Eremophila polyclada, commonly known as twiggy emu-bush, flowering lignum, lignum fuchsia and desert lignum is a plant in the figwort family Scrophulariaceae and is endemic to Australia. It is a dense, spreading shrub with narrow leaves and white to pale lilac-coloured, purple-spotted flowers. It occurs in all mainland states except Western Australia.
| Twiggy emu-bush | |
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Lamiales |
| Family: | Scrophulariaceae |
| Genus: | Eremophila |
| Species: | E. polyclada
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| Binomial name | |
| Eremophila polyclada | |
| Synonyms[1] | |
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Description
editEremophila polyclada is a dense, spreading shrub which grows to a height of 1–3 m (3–10 ft) and a width of 1–5 m (3–20 ft). Its branches diverge at about 90° to each other and are stiff, often with a spine at the end. The leaves are arranged alternately along the branches and are linear in shape, mostly 20–40 mm (0.8–2 in) long, 1–3 mm (0.04–0.1 in) wide and are often sticky when young due to the presence of resin.[2][3][4][5]
The flowers are borne singly or in pairs in leaf axils on a stalk 1–2.5 mm (0.04–0.1 in) long. There are 5 green, overlapping sepals which are egg-shaped, have a prominent keel, thin, wing-like edges and are mostly 4.5–7 mm (0.2–0.3 in) long. The petals are 20–35 mm (0.8–1 in) long, joined at their bases to form a tube. The petal tube is white to very pale whitish-lilac and has faint blackish to green purple spots on the inside of the lobes and purple spots inside the tube. The tube and petal lobes are glabrous except that the middle part of the lowest lobe and the inside of the tube are hairy. The 4 stamens are fully enclosed in the tube. Flowers appear between October and May and are followed by fruits which are oval-shaped, cone-shaped or elliptical with a pointed and are 8.5–13 mm (0.3–0.5 in) long.[2][3][4][5]
Taxonomy and naming
editThe species was first formally described by Ferdinand von Mueller in 1855 as Pholidia polyclada.[6] The description was published in Journal of an Expedition into the Interior of Tropical Australia.[7] In 1860 Mueller changed the name to Eremophila polyclada.[8][9] The specific epithet (polyclada) is derived from the ancient Greek words polys (πολύς), meaning "many" and klados (κλάδος) meaning "twig".[10]
Distribution
editEremophila polyclada is widespread in New South Wales to the west of Lightning Ridge[3] and in southern Queensland. It is also found in a few places along the Murray River in Victoria and South Australia. There is one record from Tarlton Downs in the Northern Territory. It grows in sandy to clay loam soils often on floodplains and other low-lying areas.[2][3]
Use in horticulture
editTwiggy emu-bush is an ornamental shrub which is well known in horticulture, and some specimens have been grown for more than 35 years. It flowers profusely in summer, bearing masses of white flowers when most other shrubs are dormant and is a useful screening plant, with its dense, tangled branches. Propagation is easiest from cuttings which strike within a few weeks in warm weather and its arching branches sometimes develop roots when they touch the ground. A very drought tolerant shrub, it only requires watering once or twice during a long drought and a deep watering early in summer will sometimes stimulate a mass flowering. It is also tolerant of frost and can be pruned, preferably in early autumn.[11][12] A hybrid with E. divaricata called Eremophila 'summertime blue'[13] is popular in American gardens.[14][15][16]
References
edit- ^ a b "Eremophila polyclada". Australian Plant Census. Retrieved 6 September 2020.
- ^ a b c Chinnock, R.J. (Bob) (2007). Eremophila and allied genera : a monograph of the plant family Myoporaceae (1st ed.). Dural, NSW: Rosenberg. pp. 434–435. ISBN 9781877058165.
- ^ a b c d Chinnock, Robert J. "Eremophila polyclada". Royal Botanic Garden Sydney: Plantnet. Retrieved 29 February 2016.
- ^ a b "Eremophila polyclada". State Herbarium of South Australia; eflora. Retrieved 29 February 2016.
- ^ a b "Eremophila polyclada". Lucid Central Keys. Retrieved 29 February 2016.
- ^ "Pholidia polyclada". APNI. Retrieved 29 February 2016.
- ^ von Mueller, Ferdinand (1855). Definition of rare or hitherto undescribed Australian plants. Melbourne: Goodhugh and Trembath. pp. 14–15. Retrieved 29 February 2016.
- ^ "Eremophila polyclada". APNI. Retrieved 29 February 2016.
- ^ von Mueller, Ferdinand (1860). "On the genus Eremophila". Papers and Proceedings of the Royal Society of van Diemen's Land. 3 (2): 294. Retrieved 1 March 2016.
- ^ Backer, C.A. (1936). Verklarend woordenboek der wetenschappelijke namen van de in Nederland en Nederlandsch-Indië in het wild groeiende en in tuinen en parken gekweekte varens en hoogere planten (Edition Nicoline van der Sijs).
- ^ Boschen, Norma; Goods, Maree; Wait, Russell (2008). Australia's eremophilas : changing gardens for a changing climate. Melbourne: Bloomings Books. pp. 147–148. ISBN 9781876473655.
- ^ "Eremophila polyclada". Alice Springs Land Council. Retrieved 1 March 2016.
- ^ "Eremophila 'summertime blue'". Australian Cultivar Registration Authority. Retrieved 1 March 2016.
- ^ Chinnock, R.J. (Bob) (2007). Eremophila and allied genera : a monograph of the plant family Myoporaceae (1st ed.). Dural, NSW: Rosenberg. p. 79. ISBN 9781877058165.
- ^ "Eremophila 'summertime blue'" (PDF). Mountain States Wholesale Nursery. Retrieved 1 March 2016.
- ^ Martin, Chris A. "Eremophila polyclada x divaricata 'Summertime Blue'". Arizona State University. Retrieved 1 March 2016.