Banksia incana

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Hoary banksia
Banksia incana.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Proteales
Family: Proteaceae
Genus: Banksia
Subgenus: Banksia subg. Banksia
Species:
B. incana
Binomial name
Banksia incana
Synonyms [1]

Banksia sphaerocarpa var. glabrescens Meisn.

Banksia incana, commonly known as the hoary banksia, is a species of shrub that is endemic to the south-west of Western Australia. It has hairy stems, narrow linear leaves, heads of bright yellow flowers and later, up to thirty-six follicles covered with greyish hairs in each head.

Contents

Description

Banksia incana grows as a shrub, typically 70 cm (28 in) high and 100 cm (39 in) wide with many stems arising from a woody lignotuber. The stems are covered woolly, greyish hairs. The leaves are narrow linear, 10–60 mm (0.39–2.36 in) long and 1.5–2 mm (0.059–0.079 in) wide on petiole 1–2 mm (0.039–0.079 in) long and with a sharp point on the tip. The flowers are borne on a spherical head 60–70 mm (2.4–2.8 in) in diameter. The flowers are bright yellow, sometimes reddish, the perianth 21–23 mm (0.83–0.91 in) long and the pistil 30–35 mm (1.2–1.4 in) long and hooked. Flowering occurs from November to April and up to thirty-six prominent, egg-shaped follicles, 18–33 mm (0.71–1.30 in) long, 4–15 mm (0.16–0.59 in) high and 10–30 mm (0.39–1.18 in) wide form in each head, the old flowers having fallen. The follicles are covered with short, greyish hairs. [2] [3] [4] [5]

Taxonomy

Carl Meissner noted the hoary banksia as a distinct form of Banksia sphaerocarpa and in 1856 gave it the name Banksia sphaerocarpa var. glabrescens in de Candolle's Prodromus Systematis Naturalis Regni Vegetabilis . [6] [7]

Alex George raised the variety to species status in his 1981 monograph "The genus Banksia L.f. (Proteaceae)", based on a specimen he collected outside the Moore River Native Settlement, on 2 February 1967. [8] He placed it in subgenus Banksia because of its flower spike, in section Oncostylis because its styles are hooked and in the resurrected series Abietinae, which he constrained to contain only round-fruited species. The specific epithet (incana) is from the Latin incanus ("hoary") and refers to the grey furry follicles. [4]

In 2008, George describe two subspecies and the names are accepted by the Australian Plant Census:

The variety brachyphylla was described from a specimen collected at Big Soak Plain on the Coorow-Green Head road on 23 November 1999 . [12]

Distribution and habitat

Banksia incana grows in sand in heath, shrubland or woodland, often with B. attenuata and B. menziesii and occurs between the Arrowsmith River and Perth. [4] [2] [13]

Variety brachyphylla is found between Arrowsmith and Mogumber with disjunct populations near Gingin and Perth. [10] [14]

Ecology

Banksia incana resprouts from its woody lignotuber after bushfire. [15]

Banksia incana is one of five closely related Banksia species that have highly unusual flower nectar. [lower-alpha 1] 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, and eventually becoming "an almost black, gelatinous lump adhering to the base of the flowers". [17] It was first noted by Byron Lamont in 1980; he attributed it to cyanobacteria that feed 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 by Barrett and Lamont in 1985, but no evidence of nitrogen fixing was found. [18] Further investigation by Markey and Lamont 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". Their analyses indicated that the nectar had unusually high levels of sugar and free amino acids, [19] but three of these species, including B. sphaerocarpa, have since been shown to have normal nectar sugar compositions. [20] The purpose of coloured nectar is unclear, especially as pollinators such as nocturnal mammals are not thought to forage by sight. However, nectar that becomes more obvious by appearance or smell as it ages might encourage pollinators to prioritise it over newer nectar. It is possible the colour change is unrelated to pollination. [16]

Conservation status

Both varieties of B. incana are classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife. [13] [14]

Use in horticulture

Seeds do not require any treatment, and take around 14 days to germinate. [21]

Notes

  1. ↑ The other four species are Banksia sphaerocarpa , B. grossa , B. leptophylla and B. telmatiaea . [16]

Related Research Articles

<i>Banksia attenuata</i> Species of plant in the family Proteaceae found across much of the southwest of Western Australia

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.

<i>Banksia conferta</i> Species of shrub in the family Proteaceae endemic to eastern Australia

Banksia conferta, commonly known as the glasshouse banksia, is a species of shrub that is endemic to eastern Australia. It has rough, bark on the trunk, elliptic to egg-shaped leaves arranged in whorls, crowded yellow flowers in a cylindrical spike later forming a relatively large number of follicles.

<i>Banksia elegans</i> Species of shrub in the family Proteaceae endemic to Western Australia

Banksia elegans, commonly known as the elegant banksia, is a species of woody shrub that is endemic to a relatively small area of Western Australia. Reaching 4 m (13 ft) high, it is a suckering shrub that rarely reproduces by seed. The round to oval yellow flower spikes appear in spring and summer. Swiss botanist Carl Meissner described Banksia elegans in 1856. It is most closely related to the three species in the subgenus Isostylis.

<i>Banksia grossa</i> Shrub in the family Proteaceae endemic to Southwest Australia

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.

<i>Banksia laricina</i> Species of shrub in the family Proteaceae endemic to southwestern Western Australia

Banksia laricina, commonly known as the rose banksia, is a species of shrub that is endemic to southwestern Western Australia. It has crowded, linear leaves with a short point on the tip, golden brown flowers with a bright yellow style and prominent egg-shaped follicles.

<i>Banksia leptophylla</i> Species of shrub in the family Proteaceae native to Western Australia

Banksia leptophylla is a species of shrub that is endemic to the south-west of Western Australia. It has narrow linear leaves, heads of yellow or pale brown flowers with a yellow or purple style and later, up to eight egg-shaped follicles in each head.

<i>Banksia nutans</i> Species of shrub in the family Proteaceae native to the south coast of Western Australia

Banksia nutans, commonly known as nodding banksia, is a species of shrub native to the south coast of Western Australia in the genus Banksia. Growing to a metre (3 ft) tall, it has pale blue-green fine-leaved foliage and unusual purple-brown inflorescences which hang upside down rather than grow upright like most other banksias.

<i>Banksia quercifolia</i> Species of shrub in the family Proteaceae from the south coast of Western Australia

Banksia quercifolia, commonly known as the oak-leaved banksia, is a species of shrub that is endemic to the southwestern coast of Western Australia. It has smooth, greenish bark, wavy, wedge-shaped, serrated leaves, yellow, orange or brown flowers in cylindrical spikes, followed by broadly linear follicles surrounded by the remains of the flowers.

<i>Banksia scabrella</i> Species of woody shrub in the family Proteaceae from Western Australia

Banksia scabrella, commonly known as the Burma Road banksia, is a species of woody shrub in the genus Banksia. It is classified in the series Abietinae, a group of several species of shrubs with small round or oval inflorescences. It occurs in a number of isolated populations south of Geraldton, Western Australia, with the largest population being south and east of Mount Adams. Found on sandy soils in heathland or shrubland, it grows to 2 m (7 ft) high and 3 m (10 ft) across with fine needle-like leaves. Appearing in spring and summer, the inflorescences are round to oval in shape and tan to cream with purple styles. Banksia scabrella is killed by fire and regenerates by seed.

<i>Banksia speciosa</i> Large shrub or small tree in the family Proteaceae found on the south coast of Western Australia

Banksia speciosa, commonly known as the showy banksia, is a species of large shrub or small tree in the family Proteaceae. It is found on the south coast of Western Australia between Hopetoun (33°57′ S) and the Great Australian Bight, growing on white or grey sand in shrubland. Reaching up to 8 m (26 ft) in height, it is a single-stemmed plant that has thin leaves with prominent triangular "teeth" along each margin, which are 20–45 cm (7.9–17.7 in) long and 2–4 cm (0.8–1.6 in) wide. The prominent cream-yellow flower spikes known as inflorescences appear throughout the year. As they age they develop up to 20 follicles each that store seeds until opened by fire. Though widely occurring, the species is highly sensitive to dieback and large populations of plants have succumbed to the disease.

<i>Banksia sphaerocarpa</i> Shrub or tree in the family Proteaceae widely distributed across the southwest of Western Australia

Banksia sphaerocarpa, commonly known as the fox banksia or round-fruit banksia, is a species of shrub or tree in the plant genus Banksia. It is generally encountered as a 1–2 m (3.3–6.6 ft) high shrub, and is usually smaller in the north of its range. This species has narrow green leaves, and brownish, orange or yellow round flower spikes which may be seen from January to July. It is widely distributed across the southwest of Western Australia, growing exclusively in sandy soils. It is usually the dominant plant in scrubland or low woodland. It is pollinated by, and is a food source for, birds, mammals, and insects.

<i>Banksia telmatiaea</i> Australian shrub that grows in marshes and swamps

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.

<i>Banksia violacea</i> Species of plant

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.

<i>Banksia micrantha</i> Species of shrub in the family Proteaceae endemic to the south-west of Western Australia

Banksia micrantha is a species of small shrub that is endemic to the south-west of Western Australia. It is a spreading bush with sharply-pointed linear leaves, pale yellow flower spikes and up to twenty-five follicles surrounded by the remains of the flowers. It was first formally described by Alex George in 1981.

<i>Banksia armata</i> Species of shrub in the family Proteaceae endemic to Western Australia

Banksia armata, commonly known as prickly dryandra, is a species of often sprawling shrub that is endemic to Western Australia. It has deeply serrated leaves with sharply pointed lobes and spikes of about 45 to 70 yellow flowers.

<i>Banksia tenuis</i> Species of shrub in the family Proteaceae endemic to Western Australia

Banksia tenuis is a species of shrub that is endemic to the southwest of Western Australia. It has pinnatifid, serrated or smooth-edges leaves, golden brown and cream-coloured flowers in heads of about fifty-five and glabrous, egg-shaped follicles.

Benthams taxonomic arrangement of Banksia 1870 arrangement of the Australian endemic plant genus Banksia

George Bentham's taxonomic arrangement of Banksia was published in 1870, in Volume 5 of Bentham's Flora Australiensis. A substantial improvement on the previous arrangement, it would stand for over a century. It was eventually replaced by Alex George's 1981 arrangement, published in his classic monograph The genus Banksia L.f. (Proteaceae).

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.

Georges taxonomic arrangement of Banksia 1981 and 1996 arrangements of the Australian endemic plant genus Banksia

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.

<i>Banksia sphaerocarpa <span style="font-style:normal;">var.</span> dolichostyla</i> Variety of shrub

Banksia sphaerocarpa var. dolichostyla, commonly known as Ironcap Banksia, is a plant which is either considered a variety of Banksia sphaerocarpa, or as a species in its own right. It is native to the Southwest Botanical Province of Western Australia. Seeds do not require any treatment, and take around 33 days to germinate.

References

  1. 1 2 "Banksia incana". Australian Plant Census. Retrieved 7 May 2020.
  2. 1 2 "Banksia incana". FloraBase . Western Australian Government Department of Biodiversity, Conservation and Attractions.
  3. ↑ George, Alex S. (1999). Flora of Australia (PDF). Vol. 17B. Canberra: Australian Biological Resources Study, Canberra. pp. 243–244. Retrieved 8 May 2020.
  4. 1 2 3 George, Alex (1981). "The genus Banksia L.f. (Proteaceae)". Nuytsia. 3 (3): 441–444. Retrieved 8 May 2020.
  5. ↑ George, Alex S. (1996). The Banksia Book (3rd ed.). Kenthurst, New South Wales: Kangaroo Press. pp. 218–219. ISBN   0-86417-818-2.
  6. ↑ "Dryandra sphaerocarpa var. glabrescens". APNI. Retrieved 8 May 2020.
  7. ↑ Meissner, Carl; de Candolle, Augustin P. (ed.) (1856). Prodromus Systematis Naturalis Vegetabilis. Paris: Sumptibus Victoris Masson. p. 453. Retrieved 8 May 2020.{{cite book}}: |first2= has generic name (help)
  8. ↑ "Banksia incana". APNI. Retrieved 8 May 2020.
  9. ↑ "Banksia incana var. brachyphylla". Australian Plant Census. Retrieved 8 May 2020.
  10. 1 2 3 George, Alex S. (2008). "Further new taxa in Banksia (Proteaceae: Grevilleoideae)" (PDF). Nuytsia. 18: 55–56. Retrieved 8 May 2020.
  11. ↑ "Banksia incana var. incana". Australian Plant Census. Retrieved 8 May 2020.
  12. ↑ "Banksia incana var. brachyphylla". APNI. Retrieved 8 May 2020.
  13. 1 2 "Banksia incana var. incana". FloraBase . Western Australian Government Department of Biodiversity, Conservation and Attractions.
  14. 1 2 "Banksia incana var. brachyphylla". FloraBase . Western Australian Government Department of Biodiversity, Conservation and Attractions.
  15. ↑ George, Alex S. (1999). "Banksia". In Wilson, Annette (ed.). Flora of Australia . Vol. 17B. Collingwood, Victoria: CSIRO Publishing / Australian Biological Resources Study. pp. 175–251. ISBN   0-643-06454-0.
  16. 1 2 Hansen, Dennis M.; Olesen, Jens M.; Mione, Thomas; Johnson, Steven D.; Müller, Christine B. (2007). "Coloured Nectar: Distribution, Ecology, and Evolution of an Enigmatic Floral Trait" (PDF). Biological Reviews. 82 (1): 83–111. doi:10.1111/j.1469-185X.2006.00005.x. ISSN   1469-185X. PMID   17313525. S2CID   21719506.
  17. ↑ Lamont, Byron B. (1980). "Blue-green Algae in Nectar of Banksia aff. Sphaerocarpa". West Australian Naturalist. 14 (7): 193–94.
  18. ↑ Barrett, Gregory J.; Lamont, Byron B. (1985). "Absence of Nitrogen Fixation (Acetylene Reduction) by Procaryotes in Nectar of Banksias". Plant and Soil. 85 (3): 443–45. doi:10.1007/BF02220200. S2CID   39550788.
  19. ↑ Markey, Adrienne S.; Lamont, Byron B. (1996). "Why do Some Banksias have Green Nectar?". International Symposium on the Biology of Proteaceae. Royal Botanic Gardens, Melbourne. (only abstract sighted)
  20. ↑ Nicolson, Susan W.; Van Wyk, Ben-Erik (1998). "Nectar Sugars in Proteaceae: Patterns and Processes". Australian Journal of Botany. 46 (4): 489–504. doi:10.1071/BT97039. ISSN   0067-1924.
  21. ↑ Sweedman, Luke; Merritt, David, eds. (2006). Australian seeds: a guide to their collection, identification and biology. CSIRO Publishing. p. 203. ISBN   0-643-09298-6.
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