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Banksia aemula

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Vorlage:Italic title

Systematik

Banksia aemula, commonly known as the wallum banksia, is a lignotuberous shrub of the Proteaceae family. Found from Bundaberg south down to Sydney on the Australian east coast, it is encountered as a shrub found in coastal heath on deep sandy soil, known as Wallum, or taller tree to 8 m (25 ft). It has wrinkled orange bark and shiny green serrated leaves, with green-yellow flower spikes, known as inflorescences, appearing in autumn. The flower spikes turn grey as they age and large grey follicles appear. Banksia aemula resprouts from its woody lignotuber after bushfires.

First described by the botanist Robert Brown in the early 19th century, it derives its specific named 'similar' from its resemblance to the closely related Banksia serrata. No separate varieties of are recognised. It was known for many years in New South Wales as Banksia serratifolia, however the name, originally coined by Richard Anthony Salisbury, proved invalid. Banksia aemula is pollinated by, and provides food for, a wide array of mammals, birds, and invertebrates; honeyeaters are particularly prominent visitors. Grown as a garden plant, it is less commonly seen in horticulture than its close relative B. serrata.

Description

Banksia aemula, showing large follicles, Cranbourne Annexe, RBG Melbourne Oct 2003

Banksia aemula is generally a gnarled shrub or small tree to 8 m (25 ft) although usually smaller. The trunk has thick orange-brown wrinkled and warty bark, and the new growth is hairy but becoming smooth.[1] New shoot growth is in spring and summer.[2] The shiny green leaves are obovate to oblong in shape and measure 3–22 cm (1.4–9 in) in length, and 1–2 cm (0.4-0.8 in) wide. The leaf ends are truncate and the margins flat and serrated. Flowering is in autumn, from March to June; the green-yellow flower spikes, known as inflorescences, are terminal, found on the ends of branches and emerging from the foliage. Measuring 4 to 20 cm (1.6–8 in) in height and 8 to 9 cm (2.8-3.2 in) in width, they are various shades of pale and greenish yellow.[1] Anywhere from 800 to 1700 individual small flowers arise from a central woody spike (or rachis). Initially tipped with white conical pollen presenters, the flowers open sequentially from the bottom to the top of the inflorescence over one to two weeks,[3] in a process known as anthesis. Each flower produces nectar for a around seven days after opening.[4] The flower spikes turn grey as they age and up to 25 finely furred grey follicles appear, which can be very large, measuring 3–4.5 cm (1.2-2.6 in) long, 2–3.5 cm (0.8-1.4 in) high, and 2–3.5 cm (0.8-1.4 in) wide. They split open either after bushfire or spontaneously, and release oval seeds 4-4.7 cm (1.6-1.9 in) in length, composed of a wedge-shaped body 1–1.5 cm long and1.1–1.6 cm wide, and curved wing 2–3.2 cm (0.8-1.3 in) wide. Banksia aemula resprouts from its woody lignotuber after fire.[1]

Banksia aemula closely resembles Banksia serrata but the latter can be distinguished by a greyer, not orange-brown, trunk, and adult leaves wider than 2 cm in diameter. Inflorescences of serrata are generally a duller grey-yellow in colour, and have more fusiform (spindle-shaped) or cylindrical pollen presenters tipping unopened flowers.[5] Finally the follicles are smaller.

Taxonomy

inflorescence in late bud, showing more conical pollen presenters on the tips of the styles

Banksia aemula was collected by Scottish botanist Robert Brown in June 1801 in the vicinity of Port Jackson, and published by him in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen. The specific name , Latin for 'similar', refers to its similarity to B. serrata.[6] Brown also collected a taller tree-like specimen from Sandy Cape which he called Banksia elatior, the specific name derived from the Latin adjective ēlātus "elevated".[7]

The Kabi people of the Sunshine Coast called it wallum, giving rise not only to its common name of wallum banksia but also the ecological community it grows in.[8] Banyalla is another aboriginal name for the species.[6]

History

Richard Anthony Salisbury published Banksia serratifolia in 1796 which was followed by Otto Kuntze, and then Karel Domin in 1921, and subsequently used in New South Wales until Alex George's 1981 revision of the genus, when he conclusively established aemula as the correct name to be used. He pointed out that Salisbury's original described the leaves only, and hence was insufficient to diagnose the species and is a nomen dubium—the description could have fit juvenile leaves of B. paludosa as well. In fact, Brown himself had been unsure whether serratifolia applied to what he called Banksia aemula. Salisbury's taxon appeared as Banksia serraefolia in Knight's 1809 work On the cultivation of the plants belonging to the natural order of Proteeae, but that entry possibly refers to serrata.[1]

Under Brown's taxonomic arrangement, B. aemula and B. elatior were placed in subgenus Banksia verae, the "True Banksias", because the inflorescence is a typical Banksia flower spike. Banksia verae was renamed Eubanksia by Stephan Endlicher in 1847, and demoted to sectional rank by Carl Meissner in his 1856 classification. Meissner further divided Eubanksia into four series, with B. aemula placed in series Quercinae on the basis of its toothed leaves.[9] When George Bentham published his 1870 arrangement in Flora Australiensis, he discarded Meissner's series, replacing them with four sections. B. menziesii was placed in Orthostylis, a somewhat heterogeneous section containing 18 species.[10] This arrangement would stand for over a century.

In 1891, German botanist Otto Kuntze challenged the generic name Banksia L.f., on the grounds that the name Banksia had previously been published in 1775 as Banksia J.R.Forst & G.Forst, referring to the genus now known as Pimelea. Kuntze proposed Sirmuellera as an alternative, republishing B. aemula as "Sirmuellera serratifolia". The challenge failed, Banksia L.f. was formally conserved, and Sirmuellera serratifolia (Salisb.) Kuntze is now a nomenclatural synonym of B. aemula.[1]

Current placement

Alex George published a new taxonomic arrangement of Banksia in his classic 1981 monograph The genus Banksia L.f. (Proteaceae).[1] Endlicher's Eubanksia became B. subg. Banksia, and was divided into three sections. B. aemula was placed in B. sect. Banksia, and this was further divided into nine series, with B. aemula placed in B. ser. Banksia. He thought its closest relative was clearly Banksia serrata and then B. ornata, and that the three formed a link with western species. Since Brown's original publication had treated all of Fraser's specimens as syntypes for the species, George also chose a lectotype.[1]

In 1996, Kevin Thiele and Pauline Ladiges published a new arrangement for the genus, after cladistic analyses yielded a cladogram significantly different from George's arrangement. Thiele and Ladiges' arrangement retained B. aemula in series Banksia, placing it in B. subser. Banksia along with serrata as its sister taxon (united by their unusual seedling leaves) and ornata as next closest relative.[11] This arrangement stood until 1999, when George effectively reverted to his 1981 arrangement in his monograph for the Flora of Australia series.[12]

Inflorescence after anthesis, with all flowers fully opened

Under George's taxonomic arrangement of Banksia, B. aemula's taxonomic placement may be summarised as follows:

Genus Banksia
Subgenus Banksia
Section Banksia
Series Banksia
B. serrata
B. aemula
B. ornata
B. baxteri
B. speciosa
B. menziesii
B. candolleana
B. sceptrum

In 2002, a molecular study by Austin Mast again showed the three eastern species to form a group, but they were only distantly related to other members of the series Banksia. Instead, they formed a sister group to a large group comprising the series Prostratae, Ochraceae, Tetragonae (including Banksia elderiana), Banksia lullfitzii and Banksia baueri.[13]

In 2005, Mast, Eric Jones and Shawn Havery published the results of their cladistic analyses of DNA sequence data for Banksia. They inferred a phylogeny greatly different from the accepted taxonomic arrangement, including finding Banksia to be paraphyletic with respect to Dryandra.[14] A new taxonomic arrangement was not published at the time, but early in 2007 Mast and Thiele initiated a rearrangement by transferring Dryandra to Banksia, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons; in this way they also redefined the autonym B. subg. Banksia. 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. aemula is placed in B. subg. Banksia.[15]

Distribution and habitat

Banksia aemula is found along the east coast of Australia from around 70 km (45 mi) north of Bundaberg in central Queensland down to Sydney.[2] Specifically, its southernmost occurrence is at La Perouse on the northern side of Botany Bay.[16] It is also found on Fraser, Moreton and North Stradbroke Islands. Almost all populations are within a few km of the coast, except for one at Agnes Banks in western Sydney, and two just north and south of Grafton at Coaldale and Glenreagh, and a last around 30 km (19 mi) southwest of Bundaberg.[2]

It is most commonly found in deep sandy soils, either on dunes or flattish areas which may be seasonally wet. In Queensland it is found with Banksia robur, with the latter species found in flatter wetter areas and aemula found on rises. It is also found with Banksia oblongifolia in Queensland.[2] These areas, with open woodland or heathland, are known as wallum.[6] It is a component of the Eastern Suburbs Banksia Scrub (ESBS), designated an endangered ecological community.[17] On the New South Wales Central Coast, it grows as a 1-2 m (3-7 ft) high shrub and is a canopy component of Banksia aemula open heathland, located on coastal headlands on highly leached Pleistocene white sands overlying Triassic and Permian strata. Areas include Wybung Head in Munmorah State Conservation Area, and near Myall Lakes. Other plants it grows in association with include Ricinocarpos pinifolius, Brachyloma daphnoides, Dillwynia glaberrima, D. retorta, Allocasuarina distyla, Bossiaea ensata, Aotus ericoides, Phyllota phylicoides, and Empodisma minus. Sandmining has eradicated much of the community around Redhead. In less leached yellower sands, the community (and B. aemula) is replaced by a taller heath containing B. serrata and B. oblongifolia.[18] A study of coastal heaths on Pleistocene sand dunes around the Myall Lakes found B. aemula grew on ridges (dry heath) and B. oblongifolia on slopes (wet heath), and the two species did not overlap.[19] Manipulation of seedlings in the same study area showed that B. aemula grows longer roots seeking water and that seedlings do grow in wet heath, but it is as yet unclear why the species does not grow in wet heath as well as dry heath.[20] Unlike similar situations with banksia species in Western Australia, the two species did not appear to impact negatively on each other.[21]

The Agnes Banks Woodland in western Sydney has been recognised by the New South Wales Government as an Endangered Ecological Community. Here Banksia aemula is an understory plant in low open woodland, with scribbly gum (Eucalyptus sclerophylla), narrow-leaved apple (Angophora bakeri) and B. serrata as canopy trees, and B. oblongifolia, Conospermum taxifolium, Ricinocarpus pinifolius, Dillwynia sericea and nodding geebung (Persoonia nutans) as other understory species.[22]

Ecology

Vorlage:Seealso Most Proteaceae and all Banksia species, including B. scabrella, have proteoid roots, roots with dense clusters of short lateral rootlets that form a mat in the soil just below the leaf litter. These roots are particularly efficient at absorbing nutrients from nutrient-poor soils, such as the phosphorus-deficient native soils of Australia.[23] A study of six wallum species, including B. aemula, found they have adapted to very low levels of phosphorus and are highly sensitive to increased levels of the element, leading to phosphorus toxicity. Some evidence suggests they are efficient at using potassium, and sensitive to calcium toxicity as well.[24]

A 1998 study in Bundjalung National Park in Northern New South Wales found that B. aemula inflorescences are foraged by a variety of small mammals, including marsupials such as Yellow-footed Antechinus (Antechinus flavipes), and rodents such as Pale Field Rat (Rattus tunneyi), Australian Swamp Rat (R. lutreolus) and Grassland Melomys (Melomys burtoni) and even the House mouse (Mus musculus). These animals carry pollen loads comparable to those of nectarivorous birds, making them effective pollinators. Grey-headed Flying Foxes (Pteropus poliocephalus) were also observed visiting B. aemula and their heads and bellies were noted to contact stigmas while feeding.[25] Bird species that have been observed feeding at the flowers of B. aemula include Rainbow Lorikeet, Scarlet,[26] and Lewin's Honeyeaters.[3] Several other honeyeaters were recorded for the Banksia Atlas including the New Holland, Brown, White-cheeked, and Tawny-crowned Honeyeaters, Noisy Miner, Little Wattlebird and Noisy Friarbird.[2] The Bundjalung field study found the Brown Honeyeater carried much higher loads of B. aemula pollen than other species measured, which included White-cheeked and Yellow-faced Honeyeaters and Silvereyes.[25] Insects such as ants and bees (including the introduced honeybee) have also been recorded.[2]

It resprouts from a lignotuber or shoots from epicormic buds after fire.[2] Fire management of Banksia aemula heath in Southeast Queensland recommend 7 to 20 year fire intervals.[27] Intervals of 10-15 years are recommended for the Eastern Suburbs Banksia Scrub, as longer leads to overgrowth by Leptospermum laevigatum.[28]

Cultivation

Plate from Curtis's Botanical Magazine, drawn by William J. Hooker, 1826

Banksia aemula was one of the first banksias to be cultivated in England in 1788,[6] where it was illustrated in Curtis's Botanical Magazine and the rival The Botanical Register.[29] Its shiny green leaves, showy flower spikes, huge follicles and wrinkled bark are attractive horticultural features.[29] It is also a bird and insect-attracting plant.[30]

In cultivation, although relatively resistant to dieback, it does require a well drained slightly acid (pH 5.5-6.5) soil,[29] preferably fairly sandy and a sunny aspect. Summer watering is also prudent, as it does not suffer water stress well.[6] Slow growing,[31] the plant takes four to six years to flower from seed.[29] It is less commonly grown than Banksia serrata.[5]

It has also been used as a rootstock for grafting Banksia speciosa, and has potential in bonsai.[29]

Although Banksia attenuata was the common banksia in Australian children's author May Gibbs' own childhood in Western Australia, the old flower spikes of Banksia aemula with their large follicles are thought to have been the inspiration for her Big Bad Banksia Men.[31]


References

Wikispecies: Banksi aemula – Artenverzeichnis

Vorlage:Wikisourcepar Vorlage:Wikisourcepar Vorlage:Wikisourcepar Vorlage:Wikisourcepar Vorlage:Reflist

  1. ↑ a b c d e f g Vorlage:The genus Banksia L.f. (Proteaceae)
  2. ↑ a b c d e f g Vorlage:The Banksia Atlas pp. 50-51.
  3. ↑ a b Elizabeth Dalgleish: Effectiveness of Invertebrate and Vertebrate Pollinators and the Influence of Pollen Limitation and Inflorescence Position on Follicle Production of Banksia aemula (Family Proteaceae). In: Australian Journal of Botany. 47. Jahrgang, 1999, S. 553–62.
  4. ↑ Copland BJ, Whelan RJ: Seasonal Variation in Flowering Intensity and Pollination Limitation of Fruit Set in Four Co-Occurring Banksia Species. In: Journal of Ecology. 77. Jahrgang, Nr. 2, 1989, S. 509–23.
  5. ↑ a b Brian Walters: Banksia aemula. In: Australian Native Plants Society website. Australian Native Plants Society, November 2007, abgerufen am 4. Juni 2010.
  6. ↑ a b c d e John Wrigley, Fagg, Murray: Banksias, Waratahs and Grevilleas. Angus & Robertson, Sydney 1991, ISBN 0-207-17277-3, S. 87.
  7. ↑ Simpson DP: Cassell's Latin Dictionary. 5. Auflage. Cassell Ltd., London 1979, ISBN 0-304-52257-0, S. 208.
  8. ↑ Margaret Somerville: Wildflowering: The life and places of Kathleen McArthur. University of Queensland Press, St Lucia, Queensland 2004, ISBN 0-7022-3450-8, S. 11.
  9. ↑ Meissner, Carl: Prodromus systematis naturalis regni vegetabilis, pars decima quarta. Hrsg.: A. P. de Candolle. Sumptibus Victoris Masson, Paris 1856, Proteaceae (Latein).
  10. ↑ Vorlage:Cite encyclopedia
  11. ↑ Thiele, Kevin; Ladiges, Pauline Y.: A cladistic analysis of Banksia (Proteaceae). In: Australian Systematic Botany. 9. Jahrgang, Nr. 5, 1996, S. 661–733, doi:10.1071/SB9960661.
  12. ↑ Vorlage:Cite encyclopedia
  13. ↑ Austin R. Mast, Givnish, Thomas J.: Historical biogeography and the origin of stomatal distributions in Banksia and Dryandra (Proteaceae) based on their cpDNA phylogeny. In: American Journal of Botany. 89. Jahrgang, Nr. 8, August 2002, ISSN 0002-9122, S. 1311–23, doi:10.3732/ajb.89.8.1311 (amjbot.org [abgerufen am 2. Juli 2006]).
  14. ↑ Mast, Austin R.; Jones, Eric H.; Havery, Shawn P.: An assessment of old and new DNA sequence evidence for the paraphyly of Banksia with respect to Dryandra (Proteaceae). In: Australian Systematic Botany. 18. Jahrgang, Nr. 1. CSIRO Publishing / Australian Systematic Botany Society, 2005, S. 75–88, doi:10.1071/SB04015.
  15. ↑ Mast, Austin R.; Thiele, Kevin: The transfer of Dryandra R.Br. to Banksia L.f. (Proteaceae). In: Australian Systematic Botany. 20. Jahrgang, 2007, S. 63–71, doi:10.1071/SB06016.
  16. ↑ Fairley A, Moore P: Native Plants of the Sydney District:An Identification Guide. 2nd Auflage. Kangaroo Press, Kenthurst, NSW 2000, ISBN 0-7318-1031-7, S. 176.
  17. ↑ Threatened Species Unit, Metropolitan Region, Environment Protection and Regulation Division, Department of Environment and Conservation,: Eastern Suburbs Banksia Scrub in the Sydney Basin Bioregion. In: Department of Environment, Climate Change and Water website. Natinal Parks and Wildlife Service, New South Wales Government, 29. Oktober 2003, abgerufen am 6. Juni 2010.
  18. ↑ Doug Benson: The Vegetation of the Gosford and Lake Macquarie 1:100 000 Vegetation Map Sheet. In: Cunninghamia. 1. Jahrgang, Nr. 4, 1986, S. 467–89 (http://www.rbgsyd.nsw.gov.au/__data/assets/pdf_file/0003/97635/Benson_1c.pdf (fulltext) [PDF]).
  19. ↑ Myerscough, Peter J.; Clarke Peter J.; Skelton Nicholas J.: Plant coexistence in coastal heaths: Floristic Patterns and Species Attributes. In: Australian Journal of Ecology. 20. Jahrgang, 1995, S. 482–93 (http://www.une.edu.au/ers/staff-profile-doc-folders/peter-clarke/1995-myerscough-et-al-aust-j-ecology.pdf (fulltext) [PDF]).
  20. ↑ Myerscough, Peter J.; Clarke Peter J.; Skelton Nicholas J.: Plant coexistence in coastal heaths: Habitat segregation in the Post-Fire Environment. In: Australian Journal of Ecology. 21. Jahrgang, 1996, S. 47–54 (http://www.une.edu.au/ers/staff-profile-doc-folders/peter-clarke/1996-myerscough-et-al-aust-j-ecology.pdf (fulltext) [PDF]).
  21. ↑ Myerscough, Peter J.; Clarke Peter J.; Skelton Nicholas J.: Plant coexistence in coastal heaths: Between- and within habitat effects of competition, disturbance and predation in the post-fire environment. In: Australian Journal of Ecology. 21. Jahrgang, 1996, S. 55–63 (http://www.une.edu.au/ers/staff-profile-doc-folders/peter-clarke/1996-clarke-et-al-aust-j-ecology.pdf (fulltext) [PDF]).
  22. ↑ Central Threatened Species Unit: Agnes Banks Woodland in the Sydney Basin - profile. In: Threatened species, populations and ecological communities in NSW. Department of Environment and Conservation, New South Wales Government, abgerufen am 8. Juni 2010.
  23. ↑ Byron B. Lamont: Why are hairy root clusters so abundant in the most nutrient-impoverished soils of Australia. In: Plant and Soil. 156. Jahrgang, Nr. 1, 1993, S. 269–72, doi:10.1007/BF00025034.
  24. ↑ Grundon NJ: Mineral Nutrition of Some Queensland Heath Plants. In: Journal of Ecology. 60. Jahrgang, Nr. 1, 1972, S. 171–81.
  25. ↑ a b Damian J. Hackett, Goldingay, Ross L.: Pollination of Banksia spp. by non-flying mammals in north-eastern New South Wales. In: Australian Journal of Botany. 49. Jahrgang, Nr. 5, 2001, S. 637–644, doi:10.1071/BT00004.
  26. ↑ Barker RD; Vestjens WJM: The Food of Australian Birds. Melbourne University Press, 1984, ISBN 0-643-05006-X, '''1''':345, '''2''':242, 458.
  27. ↑ Watson, Penny: The role and use of fire for biodiversity conservation in Southeast Queensland: Fire management guidelines derived from ecological research. In: SEQ Fire and Biodiversity Consortium. National Heritage Trust, Australian Government, Juli 2001, abgerufen am 8. Juni 2010.
  28. ↑ Best practice guidelines Eastern Suburbs Banksia Scrub. Department of Environment and Climate Change NSW, Sydney 2009, ISBN 1 74232 091 5(?!), S. 9 (gov.au [PDF; abgerufen am 8. Juni 2010]).
  29. ↑ a b c d e Kevin Collins, Kathy Collins, Alex S. George: Banksias. Bloomings Books, Melbourne, Victoria 2008, ISBN 1-876473-68-6(?!), S. 100, 141–42.
  30. ↑ Birds Australia: Bird Friendly Spaces: Banksia aemula. In: Birds in Backyards. Birds Australia & Australian Museum, abgerufen am 8. Juni 2010.
  31. ↑ a b Alex S. George: The Banksia Book (Third Edition). Kangaroo Press (in association with the Society for Growing Australian Plants), Kenthurst, New South Wales 1987, ISBN 0-86417-818-2, S. 94–95.
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