Banksia telmatiaea

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Swamp Fox Banksia
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Proteales Family: Proteaceae Genus: Banksia Species: B. telmatiaea
Binomial name
Banksia telmatiaea A.S.George

Banksia telmatiaea, commonly known as Swamp Fox Banksia or rarely Marsh Banksia,^[1] is a shrub that grows in marshes and swamps along the lower west coast of Australia. It grows as an upright bush up to two metres (7 ft) tall, with narrow leaves and a pale brown flower spike, which can produce profuse quantities of nectar. First collected in the 1840s, it was not published as a species until 1981; as with several other similar species it was previously included in B. sphaerocarpa (Fox Banksia).

The shrub grows amongst scrubland in seasonally wet lowland areas of the coastal sandplain between Badgingarra and Serpentine in Western Australia. A little studied species, not much is known of its ecology or conservation biology. Reports do suggest, however, that it is pollinated by a variety of birds and small mammals. Like many members of series Abietinae it has not been considered to have much horticultural potential and is rarely cultivated.

Contents 1 Description 2 Taxonomy 2.1 Discovery and naming 2.2 Infrageneric placement 3 Distribution and habitat 4 Ecology 5 Conservation 6 Cultivation 7 References 8 External links

[edit] Description

B. telmatiaea grows as an upright bush up to two metres (7 ft) high. It has hairy stems and branchlets, and straight, narrow leaves from 1½ to three centimetres (½–1 in) long and about a millimetre (¹⁄₁₆ in) wide.^[2]

Flowers occur in "flower spikes", inflorescences made up of hundreds of flower pairs densely packed around a woody axis. B. telmatiaea's inflorescences are roughly spherical, with a diameter of three to five centimetres (1–2 in).^[2] It contains between 500 and 900 golden brown to pale brown flowers,^[3] each of which consists of a tubular perianth made up of four fused tepals, and one long wiry style. The styles are hooked rather than straight, and are initially trapped inside the upper perianth parts, but break free at anthesis. The species generally flowers from April to August, although flowers have been observed as late as November.^[4] They take five to six weeks to develop from bud, then reach anthesis over a period of two weeks. The flowers produce unusually large quantities of nectar; indeed some flowers produce so much that it drips to the ground.^[3]

The fruiting structure is a stout woody "cone", with a hairy appearance caused by the persistence of old withered flower parts.^[2] This may be embedded with up to 70 woody follicles, each of which contains a single seed. As with other Banksia species, only a small proportion of flowers go on to form follicles; in the case of B. telmatiaea, the proportion is around 4% for those "cones" that set some fruit. However, about 80% of fruiting structures set no fruit at all. According to John K. Scott, "there [is] no obvious reason on the basis of morphology of pollination for this lack of seed set".^[3]

[edit] Taxonomy

See also: Taxonomy of Banksia

[edit] Discovery and naming

B. telmatiaea was first collected around 1840 by Ludwig Preiss and James Drummond. For many years it was included in B. sphaerocarpa, but by 1980 it was recognised as a distinct species. In recognition of its distinctness from, yet affinity with, B. sphaerocarpa, it was for a time informally referred to as Banksia aff. Sphaerocarpa.^[5] It was eventually published by Alex George in his 1981 monograph The genus Banksia L.f. (Proteaceae), based on a specimen collected by him on the Brand Highway about 45 km (28 mi) north of Regans Ford on 14 May 1969, and labelled "A. S. George 9309".^[6] George gave it the specific name telmatiaea from the Greek stem telmat-/τελματ- ("the mud of a pond"),^[7] in reference to its swampy habitat.^[6] Thus the full name for the species is Banksia telmatiaea A.S.George.^[8]

[edit] Infrageneric placement

George placed B. telmatiaea in subgenus Banksia because its inflorescence is a typical Banksia flower spike, section Oncostylis because it has hooked styles, and series Abietinae because its inflorescence is roughly spherical. He considered its closest relative to be B. leptophylla (Slender-leaved Banksia), which differs from B. telmatiaea in having longer leaves and larger flowers; yet in his arrangement he placed it between B. scabrella (Burma Road Banksia) and B. laricina (Rose-fruited Banksia).^[6]

In 1996, Kevin Thiele and Pauline Ladiges published the results of a cladistic analysis of morphological characters of Banksia. They retained George's subgenera and many of his series, but discarded his sections. B. ser. Abietinae was found to be very nearly monophyletic, and so retained. It further resolved into four subclades, so Thiele and Ladiges split it into four subseries. B. telmatiaea appeared in the third of these:^[9]

	B. telmatiaea
	B. scabrella B. leptophylla var. melletica B. leptophylla var. leptophylla B. lanata

This clade became the basis of B. subser. Leptophyllae, which Thiele defined as containing those species with "indurated and spinescent common bracts on the unfructescence axes, and densely arachnose seedling stems." In accordance with their cladogram, their arrangement placed B. telmatiaea next to B. scabrella.^[9]

Thiele and Ladiges' arrangement was not accepted by George, and was largely discarded by him in his 1999 arrangement. B. ser. Abietinae was restored to George's 1981 circumscription, and all of Thiele and Ladiges' subseries were abandoned. However, B. telmatiaea was moved in the phyletic order to between B. grossa (Coarse Banksia) and B. leptophylla, thus better according with the affinity with B. leptophylla claimed by George in 1981.^[2]

The placement of B. telmatiaea in George's 1999 arrangement may be summarised as follows:^[2]

Banksia

B. subg. Banksia

B. sect. Banksia (9 series, 50 species, 9 subspecies, 3 varieties)

B. sect. Coccinea (1 species)

B. sect. Oncostylis

B. ser. Spicigerae (7 species, 2 subspecies, 4 varieties)

B. ser. Tricuspidae (1 species)

B. ser. Dryandroideae (1 species)

B. ser. Abietinae

B. sphaerocarpa (3 varieties)

B. micrantha

B. grossa

B. telmatiaea

B. leptophylla (2 varieties)

B. lanata

B. scabrella

B. violacea

B. incana

B. laricina

B. pulchella

B. meisneri (2 subspecies)

B. nutans (2 varieties)

B. subg. Isostylis (3 species)

Since 1998, Austin Mast has been publishing results of ongoing cladistic analyses of DNA sequence data for the subtribe Banksiinae. His analyses suggest a phylogeny that is very greatly different to George's arrangement. With respect to B. telmatiaea, Mast's results accord closely with Thiele and Ladiges' arrangement, inferring a polytomous clade consisting of B. leptophylla, B. telmatiaea, B. scabrella and B. lanata, with B. grossa (Coarse Banksia) as the nearest outgroup:^[10][11][12]

	B. telmatiaea B. scabrella B. leptophylla var. melletica B. leptophylla var. leptophylla B. lanata
	B. grossa

Early in 2007, Mast and Thiele initiated a rearrangement of Banksia by merging Dryandra into it, and publishing B. subg. Spathulatae for the taxa having spoon-shaped cotyledons. 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. telmatiaea is placed in B. subg. Spathulatae.^[13]

[edit] Distribution and habitat

B. telmatiaea grows only in the Swan Coastal Plain, Geraldton Sandplains and Jarrah Forest biogeographic regions, inland from the coast but never east of the Darling Scarp. It occurs from Hill River near Badgingarra in the north, to Serpentine in the south. Most populations occur north of Moore River or south of Cannington, there being only a few scattered populations in between.^[4]

The species favours lowland areas that are seasonally wet but never inundated, such as the margins of swamps and marshes. For example, in the Yule Brook Botany Reserve, where parallel sand ridges cross a clay flat, B. telmatiaea occurs neither in the lowest parts of the flat, where seasonal inundation occurs; nor on the tops of the ridges, where the drainage is good; but it is one of the most abundant plants of intermediate habitats, on ridge slopes and in higher areas of the clay flat.^[14]

Favoured soils are deep grey sandy loams or shallower sand overlying claypan. Associated vegetation is typically scrubland or shrubland, although moisture-loving trees such as B. littoralis (Swamp Banksia) or Melaleuca preissiana (Moonah) may also be present, sometimes in sufficient numbers to form a low open woodland.^[4][15]

[edit] Ecology

See also: Ecology of Banksia

Like most other Proteaceae, B. telmatiaea has 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.^[16]

Unlike many Banksia species, B. telmatiaea lacks a lignotuber, so plants are killed by bushfire. However, it is adapted to release its aerial bank of seeds following a bushfire, and so regenerates rapidly.^[17] This behaviour, known as serotiny, makes B. telmatiaea dependent upon a suitable fire regime for successful regeneration; indeed, excessive fire frequency may be one reason why B. telmatiaea does not occur further south, despite suitable habitat throughout southwest Australia.^[18]

Four species of bird have been observed visiting the flowers of B. telmatiaea: the Red Wattlebird (Anthochaera carunculata),^[4] the Silvereye (Zosterops lateralis), the New Holland Honeyeater (Phylidonyris novaehollandiae) and the Brown Honeyeater (Lichmera indistincta). The introduced Western Honey Bee (Apis mellifera) is also commonly observed, and visits by ants and Hylaeus plasterer bees have been recorded. Visits by nectarivorous mammals have not been directly observed, but their involvement in pollination is certain, as their scats have often been found on inflorescences,^[19] and studies of other Banksia species have consistently demonstrated their involvement.^[20] Moreover, a number of characteristics of the B. telmatiaea spike are purported to be adaptations to pollination by nocturnal mammals: the strong, musky odour,^[19] the occurrence of inflorescences hidden within the foliage close to the ground, the large amounts of nectar produced, and the pattern of nectar production, which peaks at dawn and dusk. This last adaptation is thought to favour visits by birds and mammals, which feed in the morning and evening respectively, as opposed to insects, which are most active during the day.^[15]

Reproductive success is strongly affected by insects that infest the flower spikes and fruiting structures. Infestation of the flower spikes is not as severe as in other Banksia species: one study found less than 10% of B. telmatiaea inflorescences to be infested, compared to over 50% for B. attenuata (Candlestick Banksia), B. littoralis and B. menziesii (Menzies' Banksia), and over 90% for B. grandis (Bull Banksia). Also, whereas other species were attacked by a range of insects, the inflorescence of B. telmatiaea was attacked only by the tortrix moth Arotrophora arcuatalis (Banksia Boring Moth), which burrows into the woody axis, rendering the spike barren. On the other hand, the same study observed heavy infestation of fruiting structures, with over 90% of spikes with follicles found to contain at least one larva of an unidentified species of Xylorycta. These larvae burrow from follicle to follicle to eat the seed, resulting in 100% seed loss for infested spikes.^[3]

B. telmatiaea is one of five Banksia species, all closely related to B. sphaerocarpa, that have highly unusual flower nectar. Whereas other Banksia species produce nectar that is clear and watery, the nectar of these species is pale yellow initially, but gradually becomes darker and thicker, changing to a thick, olive-green mucilage within one to two days of secretion.^[21] In the case of B. telmatiaea, it eventually becomes "an almost black, gelatinous lump adhering to the base of the flowers".^[5] This unusual nectar was first noted in 1980 by Byron Lamont, who attributed it to the cyanobacteria that he observed feeding off the nectar sugars. Noting that many of these cyanobacteria had heterocysts, he speculated that they aid the plant by fixing atmospheric nitrogen, which is then washed off the flower heads by rain, and absorbed by the proteoid root mat. This purported symbiosis was investigated in 1985, but no evidence of nitrogen fixing was found.^[22] Further investigations in 1996 suggested that the discolouration is not caused by cyanobacteria or other microorganisms in the nectar, but is rather "a chemical phenomenon of plant origin".^[21] As of February 2007, the cause was still unknown.^[19] Chemical analysis of B. telmatiaea nectar has shown it to have normal nectar sugar compositions,^[23] albeit sucrose-dominant.^[19]

[edit] Conservation

B. telmatiaea is a fairly secure species, as most populations are of more than 100 plants, and 26% of known plants are in conservation reserves. Its proximity to Perth suggests that land clearing for urban development could pose a threat, and in 1988 The Banksia Atlas recommended that "the species should continue to be monitored since land clearing could change the situation greatly, particularly amongst its northern populations." It is also known to be susceptible to dieback caused by the introduced plant pathogen Phytophthora cinnamomi, a soil-borne water mould that causes root rot.^[24] In fact it is so reliably susceptible that it used as an indicator species for the presence of the disease.^[25]

In 1987, George applied the Rare or Threatened Australian Plants (ROTAP) criteria to the species, determining it to have a conservation status of "3R": a rare species found only in small populations, but not considered endangered or vulnerable.^[17] Western Australia's Department of Environment and Conservation do not consider it to be rare, however, and have not given it a priority code under their system of Conservation Codes for Western Australian Flora.^[26]

[edit] Cultivation

B. telmatiaea is rarely cultivated. It grows fairly quickly, but tends to become untidy as it ages. The flower spikes, though attractive, occur within the bush where they are usually obscured by foliage. In its natural habitat it flowers prolifically over several months, but according to George it may be reluctant to flower in cultivation. It tolerates light pruning not below the green foliage. George recommends a sunny position in poorly drained soil, preferably with moisture in winter.^[17]

[edit] References

[edit] External links

• Banksia telmatiaea A.S.George. Flora of Australia Online. Department of the Environment and Heritage, Australian Government.
• Banksia telmatiaea A.S.George. FloraBase. Department of Environment and Conservation, Government of Western Australia.
• Banksia telmatiaea A.S.George. Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government.