Banksia oblongifolia
Fern-leaved banksia | |
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Banksia oblongifolia, Georges River National Park | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Proteales |
Family: | Proteaceae |
Genus: | Banksia |
Subgenus: | Banksia subg. Banksia |
Section: | Banksia sect. Banksia |
Series: | Banksia ser. Salicinae |
Species: | B. oblongifolia
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Binomial name | |
Banksia oblongifolia | |
Distribution of B. oblongifolia (green) | |
Synonyms[2] | |
Banksia oblongifolia, commonly known as the fern-leaved, dwarf or rusty banksia, is a species in the plant
Spanish botanist
Description
Banksia oblongifolia is a shrub that can reach 3 m (9.8 ft) high,
Flowering has been recorded between January and October, with a peak in autumn and early winter (April to June).[6] The inflorescences, or flower spikes, arise from the end of 1 to 5 year old branchlets, and often have a whorl of branchlets arising from the node or base. Measuring 5–15 cm (2.0–5.9 in) high and 4 cm (1.6 in) wide, the yellow spikes often have blue-grey tinged limbs in bud,[3] though occasionally pinkish, mauve or mauve-blue limbs are seen.[7] Opening to a pale yellow after anthesis, the spikes lose their flowers with age and swell to up to 17.5 cm (6.9 in) high and 4 cm (1.6 in) wide, with up to 80 follicles. Covered with fine fur but becoming smooth with age, the oval-shaped follicles measure 1–1.8 cm (0.39–0.71 in) long by 0.2–0.7 cm high (0.1–0.3 in) and 0.3–0.7 cm (0.12–0.28 in) wide.[3] The bare swollen spike, now known as an infructescence, is patterned with short spiky persistent bracts on its surface where follicles have not developed.[5] Each follicle contains one or two obovate dark grey-brown to black seeds sandwiching a woody separator. Measuring 1.2–1.8 cm (0.47–0.71 in) long, they are made up of an oblong to semi-elliptic smooth or slightly ridged seed body, 0.7–1.1 cm (0.28–0.43 in) long by 0.3–0.7 cm (0.12–0.28 in) wide. The woody separator is the same shape as the seed, with an impression where the seed body lies next to it.[3] Seedlings have bright obovate green cotyledons 1.2–1.5 cm (0.47–0.59 in) long and 0.5–0.7 cm (0.20–0.28 in) wide, which sit on a stalk, or 1 mm diameter finely hairy seedling stem, known as the hypocotyl, which is less than 1 cm high. The first seedling leaves to emerge are paired (oppositely arranged) and lanceolate with fine-toothed margins, measuring 2.5–3 cm long and 0.4–0.5 cm wide. Subsequent leaves are more oblanceolate, elliptic (oval-shaped) or linear. Young plants develop a lignotuber in their first year.[3]
Banksia oblongifolia can be distinguished from B. robur, which it often co-occurs with, by its smaller leaves and bare fruiting spikes. B. robur has more metallic green flower spikes, and often grows in wetter areas within the same region. B. plagiocarpa has longer leaves with more coarsely serrated margins, and its flower spikes are blue-grey in bud, and later bear wedge-shaped follicles.[3] In the Sydney Basin, B. paludosa also bears a superficial resemblance to B. oblongifolia, but its leaves are more prominently spathulate (spoon-shaped) and tend to point up rather than down. The leaf undersides are white and lack the prominent midrib of B. oblongifolia, the new growth is bare and lacks the rusty fur, and the aged flower parts remain on the old spikes.[8]
Taxonomy
First collected by Luis Née between March and April 1793, the fern-leaved banksia was described by Antonio José Cavanilles in 1800 as two separate species from two collections, first as Banksia oblongifolia from the vicinity of Port Jackson (Sydney),[9] and then as Banksia salicifolia from around Botany Bay.[10] Derived from the Latin words oblongus "oblong", and folium "leaf", the species name refers to the shape of the leaves.[11] Richard Anthony Salisbury had published the name Banksia aspleniifolia in 1796 based on leaves of cultivated material.[3]
In 1870,
Botanists in the 20th century recognised B. oblongifolia as a species in its own right, but disagreed on the name. Those in Queensland felt Salisbury's name was invalid and used Banksia oblongifolia, while New South Wales authorities used Banksia aspleniifolia as it was the oldest published name for the species. Botanist and banksia authority Alex George ruled that oblongifolia was the correct name in his 1981 revision of the genus. After reviewing Salisbury's original species description, which is of the leaves alone, he concluded that it does not diagnose the species to the exclusion of others and is hence not a validly published name—the description could have applied to juvenile leaves of B. paludosa, B. integrifolia or even B. marginata.[3]
Placement within Banksia
The current
- Genus Banksia
- Subgenus Isostylis
- Subgenus Banksia
- Section Oncostylis
- Section Coccinea
- Section Banksia
- Series Grandes
- Series Banksia
- Series Crocinae
- Series Prostratae
- Series Cyrtostylis
- Series Tetragonae
- Series Bauerinae
- Series Quercinae
- Series Salicinae
- B. dentata – B. aquilonia – B. integrifolia – B. plagiocarpa – B. oblongifolia – B. robur – B. conferta – B. paludosa – B. marginata – B. canei – B. saxicola
Since 1998, American botanist
Variation
George noted that Banksia oblongifolia showed considerable variation in habit, and in 1987 Conran and Clifford separated the taxon into two subspecies. In examining populations in southern Queensland, they reported that the two forms were distinct in growth habit and habitat, and that they did not find any intermediate forms.[21] New South Wales botanists Joseph Maiden and Julius Henry Camfield had collected this taller form of B. oblongifolia in Kogarah in 1898, and given it the name Banksia latifolia variety minor—B. latifolia being a published name by which B. robur was known—before Maiden and Ernst Betche renamed it Banksia robur variety minor.[3] This name (confusingly) thus became the name for the taller variety. They defined variety oblongifolia as a multistemmed shrub 0.5–1.3 m (20–51 in) high, with leaves 3–11 cm (1.2–4.3 in) long and 1–2.5 cm (0.39–0.98 in) wide, and flower spikes 4–10 cm (1.6–3.9 in) high. The habitat is swamps and swamp borders, or rarely sandstone ridges. Variety minor is a taller shrub 1–3.5 m (3.3–11.5 ft) high with leaves up to 16 cm (6.3 in) long and spikes 6 to 14 cm (2.4 to 5.5 in) high. It is an understory plant in sclerophyll forests, associated with Eucalyptus signata and Banksia spinulosa var. collina. Both subspecies occur throughout the range.[21] However, George rejected the varieties, stating the variability was continuous.[2]
Hybridization
Banksia robur and B. oblongifolia
Distribution and habitat
Banksia oblongifolia occurs along the eastern coast of Australia from
Associated species in the Sydney region include heathland species such as heath banksia (Banksia ericifolia), coral heath (Epacris microphylla) and mountain devil (Lambertia formosa), and tick bush (Kunzea ambigua) and prickly-leaved paperbark (Melaleuca nodosa) in taller scrub, and under trees such as scribbly gum (Eucalyptus sclerophylla) and narrow-leaved apple (Angophora bakeri) in woodland.[6] The Agnes Banks Woodland in western Sydney has been recognised by the New South Wales Government as an Endangered Ecological Community. Here B. oblongifolia is an understory plant in low open woodland, with scribbly gum, narrow-leaved apple and old man banksia (B. serrata) as canopy trees, and wallum banksia (B. aemula), variable smoke-bush (Conospermum taxifolium), wedding bush (Ricinocarpos pinifolius), showy parrot-pea (Dillwynia sericea) and nodding geebung (Persoonia nutans) as other understory species.[23]
Ecology
Banksia oblongifolia plants can live for more than 60 years.[6] They respond to bushfire by resprouting from buds located on the large woody lignotuber. Larger lignotubers have the greatest number of buds, although buds are more densely spaced on smaller lignotubers. A 1988 field study in Ku-ring-gai Chase National Park found that shoots grow longer after fire, particularly one within the previous four years, and that new buds grow within six months after a fire.[24] These shoots are able to grow, flower and set seed two to three years after a fire.[25] The woody infructescences also release seeds as their follicles are opened with heat,[6] although a proportion do open spontaneously at other times. One field study in Ku-ring-gai Chase National Park found 10% opened in the absence of bushfire, and that seeds germinated, and young plants do grow.[26] Older plants are serotinous, that is, they store large numbers of seed in an aerial seed bank in their canopy that are released after fire.[25] Being relatively heavy, the seeds do not disperse far from the parent plant.[6]
Bird species that have been observed foraging and feeding at the flowers include the
One field study found 30% of seeds were eaten by insects between bushfires.[24] Insects recovered from inflorescences include the banksia boring moth (Arotrophora arcuatalis), younger instars of which eat flower and bract parts before tunneling into the woody axis of the spike as they get older and boring into follicles and eating seeds. Other seed predators include unidentified species of moth of the genera Cryptophasa and Xylorycta, as well as Scieropepla rimata, Chalarotona intabescens and Chalarotona melipnoa and an unidentified weevil species.[27] The fungal species Asterina systema-solare, Episphaerella banksiae and Lincostromea banksiae have been recorded on the leaves.[6]
Like most other
Cultivation
Not commonly cultivated,[33] it adapts readily to garden conditions and tolerates most soils in part-shade or full sun.[11] The colours of the inflorescences in bud,[7] and timing of flowers into winter give it horticultural value, as does its reddish new growth.[11] Larger plants have taller flower spikes.[7] It is propagated readily from seed,[11] with young plants taking five to seven years to flower from seed.[7] Pruning can improve the shrub's appearance,[11] and it is a potential bonsai subject.[7]
References
- . Retrieved 27 November 2022.
- ^ ISBN 0-643-06454-0.
- ^ ISSN 0085-4417.
- ^ ISBN 0-644-07124-9.
- ^ ISBN 0-86417-433-0.
- ^ a b c d e f g h Benson, Doug; McDougall, Lyn (2000). "Ecology of Sydney Plant Species Part 7b: Dicotyledon families Proteaceae to Rubiaceae" (PDF). Cunninghamia. 6 (4): 1017–1202 [1035]. Archived from the original (PDF) on 23 June 2014. Retrieved 24 March 2012.
- ^ ISBN 978-1-876473-68-6.
- ISBN 0-7318-1031-7.
- ^ Cavanilles, Antonio José (1800). Anales de Historia Natural (in Spanish). Vol. I. Madrid, Spain: Imprenta Real por P.J. Pereyra. p. 225.
- ^ Cavanilles, Antonio José (1800). Anales de Historia Natural (in Spanish). Vol. I. Madrid, Spain: Imprenta Real por P.J. Pereyra. p. 231.
- ^ ISBN 0-207-17277-3.
- ^ Brown, Robert (1810). Prodromus Florae Novae Hollandiae et Insulae Van Diemen. London: Taylor.
- ^ George, Alex S. (1981). "The Genus Banksia L.f. (Proteaceae)". Nuytsia. 3 (3): 239–473.
- A.P. de Candolle (ed.). Prodromus Systematis Naturalis Regni Vegetabilis, Pars Decima Quarta. Paris, France: Sumptibus Victoris Masson.
- ^ Bentham, George (1870). . Flora Australiensis: Volume 5: Myoporineae to Proteaceae. London, United Kingdom: L. Reeve & Co. pp. 541–62.
- .
- doi:10.1071/SB97026.
- PMID 21665734.
- doi:10.1071/SB04015.
- doi:10.1071/SB06016.
- ^ .
- PMID 20142262.
- ^ Central Threatened Species Unit (1 September 2005). "Agnes Banks Woodland in the Sydney Basin – profile". Threatened species, populations and ecological communities in NSW. Hurstville, New South Wales: Department of Environment and Conservation, New South Wales Government. Retrieved 29 March 2012.
- ^ .
- ^ a b Zammit, Charles; Westoby, Mark (1987). "Population Structure and Reproductive Status of Two Banksia Shrubs at Various Times after Fire". Vegetatio. 70 (1): 11–20.
- JSTOR 2260464.
- .
- ISBN 0-86840-156-0.
- doi:10.1111/j.1442-9993.1995.tb00567.x. Archived from the original(PDF) on 10 June 2011.
- doi:10.1111/j.1442-9993.1996.tb00584.x. Archived from the original(PDF) on 10 June 2011.
- doi:10.1111/j.1442-9993.1996.tb00585.x. Archived from the original(PDF) on 10 June 2011.
- ^ Loddiges, Conrad; Loddiges, George; Loddiges, William (1818). The Botanical Cabinet. Vol. 3. London, United Kingdom: John & Arthur Arch. p. 241.
- ISBN 0-85091-143-5.
External links
- "Banksia oblongifolia". Flora of Australia Online. Department of the Environment and Heritage, Australian Government.