Banksia densa

Priority Two — Poorly Known Taxa (DEC)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Proteales
Family: Proteaceae
Genus: Banksia
Subgenus: Banksia subg. Banksia
Series: Banksia ser. Dryandra
Species:
B. densa
Binomial name
Banksia densa
Synonyms[1]

Banksia densa is a species of column-like shrub that is endemic to Western Australia. It has deeply serrated to pinnatifid leaves, creamy yellow flowers in heads of up to seventy-five, and hairy follicles.

Description

Banksia densa is a shrub, usually with a column-like form that typically grows to a height of 2.5 m (8 ft 2 in) but does not form a lignotuber. It has linear, pinnatifid leaves that are 50–150 mm (2.0–5.9 in) long and 8–15 mm (0.31–0.59 in) wide on a petiole up to 10 mm (0.39 in) long. There are between eight and thirteen sharply pointed linear to triangular lobes up to 9 mm (0.35 in) long on each side of the leaves and the lower surface is covered with woolly white hairs. The flowers are arranged in heads of between forty and seventy-five with rusty-hairy or velvety, linear involucral bracts up to 15 mm (0.59 in) long at the base of the head. The flowers have a creamy yellow, hairy perianth 15–18 mm (0.59–0.71 in) or 21–25 mm (0.83–0.98 in) long, depending on subspecies, and a mostly glabrous pistil 16–26 mm (0.63–1.02 in) long or 25–30 mm (0.98–1.18 in) long. Flowering occurs from May to October and the fruit is a hairy, egg-shaped to elliptical follicle 9–13 mm (0.35–0.51 in) long.[2][3][4]

Taxonomy and naming

This species was first formally described in 1870 by George Bentham who gave it the name Dryandra conferta and published the description in Flora Australiensis.[5][6] The specific epithet (conferta) is from a Latin word meaning "crowded".[7]

In 1996, Alex George described two varieties:[4]

  • Dryandra conferta var. conferta with a perianth 21–25 mm (0.83–0.98 in) long and a pistil 25–30 mm (0.98–1.18 in) long and flowers with a mouse-like or honey-like scent;
  • Dryandra conferta var. parva with a perianth 15–18 mm (0.59–0.71 in) long and a pistil 16–26 mm (0.63–1.02 in) long.

In 2007, Austin Mast and Kevin Thiele transferred all Dryandra species to Banksia. As there was already a species named Banksia conferta, Mast and Thiele changed the specific epithet to "densa".[8][9]

The changed names of the varieties are as follows and are accepted at the Australian Plant Census:

Distribution and habitat

Banksia densa is widespread in inland parts of the south-west of Western Australia, growing in kwongan, woodland and shrubland between Miling, Cadoux the Porongorups, Bodallin and Mount Holland. Variety parva has a more southerly distribution than var. densa.[4][3]

Ecology

An assessment of the potential impact of climate change on this species found that its range is likely to contract by between 50% and 80% by 2080, depending on the severity of the change.[12]

Conservation status

This banksia is classified as "Priority Two" by the Western Australian Government Department of Parks and Wildlife[2] meaning that it is poorly known and from only one or a few locations.[13]

References

  1. 1 2 "Banksia densa". Australian Plant Census. Retrieved 22 April 2020.
  2. 1 2 "Banksia densa". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  3. 1 2 George, Alex S. (1999). Flora of Australia (PDF). Vol. 17B. Canberra: Australian Biological Resources Study, Canberra. pp. 344–346. Retrieved 22 April 2020.
  4. 1 2 3 George, Alex S. (1996). "New taxa and a new infrageneric classification in Dryandra R.Br". Nuytsia. 10 (3): 387–388.
  5. ↑ "Dryandra conferta". APNI. Retrieved 22 April 2020.
  6. ↑ Bentham, George; von Mueller, Ferdinand (1870). Flora Australiensis (Volume 5). London: Lovell Reeve & Co/. p. 578. Retrieved 22 April 2020.
  7. ↑ Francis Aubie Sharr (2019). Western Australian Plant Names and their Meanings. Kardinya, Western Australia: Four Gables Press. p. 168. ISBN 9780958034180.
  8. ↑ "Banksia densa". APNI. Retrieved 22 April 2020.
  9. ↑ Mast, Austin R.; Thiele, Kevin (2013). "The transfer of Dryandra R.Br. to Banksia L.f. (Proteaceae)". Australian Systematic Botany. 20 (1): 63–71. doi:10.1071/SB06016.
  10. ↑ "Banksia densa var. densa". Australian Plant Census. Retrieved 22 April 2020.
  11. ↑ "Banksia densa var. parva". Australian Plant Census. Retrieved 22 April 2020.
  12. ↑ Fitzpatrick, Matthew C.; Gove, Aaron D.; Sanders, Nathan J.; Dunn, Robert R. (2008). "Climate change, plant migration, and range collapse in a global biodiversity hotspot: the Banksia (Proteaceae) of Western Australia". Global Change Biology. 14 (6): 1–16. doi:10.1111/j.1365-2486.2008.01559.x.
  13. ↑ "Conservation codes for Western Australian Flora and Fauna" (PDF). Government of Western Australia Department of Parks and Wildlife. Retrieved 22 April 2020.
  • Cavanagh, Tony; Pieroni, Margaret (2006). The Dryandras. Melbourne: Australian Plants Society (SGAP Victoria); Perth: Wildflower Society of Western Australia. ISBN 1-876473-54-1.
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