate shrub with a lignotuber or underground stems. The leaves are from 7 to 15 centimetres long, on a petiole from 2 to 6 centimetres in length. They are finely divided almost back to the midrib, into narrow lobes up to 4 centimetres in length. Lobes near the leaf tip are sometimes themselves so divided.

Flowers occur in the dome-shaped head characteristic of B. ser. Dryandra. These occur at the end of branches, either alone or in clusters, and are subtended by leaves. They are orange-yellow in colour, and up to three centimetres in diameter. Each head contain from 50 to 70 flowers, arranged in a ring about a central hollow, in the manner normally associated with members of the former series Dryandra 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...

. This is surrounded by a great many involucral bracts that are narrow and taper to a long point.

As in all 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,...

, individual flowers consist of a tubular perianth
Perianth
The term perianth has two similar but separate meanings in botany:* In flowering plants, the perianth are the outer, sterile whorls of a flower...

 made up of four united tepal
Tepal
Tepals are elements of the perianth, or outer part of a flower, which include the petals or sepals. The term tepal is more often applied specifically when all segments of the perianth are of similar shape and color, or undifferentiated, which is called perigone...

s fused with the anthers, and one long wiry pistil. The pistil end is initially trapped inside the upper perianth parts, but breaks free at 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...

. In B. acuminata, the perianth is 24–25 millimetres long, pale pink at the base and mauve above, with sticky hairs on the base. The pistil is 29–40 mm long, and cream or pink in colour. The fruit is a woody follicle
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....

 firmly embedded in the woody base of the flower head, and usually containing a single winged seed.

Taxonomy

First collected by Ludwig Preiss
Ludwig Preiss
Johann August Ludwig Preiss was a German-born British botanist and zoologist.Preiss was born in Herzberg am Harz, Germany. He obtained a doctorate, probably at Hamburg, then emigrated to Western Australia...

 near the Gordon River
Gordon River (Western Australia)
The Gordon River is a river in the Great Southern of Western Australia.The headwaters of the river rise below Three Wells near Broomehill then flow in a south westerly direction parallel with the Great Southern Highway as far as Tambellup then veering westward and crossing the Albany Highway North...

 on 7 November 1840, it was published as Dryandra preissii 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 1845, in the first volume of Plantae Preissianae. Meissner did not 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 honours the collector.

When Meissner published his taxonomic arrangement of Dryandra
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...

 in 1856, he placed D. preissii with 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...

) in D. sect. Diplophragma, because the leaves of both species are twice divided. This arrangement was rejected in 1870 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 :...

, who recognised that leaf characters are largely irrelevant for the purposes of systematics
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...

. Bentham's arrangement
Bentham's taxonomic arrangement of Dryandra
George Bentham's taxonomic arrangement of Dryandra was published in 1870, in Volume 5 of Bentham's Flora Australiensis...

 was based on flower and fruit characters; noting the similarity of the flowers of other members of D. sect. Niveae, he placed D. preissii in that series. This placement was only tentative, however, as he had not been able to example any fruiting specimens.

A synonym, Josephia preissii, arises 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 1891 transfer of the genus Dryandra (now Banksia ser. Dryandra) into Josephia, on the grounds that Josephia Knight
Joseph Knight (horticulturist)
Joseph Knight , gardener to George Hibbert, was one of the first people in England to successfully propagate Proteaceae...

had priority over Dryandra R.Br.. This transfer was rejected.

In 1996, Alex George
Alex George
Alexander Segger George is a Western Australian botanist. He is the authority on the plant genera Banksia and Dryandra...

 published the first modern-day arrangement of Dryandra. He placed D. preissii alone in a new series, Dryandra ser. Acuminatae, named 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...

 acuminatus ("tapering to a protracted point") in reference to the unusual involucral bracts. The placement of D. preissii in George's arrangement of Dryandra
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...

, with 1999 and 2005 amendments, may be summarised as follows:
Dryandra (now Banksia ser. Dryandra)
D. subg. Dryandra
Dryandra subg. Dryandra
Dryandra 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...

D. ser. Floribundae
Dryandra ser. Floribundae
Dryandra ser. Floribundae 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...

 (1 species, 4 varieties)
D. ser. Armatae
Dryandra ser. Armatae
Dryandra ser. Armatae 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...

 (21 species, 7 subspecies, 4 varieties)
D. ser. Marginatae (1 species)
D. ser. Folliculosae (1 species, 5 varieties)
D. ser. Acrodontae (4 species, 2 varieties)
D. ser. Capitellatae
Dryandra ser. Capitellatae
Dryandra ser. Capitellatae is an obsolete series within the former genus Dryandra . It was published by Alex George in 1996, but discarded in 2007 when Austin Mast and Kevin Thiele sank Dryandra into Banksia.-Publication:George published the series in his 1996 "New taxa and a new infrageneric...

 (2 species, 2 subspecies)
D. ser. Ilicinae
Dryandra ser. Ilicinae
Dryandra ser. Ilicinae is an obsolete series within the former genus Dryandra . It was first published by Carl Meissner in 1856, but was discarded by George Bentham in 1870...

 (3 species, 2 varieties)
D. ser. Dryandra (3 species, 2 subspecies)
D. ser. Foliosae (3 species, 2 subspecies)
D. ser. Decurrentes (1 species)
D. ser. Tenuifoliae (2 species, 2 varieties)
D. ser. Runcinatae (4 species, 7 subspecies)
D. ser. Triangulares (3 species, 3 subspecies)
D. ser. Aphragma
Dryandra ser. Aphragma
Dryandra ser. Aphragma is an obsolete series within the former genus Dryandra . It was first published at sectional rank by Robert Brown in 1830, and was retained at that rank until 1999, when Alex George demoted it to a series...

 (9 species, 3 subspecies)
D. ser. Ionthocarpae (1 species, 2 subspecies)
D. ser. Inusitatae (1 species)
D. ser. Subulatae (1 species)
D. ser. Gymnocephalae (11 species, 4 subspecies, 2 varieties)
D. ser. Plumosae
Dryandra ser. Plumosae
Dryandra ser. Plumosae is an obsolete series within the former genus Dryandra . It was published by Alex George in 1996, but discarded in 2007 when Austin Mast and Kevin Thiele sank Dryandra into Banksia....

 (3 species, 2 subspecies)
D. ser. Concinnae (3 species)
D. ser. Obvallatae (7 species, 2 varieties)
D. ser. Pectinatae (1 species)
D. ser. Acuminatae
D. preissii (now Banksia acuminata)
D. 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...

D. subg. Hemiclidia
Dryandra subg. Hemiclidia
Dryandra 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
Dryandra subg. Diplophragma
Dryandra subg. Diplophragma is an obsolete subgenus within the former genus Dryandra . It was first published by Robert Brown in 1830, but was discarded by George Bentham in 1870...

 (1 species)


George's arrangement remained current until February 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...

 transferred Dryandra into Banksia. As the name Banksia preissii had already been published by 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...

 for the plant now known as Pimelea preissii, Mast and Thiele were forced to choose a new specific epithet; their choice, "acuminata", was for the same reasons as George's D. ser. Acuminatae.

Mast and Thiele also published B. subg. Spathulatae
Banksia subg. Spathulatae
Banksia subg. Spathulatae is a valid botanic name for a subgenus of Banksia. It was published in 2007 by Austin Mast and Kevin Thiele, and defined as containing all those Banksia species having spathulate cotyledons...

 for the Banksia taxa having spoon-shaped cotyledon
Cotyledon
A cotyledon , is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon may become the embryonic first leaves of a seedling. The number of cotyledons present is one characteristic used by botanists to classify the flowering plants...

s, thus redefining 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...

 as comprising those that do not. They were not ready, however, to tender an infrageneric arrangement encompassing Dryandra, so as an interim measure they transferred Dryandra into Banksia at series
Series (botany)
Series is a low-level taxonomic rank below that of section but above that of species.In botany, a series is a subdivision of a genus...

 rank. This minimised the nomenclatural disruption of the transfer, but also caused George's rich infrageneric arrangement to be set aside. Thus under the interim arrangements implemented by Mast and Thiele, B. acuminata is placed in 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...

, ser. Dryandra.

Distribution and habitat

It is restricted to the Jarrah Forest
Jarrah Forest
Jarrah Forest is an Interim Biogeographic Regionalisation for Australia region in Western Australia.-Location and description:The ecoregion stands on the 300m high Yilgarn block inland plateau and includes wooded valleys such as those of Western Australia's Murray River and the Helena River near...

 and Avon Wheatbelt
Avon Wheatbelt
Avon Wheatbelt is an Interim Biogeographic Regionalisation for Australia region in Western Australia and part of the larger Southwest Australia savanna ecoregion.-Further reading:...

 regions 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...

, occurring between Woodanilling, Cranbrook
Cranbrook, Western Australia
Cranbrook is a small town in the Great Southern region of Western Australia between Katanning, Kojonup and Mount Barker, situated 320km south of Perth. It is billed as "The Gateway to the Stirlings", referring to the nearby Stirling Range National Park...

 and Collie
Collie, Western Australia
-External links:*...

. It grows in lateritic soils amongst Eucalyptus
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...

woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...

, and also in sand in kwongan
Kwongan
Kwongan is a type of heathland found on the coastal plains of Western Australia. The name is derived from the language of the Noongar people. Kwongan comprises floristically-rich heath with dense thickets of sclerophyllous shrubs and isolated small trees...

.

Conservation status

As of 2008, B. acuminata is listed as "Priority Four - Rare" on the Department of Environment and Conservation's Declared Rare and Priority Flora List. This means that the species is considered to be rare, but there do not appear to be any serious threats to its survival.

An assessment of the potential impact of climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

on this species found that it was likely to be driven to extinction by loss of habitat by 2080, even under mild climate change scenarios.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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