flowers, foliage

Natural populations

Eremophila glabra is a perennial shrub up to 2 m tall. At present it has a tentative subdivision of subspecies as much more research is needed, especially in Western Australia, to resolve the many taxonomic problems associated with this species [5]. The subspecies currently recognised are [5]:

Subsp. albicans – within this subspecies is a coastal form (in sands) and an inland form (in sandy loams and sandy clays). These two forms differ in leaf form, the size of the stellate hairs, flower colour and in fruit structure; has yellow, orange flowers.

Subsp. carnosa – restricted to coastal sites north from the Geraldton sandplains; has red flowers.

Subsp. chlorella - mainly occurs near Perth. It is endangered due to urban expansion; has green, yellow flowers.

Subsp. elegans – restricted population in south-west Western Australia; has green flowers.

Subsp. glabra - is the most widespread of the subspecies, extending to all mainland states, in a variety of soil and vegetation types. Subsp. glabra occurs in both tetraploid and hexaploid forms but no morphological differences between these polypoid states have been found. One distinct form occurs near Kalgoorlie, with leaves of a smooth, almost silvery white appearance; has red, orange flowers.
Subsp. psammophora – restricted population on the coast and islands in the Carnavon region; has red flowers.
Subsp. murrayana - is widespread throughout the Murray lands in South Australia, and extends into New South Wales and Victoria (flowers are orange-red, yellow).
Subsp. tomentosa - within this subspecies is a coastal form in heath and an inland form in Acacia woodland (including saline environments); has orange, red, brown flowers.
Subsp. verrucosa – restricted inland population in the Murchison region of Western Australia; has yellow flowers.

A distinction is made between coastal and inland forms of subsp. elegans and subsp. tomentosa, with differences in growth form and variations in tolerances to drainage and salinity [pers. comm. Andrew Brown, DEC, Western Australia].

Flowering and seeds

In Western Australia, flowering times in E. glabra are recorded as follows [37]: subsp. albicans – May to November; subsp. carnosa – July to November; subsp. chlorella – July to November; subsp. elegans - August to September; subsp. glabra – January to November; subsp. psammophora – August to December; subsp. tomentosa – April to October; subsp. verrucosa - July to September. Eremophila seed in general has been found to be difficult to germinate by propagators. Plants are generally reproduced from cuttings. The hard woody fruits have physical and chemical inhibitors that delay germination [122]. Seed germination is greatly improved once it is excised from the hard fruit covering [122]. Natural weathering processes of fire, wet and dry seasonal cycling and abrasive soil movement will eventually break down hard fruit coats and stimulate germination [122].

Cultivation and uses

It is readily eaten by stock, especially sheep when other forage is scarce [18]. It is a decreaser species and its presence indicates fair to good condition [18].

Key descriptors:
Subsp. albicans:
Climate parameters
Mean annual rainfall: 350-800 mm
Rainfall distribution pattern: winter
Mean annual temperature: 13-21 °C
Mean max. temperature of the hottest month: 28-35 °C
Mean min. temperature of the coldest month: 4-6 °C
Frosts (approx. no. per year): greater than 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: metres 0-450 metres
Soil factors
Texture: loam, sandy loam, sandy clay loam or sand
Subsp. carnosa:
Climate parameters
Mean annual rainfall: 250-450 mm
Rainfall distribution pattern: winter
Mean annual temperature: 14-26 °C
Mean max. temperature of the hottest month: 30-33 °C
Mean min. temperature of the coldest month: 9-12 °C
Frosts (approx. no. per year): greater than 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: 0-30 metres
Soil factors
Texture: sand
Subsp. elegans:
Climate parameters
Mean annual rainfall: 350-650 mm
Rainfall distribution pattern: winter
Mean annual temperature: 15-21 °C
Mean max. temperature of the hottest month: 30-35 °C
Mean min. temperature of the coldest month: 4-6 °C
Frosts (approx. no. per year): greater than 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: 250-350 metres
Soil factors
Texture: clay loam or loam, sandy loam, sandy clay loam
Subsp. glabra:
Climate parameters
Mean annual rainfall: 150-550 mm
Rainfall distribution pattern: summer, uniform or winter
Mean annual temperature: 10-24 °C
Mean max. temperature of the hottest month: 25-37 °C
Mean min. temperature of the coldest month: 3-7 °C
Frosts (approx. no. per year): greater than 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: 0-600 metres
Soil factors
Texture: loam, sandy loam, sandy clay loam or sand
Subsp. psammophora:
Climate parameters
Mean annual rainfall: 250-300 mm
Mean annual temperature: 17-30 °C
Mean max. temperature of the hottest month: 35-37 °C
Mean min. temperature of the coldest month: 11-13 °C
Frosts (approx. no. per year): frost free or more or less frost free
Altitude: 0-0 metres
Soil factors
Texture: loam, sandy loam, sandy clay loam
Subsp. murrayana:
Climate parameters
Mean annual rainfall: 250-350 mm
Rainfall distribution pattern: winter
Mean annual temperature: 9-24 °C
Mean max. temperature of the hottest month: 30-31 °C
Mean min. temperature of the coldest month: 3-5 °C
Frosts (approx. no. per year): greater than 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: 50-100 metres
Soil factors
Texture: clay loam, loam, sandy loam, sandy clay loam or sand
Subsp. tomentosa:
Climate parameters
Mean annual rainfall: 200-300 mm
Rainfall distribution pattern: winter
Mean annual temperature: 15-28 °C
Mean max. temperature of the hottest month: 30-38 °C
Mean min. temperature of the coldest month: 5-11 °C
Frosts (approx. no. per year): greater than 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: 0-550 metres
Tolerance of extremes in climate
Frost: tolerates frosts in the 0° to -5°C range
Wind: tolerates salt-laden coastal winds
Soil factors
Texture: loam, sandy loam, sandy clay loam
Salinity: slightly to moderately saline
Biological traits under cultivation
Longevity: short-lived less than 15 years
Root system: shallow and spreading
Subsp. verrucosa:
Climate parameters
Mean annual rainfall: 200-300 mm
Rainfall distribution pattern: winter
Mean annual temperature: 13-27 °C
Mean max. temperature of the hottest month: 34-36 °C
Mean min. temperature of the coldest month: 5-6 °C
Frosts (approx. no. per year): greater than 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: 300-400 metres

References

[5] Chinnock RG (2007) Eremophila and Allied Genera: a monograph of the plant family Myoporaceae. The Botanic Gardens and State Herbarium, Department of Environment & Heritage, Government ofSouth Australia.

[18] Mitchell A, Wilcox D (1994) Arid shrubland plants of Western Australia. University of Western Australia Press, Perth.

[37] Paczkowska G, Chapman AR (2000) The Western Australian Flora - A Descriptive Catalogue. Publishers: Wildflower Society of Western Australia, Western Australian Herbarium, CALM and the Botanic Gardens and Parks Authority,Western Australia.

[122] Cochrane A (2002) Seed notes for Western Australia: Eremophila. 4p Pamphlet No. 5, Wildflower Society of Western Australia, Perth Branch, Nedlands

Internet links

Australian Society for Growing Australian Plants – species profile: http://asgap.org.au/e-glab.html

FloraBase Western Australia Flora Online – species description & distribution: http://florabase.calm.wa.gov.au/browse/profile/7215 [search site for information on subspecies]

PlantNet NSW Flora Online – species description & distribution: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Eremophila~glabra

South Australia Flora Online – species description & distribution: http://www.flora.sa.gov.au/cgi-bin/texhtml.cgi?form=speciesfacts&family=Myoporaceae&genus=Eremophila&species=glabra

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