User:Fritzmann2002/Banksia ilicifolia

Banksia ilicifolia, also called holly-leaved banksia, is a tree in the family Proteaceae. Native to southwest Western Australia, it belongs to Banksia subg. Isostylis, a subgenus of three closely related Banksia species with flower heads that are dome-shaped rather than the flower spikes that are normal for Banskia. It grows up to 10 metres (33 ft) tall with a columnar or not normal habit. Both the scientific and common names arise from the similarity of its foliage to that of the English holly Ilex aquifolium; the shiny green leaves generally have very prickly rough margins, although some plants don't have toothed leaves. The heads of the flowers are initially yellow but become red-tinged with age; this acts as a signal to alert birds that the flowers have opened and nectar is available.

Robert Brown described Banksia ilicifolia in 1810. Although Banksia ilicifolia is variable in growth form, with low seaside shrubby forms on the south coast near Albany, there are no recognised varieties as such. Spread out widely, the species can only grow in sandy soil. Unlike its close relatives which are killed by fire and regrow from seed, Banksia ilicifolia regrows after bushfire by regrowing from epicormic buds under its bark. It is rarely harvested.

Description change

 
A large tree, near Waroona

Banksia ilicifolia is a changing species. It usually grows as an straight tree up to 10 metres (33 ft) in height, but some trees along the south coast are very small trees or even spreading shrubs.[1] It is generally a 5 metres (16 ft) high small tree in the Margaret River region.[2] The leaves arising from many short branchlets make a dense foliage close to the trunk and branches.[3]

Banksia ilicifolia has a short and thick trunk up to 50 cm (20 in) in diameter, and rough, fibrous, grey bark which is up to 2 cm (0.8 in) thick.[1] New growth takes place mainly in summer.[4] Young branchlets are covered in hair which they lose after two or three years. Leaves grow on stems less than two years of age, and are arranged in a scattered pattern along the stems although crowded at the apices (branchlet tips). Looking like those of holly, its leaves are a dark shiny green color, and variously obovate (egg-shaped), oval-like, truncate or undulate (wavy) in shape, and 3–10 cm (1–4 in) long. Most of the time serrated, the leaf edges have up to 14 prickly "teeth" separated by broad v- to u-shaped sinuses along each side, although some leaves have areas lacking teeth. The leaves sit atop petioles 0.3–1 cm (0.1–0.4 in) in length. The upper and undersurface of the leaves are first covered in fine hairs but become smooth with age. Flowering takes place from late winter to early summer. The flower heads are dome-shaped flower heads rather than spikes as many other banksias, and arise from stems that are around a year old. No side branchlets grow outwards from the spot where the flower head arises.[1] The flower heads measure 7–9 cm (2.8–3.6 in) in diameter, and bear 60 to 100 individual flowers. The flower heads pass through three colour phases, being initially yellow, then pink, then finally red; before falling away from the head. One to three follicles, or pieces of fruit, grow from fertilised flowers, and remain embedded in the woody base of the flower head. Each follicle bears one or two seeds.[5]


[1]

Taxonomy change

Specimens of B. ilicifolia were first collected by Scottish surgeon Archibald Menzies during the visit of the Vancouver Expedition to King George Sound in September and October 1791, but this collection did not result in the description of the species.[1] It was next collected by Robert Brown in December 1801, during the visit of HMS Investigator to King George Sound.[6] The species was also drawn by the journey's botanical artist Ferdinand Bauer. Like nearly all of Bauer's field drawings of Proteaceae, the original field sketch of B. ilicifolia was destroyed in a Hofburg fire in 1945.[7] A painting based on the drawing can still be found, however, at the Natural History Museum in London.[8]

Distribution and habitat change

 
Distribution of Banksia ilicifolia

A rather easy to find species, the holly-leaved banksia is widely spread within south west Western Australia. It can be found in the wild  within 70 km (45 mi) of the coast, from Mount Lesueur to Augusta, and then east to the Cordinup River east of Albany.[4] In the Margaret River area, it grows on yellow sand plains behind the Leeuwin-Naturaliste Ridge.[2] Almost all plants are to the west (seaward) side of the Darling Scarp, although there are two outlying populations - one near Collie east of Bunbury and the other in the Tonbridge-Lake Muir area near Manjimup. Along the south coast, there is one inland population at Sheepwash Nature Reserve near Narrikup northwest of Albany.[4] The annual rainfall over its area ranges from 600 to 1100 mm (25–45 in).[9]

Banksia ilicifolia grows only on sandy soils; its range ends where heavy soils are found.[4] It likes low-lying areas more. It normally grows in open woodland next to such trees as jarrah (Eucalyptus marginata), candlestick banksia (Banksia attenuata), firewood banksia (B. menziesii) and Western Australian Christmas tree (Nuytsia floribunda).[1][4] Along the south coast, it grows in heath,[4] sometimes forming stands with bull banksia (B. grandis).[10]

References change

  1. 1.0 1.1 1.2 1.3 1.4 1.5 George, Alex S. (1981). "The genus Banksia L.f. (Proteaceae)". Nuytsia. 3 (3): 239–473. ISSN 0085-4417.
  2. 2.0 2.1 Scott, Jane; Negus, Patricia (2005) [2002]. Field Guide to Wildflowers of Australia's South West: Augusta-Margaret River Region. Fremantle, Western Australia: Cape to Cape Publishing. p. 60. ISBN 0-9577729-7-1.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. Tassone, R.A.; Maier, J.D. (1997). "Abundance of Arthropods in Tree Canopies of Banksia Woodland on the Swan Coastal Plain". Journal of the Royal Society of Western Australia. 80: 281–86.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Taylor, Anne; Hopper, Stephen (1988). The Banksia Atlas (Australian Flora and Fauna Series Number 8). Canberra, Australian Capital Territory: Australian Government Publishing Service. pp. 120–21. ISBN 0-644-07124-9.{{cite book}}: CS1 maint: multiple names: authors list (link)
  5. George, A. S. (1999). "Banksia". In Wilson, Annette (ed.) (ed.). Flora of Australia: Volume 17B: Proteaceae 3: Hakea to Dryandra. Collingwood, Victoria: CSIRO Publishing / Australian Biological Resources Study. pp. 175–251. ISBN 0-643-06454-0. {{cite book}}: |editor= has generic name (help)
  6. "Banksia ilicifolia R.Br". Robert Brown's Australian Botanical Specimens, 1801–1805 at the BM. Perth, Western Australia: FloraBase, Western Australian Herbarium. Retrieved 3 June 2012.
  7. Pignatti-Wikus, Erika; Reidl-Dorn, Christa; Mabberley, David (2000). "Ferdinand Bauer's field drawings of endemic Western Australian plants made at King George Sound and Lucky Bay, December 1801 – January 1802. I: Families Brassicaceae, Goodenaceae p.p., Lentibulariaceae, Campanulaceae p.p., Orchidaceae, Pittosporaceae p.p., Rutaceae p.p., Stylidaceae, Xyridaceae". Rendiconti lincei: Scienze fisiche e naturali. s.9, v.11 (2): 69–109.
  8. "Banksia illicifolia, holly-leaved banksia". London, United Kingdom: National History Museum. Retrieved 3 June 2012.
  9. George, Alex S. (1996). The Banksia Book (3rd ed.). Kenthurst, New South Wales: Kangaroo Press. pp. 229–30. ISBN 0-86417-818-2.
  10. Mansergh, Nicholas (1999). "Banksia ilicifolia". Australian Plants Online. Australian Native Plants Society (Australia). Retrieved 1 June 2012.