Banksia xylothemelia

Banksia xylothemelia
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
Order:	Proteales
Family:	Proteaceae
Genus:	Banksia
Species:	B. xylothemelia
Binomial name
Banksia xylothemelia (A.S.George) A.R.Mast & K.R.Thiele

Banksia xylothemelia is a sprawling woody shrub of the Proteaceae family endemic to southern Western Australia, one of the many species commonly known as dryandras and until recently called Dryandra xylothemelia. To date it is almost unknown in cultivation.

Description

It grows as a sprawling shrub up to one metre (3 ft) high, often with basal shoots arising from an underground lignotuber. It has woolly stems, and Leaves are pinnatifid with five to nine leaflets on each side, 7 to 12 centimetres long, 4 to 5.5 centimetres wide, smooth above but woolly beneath. Flowers occur in dome shaped heads up to four centimetres across, attached directly to an older stem, or on a short stalk. Flower heads contain from 80 to 100 bright yellow flowers. Each flower consists of a tubular perianth made up of four fused tepals, and one long wiry style. The styles are hooked rather than straight, and are initially trapped inside the upper perianth parts, but break free at anthesis. Seeds are produced in follicles embedded in the woody bases of the flower heads.^[1][2]

Taxonomy

See also: Taxonomy of Banksia

Early collections of B. xylothemelia include a specimen collected in the Dragon Rocks Nature Reserve by Robert M. Buehrig on 9 December 1993, and a specimen collected from west of Lake King by P. G. Wilson. On 11 October 1994, Alex George collected what would later become the type specimen, from a location on the Holt Rock South Road, 14 kilometres north of Newdigate-Lake King Road, at 32°58′S 119°23′E / 32.967°S 119.383°E / -32.967; 119.383.^[3][1]

Two years later, George published a formal description of the species in Nuytsia 10(3), placing it in genus Dryandra, subgenus Dryandra and series Armatae. He gave it the specific name "xylothemelia", from the Greek "xylon" (wood) and "themelios" (foundation), in reference to species' lignotuber, the possession of which distinguishes it from its close relative B. cirsioides;^[3][1][2] thus the full name of the species was for a time Dryandra xylothemelia A.S.George.^[4]

Early in 2007, Austin Mast and Kevin Thiele transferred all Dryandra taxa to Banksia. The current name for this species is therefore Banksia xylothemelia (A.S.George) A.R.Mast & K.R.Thiele. As an interim measure, Mast and Thiele placed all but one Dryandra taxon in Banksia ser. Dryandra.^[5]

Distribution and habitat

Distribution of B. xylothemelia, shown on a map of Western Australia's biogeographic regions.^[6]

It occurs in sand over laterite or in gravelly loam, amongst heath or sometimes mallee woodlands and shrublands. It occurs only within the Esperance Plains and Mallee biogeographic region,^[6] between Kulin, Lake Magenta, Frank Hann National Park and Hyden.^[1][2]

Ecology

See also: Ecology of Banksia

Like most other Proteaceae, B. xylothemelia has proteoid roots, roots with dense clusters of short lateral rootlets that form a mat in the soil just below the leaf litter. These enhance solubilisation of nutrients, thus allowing nutrient uptake in low-nutrient soils such as the phosphorus-deficient native soils of Australia. It has a lignotuber, so is able to resprout after being burned to the ground by bushfire.

It has been given a rating of "Priority Three - Poorly Known Taxa" on Western Australia's Department of Environment and Conservation's Declared Rare and Priority Flora List.^[6]

An assessment of the potential impact of climate change on this species found that its range is likely to contract by half under mild change, and severe change is likely to lead to extinction unless it migrates rapidly into newly habitable areas.^[7]

Cultivation

B. xylothemelia is rarely cultivated. It prefers lateritic and other heavy soils, and tolerates dry conditions and moderate frosts once established. Tony Cavanagh and Margaret Pieroni suggest that it would be best suited to a small garden in a warm sunny area. Seed takes six to seven weeks to germinate; germination rates appear to be quite low, with most reports suggesting success rates of less than 30%.^[2]

References

1. ^ ^{a b c d} George, Alex S. (1999). "Dryandra". In Wilson, Annette. Flora of Australia. 17B: Proteaceae 3: Hakea to Dryandra. CSIRO Publishing / Australian Biological Resources Study. pp. 251–363. ISBN 0-643-06454-0. 
2. ^ ^{a b c d} Cavanagh, Tony and Margaret Pieroni (2006). The Dryandras. Melbourne: Australian Plants Society (SGAP Victoria); Perth: Wildflower Society of Western Australia. ISBN 1-876473-54-1. 
3. ^ ^{a b} George, Alex S. (1996). "New taxa and a new infragenetic classification in Dryandra R.Br. (Proteaceae: Grevilleoideae)". Nuytsia 10 (3): 313–408. 
4. ^ "Dryandra xylothemelia A.S.George". Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government. http://www.anbg.gov.au/cgi-bin/apni?taxon_id=124577. 
5. ^ Mast, Austin R. and Kevin Thiele (2007). "The transfer of Dryandra R.Br. to Banksia L.f. (Proteaceae)". Australian Systematic Botany 20: 63–71. doi:10.1071/SB06016. 
6. ^ ^{a b c} "Dryandra xylothemelia A.S.George". FloraBase. Department of Environment and Conservation, Government of Western Australia. http://florabase.dec.wa.gov.au/browse/profile/16240. 
7. ^ Fitzpatrick, Matthew C.; et al. (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. 

External links

• "Dryandra xylothemelia A.S.George". Flora of Australia Online. Department of the Environment and Heritage, Australian Government. http://www.anbg.gov.au/abrs/online-resources/flora/stddisplay.xsql?pnid=46418. 
• "Dryandra xylothemelia A.S.George". FloraBase. Department of Environment and Conservation, Government of Western Australia. http://florabase.dec.wa.gov.au/browse/profile/16240. 
• "Dryandra xylothemelia A.S.George". Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government. http://www.anbg.gov.au/cgi-bin/apni?taxon_id=124577.