| Banksia rosserae | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Proteales |
| Family: | Proteaceae |
| Genus: | Banksia |
| Species: | B. rosserae |
| Binomial name | |
| Banksia rosserae Olde & Marriott | |
Banksia rosserae is a recently described species of Banksia . Endemic to inland Western Australia, it is the only Banksia species to occur solely within the arid zone.
B. rosserae grows as a multi-stemmed shrub 2.5 to 3 metres (8.2 to 9.8 ft) high, and 3 to 4 metres (9.8 to 13.1 ft) wide. The trunks are from 10 to 15 centimetres (3.9 to 5.9 in) in diameter. Unusually for Banksia species, the grey bark is papery and flaky. The leaves are dark green, 5 to 12 centimetres (2.0 to 4.7 in) long and 5 to 12 millimetres (0.20 to 0.47 in) wide, with serrated margins. Flowers are yellow and occur in Banksia's distinctive flower spikes; these are approximately spherical, with a diameter of about 5 centimetres (2 in). The "cones" have a hairy appearance due to the retention of old flower parts. They typically contain from twelve to twenty follicles, most of which do not open until stimulated to do so by fire.
Reports of who first discovered B. rosserae are somewhat contradictory. Peter Olde and Neil Marriott acknowledge Ann Pilkington of Kirkalocka, "who discovered Banksia rosserae and who drew it to our attention through various third parties." [1] However, Kevin Collins states that it was first discovered in September 2000 by a Grevillea enthusiast named John Cullen. According to Collins, Cullen had visited Kirkalocka in search of an undescribed Grevillea species mentioned in the writings of Charles Gardner (now published as G. kirkalocka ); in addition to finding the Grevillea, he also found two B. rosserae plants growing on the top of an orange sand dune. [2]
Irrespective of who first discovered it, its presence in the area was reported to Peter Olde and Neil Marriott. In 2001, Olde, Marriott and Keith Alcock visited the area in search of the undescribed Grevillea species. While there, they also searched for the Banksia, and eventually Alcock located two specimens growing on top of a dune. The plants were clearly an undescribed species, so specimens were collected so that a formal description of the species could be published. [3] The following year it was published as Banksia rosserae Olde & Marriott. [4] The name honours Celia Rosser, an illustrator, whose three-volume monograph The Banksias has been acclaimed as one of 20th century's great works of botanical illustration. [5]
In January 2002, Kevin Collins and John Cullen undertook a search for more plants, locating a clump of six plants about 20 kilometres (12 mi) from the original two, and a further 18 plants on crown land adjacent to Kirkalocka. No flowering specimen was seen during these visits; indeed, no-one knew what the flower looked like until 2006. In March of that year, storms associated with Cyclone Glenda dumped a year's worth of rain in the area in a single day, and shortly afterwards, flowers began to form. Two months later, a party of botanists and Banksia enthusiasts visited the area, and observed the flowers for the first time. [5]
B. rosserae's relationship to other Banksia species is uncertain. Its leaves are virtually indistinguishable from narrow-leaved forms of B. laevigata (Tennis Ball Banksia), and like that species it has condensed, roughly spherical inflorescences, and slender styles. However, unlike B. laevigata it has a lignotuber, and terminal inflorescences that hang down instead of being held erect. The lignotuber suggests an affinity with B. lullfitzii , while the pendulous inflorescences suggest a relationship with the Banksia ser. Tetragonae series.
Olde and Marriott provisionally placed it in subgenus Banksia because its inflorescences take the form of Banksia's characteristic flower spikes; Banksia sect. Banksia because of its straight styles; and Banksia ser. Cyrtostylis because it has slender flowers. It was placed alongside B. laevigata, but with the proviso that "we have perceived a close relationship between Banksia laevigata and Banksia rosserae which a more informed study may find superficial." [1]
B. rosserae's current placement within Banksia may be summarised as follows:
A 2013 molecular study by Cardillo and colleagues using chloroplast DNA found that B. rosserae was sister species to a clade made up of Banksia meisneri adscendens and Banksia pulchella , and the three together were sister to Banksia meisneri meisneri. [6]
Banksia rosserae is known only from an area south-south-east of Mount Magnet in inland Western Australia. There are 27 plants known, all occurring within a radius of about 20 kilometres (12 mi). The area is around 200 kilometres (125 mi) from where other Banksia species are known to occur, representing "a significant extension of range into the arid zone and a significant geographic disjunction for the genus." [1]
Although most of the land around Mount Magnet has the heavy clay soil and Acacia aneura (Mulga) scrub common throughout semi-arid Western Australia, the area on which B. rosserae occurs is unusual in having deep yellow sand and laterite. It occurs there with mallee Eucalyptus species, over open heath of Grevillea , Hakea , Leptospermum , Melaleuca , Cryptandra and Triodia species. Thus the flora is more like that found on the Swan Coastal Plain than the arid zone in which it occurs.
Very little is known of the ecology of B. rosserae. Its massive lignotuber is clearly an adaptation to desert conditions, providing a store of water during extended periods of drought, and a store of energy from which it can resprout after bushfire. Marriott also considers its papery bark to be an adaptation to desert conditions, although he does not elaborate on how the plant benefits from it. [3]
Flowering apparently occurs only after rain, and hence may be separated by periods of many years. [5] Pollinators have not been recorded for the species, but extensive data from other Banksia species suggests that insects, birds and nectariferous mammals would all play a role.[ citation needed ] There is clearly no shortage of pollinators, as most "cones" contain plenty of follicles. [3] Although most follicles observed are closed, a few open ones have been found, suggesting that the species is weakly serotinous: that is, a few follicles open spontaneously or in response to rain, but most remain closed until burnt. [2]
Seedlings would have little chance of surviving in a normal dry season; establishment probably requires several consecutive seasons of good rain. [3] The combination of a bushfire followed by several seasons of cyclonic storms probably only occurs every few hundred years, suggesting that opportunities for seedling recruitment are extremely rare. This would explain why the entire population appears to be over two hundred years old. [5]
There is little information on threats to the species. All known plants appear to be in very good health and free of pests; it seems they are not eaten or damaged by the area's kangaroos, goats and sheep. [2] Bushfire clearly poses no threat; and the area is free from Phytophthora cinnamomi dieback, a scourge of most other western Banksia species. [7] Any concerns about future land use are abated by the fact that the largest population occurs on crown land, which is now being considered for a conservation reserve. [2] In fact, the only perceived threat is the rarity of conditions conducive to seedling recruitment: "it may well be that this banksia has become so adapted to its harsh environment that its long-term future in the wild is in doubt." [3]
Because of the absence of any specific threat to the species, it has not been declared rare or threatened. However, Olde and Marriott declared it to merit Priority One listing on the Department of Environment and Conservation's Declared Rare and Priority Flora List. Consequently, they withheld the precise location of their specimens "for conservation reasons". [1]
Banksia rosserae is poorly known in cultivation as yet. In 2003, Kevin Collins reported that "early trials have proven good seed viability and rapid young seedling development". [2] The following year Neil Marriott reported that "seedlings germinate well with smoked water during spring, and young plants establishing here in deep granite sands and sandy loams at Stawell are growing slowly but steadily." It was his view that the species was likely to be of value to the cut flower industry, and as a garden plant in hot dry climates. [3]
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 serrata, commonly known as the saw banksia, the old man banksia, the saw-tooth banksia or the red honeysuckle and as wiriyagan by the Cadigal people, is a species of woody shrub or tree of the genus Banksia, in the family Proteaceae. Native to the east coast of Australia, it is found from Queensland to Victoria with outlying populations on Tasmania and Flinders Island. Commonly growing as a gnarled tree up to 16 m (50 ft) in height, it can be much smaller in more exposed areas. This Banksia species has wrinkled grey bark, shiny dark green serrated leaves and large yellow or greyish-yellow flower spikes appearing over summer. The flower spikes, or inflorescences, turn grey as they age and pollinated flowers develop into large, grey, woody seed pods called follicles.
Banksia petiolaris is a rare species of flowering plant in the family Proteaceae native to Western Australia, where it is found in sandy soils in the south coastal regions from Munglinup east to Israelite Bay. It was first described by Victorian state botanist Ferdinand von Mueller in 1864, and no subspecies are recognised. B. petiolaris is one of several closely related species that will all grow as prostrate shrubs, with horizontal stems and thick, leathery upright leaves. Those of this species can be viable for up to 13 years—the longest-lived of any flowering plant recorded. It bears yellow cylindrical flower spikes, known as inflorescences, up to 16 cm high in spring. As the spikes age, they turn grey and develop up to 20 woody seed pods, known as follicles, each.
Banksia attenuata, commonly known as the candlestick banksia, slender banksia, or biara to the Noongar people, is a species of plant in the family Proteaceae. Commonly a tree, it reaches 10 m (33 ft) high, but it is often a shrub in drier areas 0.4 to 2 m high. It has long, narrow, serrated leaves and bright yellow inflorescences, or flower spikes, held above the foliage, which appear in spring and summer. The flower spikes age to grey and swell with the development of the woody follicles. The candlestick banksia is found across much of the southwest of Western Australia, from north of Kalbarri National Park down to Cape Leeuwin and across to Fitzgerald River National Park.
As with other flowering plants, the taxonomy of Banksia has traditionally been based on anatomical and morphological properties of the Banksia flower, fruiting structure and seed, along with secondary characteristics such as leaf structure and growth habit. Increasingly, molecular evidence from DNA is providing important new insights into relationships within the genus and between this and other genera in the Proteaceae.
Banksia aculeata, commonly known as prickly banksia, is a species of plant of the family Proteaceae native to the Stirling Range in the southwest of Western Australia. A shrub up to 2 m (7 ft) tall, it has dense foliage and leaves with very prickly serrated margins. Its unusual pinkish, pendent (hanging) flower spikes, known as inflorescences, are generally hidden in the foliage and appear during the early summer. Although it was collected by the naturalist James Drummond in the 1840s, Banksia aculeata was not formally described until 1981, by Alex George in his monograph of the genus.
Banksia caleyi, commonly known as Caley's banksia or red lantern banksia, is a species of woody shrub of the family Proteaceae native to Western Australia. It generally grows as a dense shrub up to 2 m (7 ft) tall, has serrated leaves and red, pendent (hanging) inflorescences which are generally hidden in the foliage. First described by Scottish naturalist Robert Brown in 1830, Banksia caleyi was named in honour of the English botanist George Caley. No subspecies are recognised. It is one of three or four related species with hanging inflorescences, which is an unusual feature within the genus.
Banksia grossa is a species of shrub in the family Proteaceae and is endemic to Southwest Australia. It is one of fourteen species of banksia of the series Abietinae, all of which bear predominantly cylindrical or oval inflorescences. Collected in 1965, it was first formally described in 1981 by Alex George. Its thick leaves and large seeds distinguish it from other members of the Abietinae, and are the basis of its species name.
Banksia lemanniana, the yellow lantern banksia or Lemann's banksia, is a species of flowering plant in the family Proteaceae, native to Western Australia. It generally grows as an open woody shrub or small tree to 5 m (16 ft) high, with stiff serrated leaves and unusual hanging inflorescences. Flowering occurs over summer, the greenish buds developing into oval flower spikes before turning grey and developing the characteristic large woody follicles. It occurs within and just east of the Fitzgerald River National Park on the southern coast of the state. B. lemanniana is killed by bushfire and regenerates from seed.
Banksia telmatiaea, commonly known as swamp fox banksia or rarely marsh banksia, is a shrub that grows in marshes and swamps along the lower west coast of Australia. It grows as an upright bush up to 2 metres 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 separate species until 1981; as with several other similar species it was previously included in B. sphaerocarpa.
Banksia violacea, commonly known as violet banksia, is a species of shrub or tree in the plant genus Banksia. It generally grows as a small shrub to 1.5 m (5 ft) high with fine narrow leaves, and is best known for its unusually coloured dark purple-violet inflorescences. The colour of the inflorescences, short leaves, and flattened follicles which are sticky when young, help identify this species from others in the field. It is found in low shrubland in southern regions of Western Australia from Esperance in the east to Narrogin in the west, growing exclusively in sandy soils.
Banksia blechnifolia is a species of flowering plant in the genus Banksia found in Western Australia. It was first described by Victorian state botanist Ferdinand von Mueller in 1864, and no subspecies are recognised. It gained its specific name as its leaves are reminiscent of a fern (Blechnum). B. blechnifolia is one of several closely related species that grow as prostrate shrubs, with horizontal stems and leathery, upright leaves. The red-brown flower spikes, known as inflorescences, are up to 20 centimetres (8 in) high and appear from September to November in the Australian spring. As the spikes age, each turns grey and develops as many as 25 woody seed pods, known as follicles.
The ecology of Banksia is the relationships and interactions among the plant genus Banksia and its environment. Banksia has a number of adaptations that have so far enabled the genus to survive despite dry, nutrient-poor soil, low rates of seed set, high rates of seed predation and low rates of seedling survival. These adaptations include proteoid roots and lignotubers; specialised floral structures that attract nectariferous animals and ensure effective pollen transfer; and the release of seed in response to bushfire.
Banksia epica is a shrub that grows on the south coast of Western Australia. A spreading bush with wedge-shaped serrated leaves and large creamy-yellow flower spikes, it grows up to 3½ metres (11½ ft) high. It is known only from two isolated populations in the remote southeast of the state, near the western edge of the Great Australian Bight. Both populations occur among coastal heath on cliff-top dunes of siliceous sand.
"The genus Banksia L.f. (Proteaceae)" is a 1981 monograph by Alex George on the taxonomy of the plant genus Banksia. Published by the Western Australian Herbarium as Nuytsia3(3), it presented George's taxonomic arrangement of Banksia, the first major taxonomic revision of the genus since George Bentham published his arrangement in Flora Australiensis in 1870.
Banksia ser. Cyrtostylis is a taxonomic series within the plant genus Banksia. First published at sectional rank by George Bentham in 1870, it was demoted to a series by Alex George in 1981. The name has had three circumscriptions.
Kevin Thiele and Pauline Ladiges taxonomic arrangement of Banksia, published in 1996, was a novel taxonomic arrangement that was intended to align the taxonomy of Banksia more closely with the phylogeny that they had inferred from their cladistic analysis of the genus. It replaced Alex George's 1981 arrangement, but most aspects were not accepted by George, and it was soon replaced by a 1999 revision of George's arrangement. However some herbaria have continued to follow Thiele and Ladiges on some points.
Alex George's taxonomic arrangement of Banksia was the first modern-day arrangement for that genus. First published in 1981 in the classic monograph The genus Banksia L.f. (Proteaceae), it superseded the arrangement of George Bentham, which had stood for over a hundred years. It was overturned in 1996 by Kevin Thiele and Pauline Ladiges, but restored by George in 1999. A recent publication by Austin Mast and Kevin Thiele suggests that it will soon be overturned again.
Grevillea kirkalocka is a species of flowering plant in the family Proteaceae and is endemic to inland Western Australia. It is a low, spreading shrub with divided leaves with sharply-pointed linear lobes and clusters of red flowers.
