Eremophila ionantha - Violet-flowered Eremophila

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Eremophila ionantha - Violet-flowered Eremophila

This species prefers the more arid woodland zones from Esperance to the Kalgoorlie region, where it tends to be more common.  It prefers to grow in the heavier soils and can reach 2 metres in height, but local colonies seen were little more than half that size.  The flowers too in the Lake Tay to the Peak Charles area are quite pale when compared to some violet forms that gave it the common name of the Violet-flowered Eremophila.

Generally E. ionantha is an open upright shrub and only eye-catching when in flower (anytime between September to February), otherwise blending into surrounding vegetation.  Like many Eremophila species, they appear in numbers shortly after bushfires, but die back after a few years as taller plants begin to dominate.

The Eremophila genus belongs to the Scrophulariaceae family, but may also be listed by some authorities under Myoporaceae.

My thanks to the WA Herbarium for identification.

Eremophila alternifolia – Broad-leaf Form

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Eremophila alternifolia – Broad-leaf Form

Aboriginals had many uses for this plant and dried foliage was commonly carried with them for medical and/or ceremonial occasions. Medically it was used as an antiseptic and to alleviate pain and fever; the foliage contains verbascoside, which is antibacterial, an antioxidant and has analgesic effects. It also dilates blood vessels to reduce blood pressure and apparently helps to induce sleep and promote general well-being (1).

Another possible reason for this species widespread use is its exceptionally large distribution, fanning from the Meekatharra region (mid NW of WA) to Central Australia (NT) and to the Nullarbor, then through SA into the outback of NSW, so would have been available to many Aboriginal groups.

Being so widespread Eremophila alternifolia is highly variable especially in regards to foliage, with most inland forms having linear-subterete foliage to 4 cm (over 1 5/8”) in length, whereas populations on its southern boundary are more like those above, being much broader and shorter (2 1/2 cm or 1” in length).

The flowers also vary, with some having pronounced spots on the outside of the flower, whilst some have none; the colour can be red, pink or cream. However they do not vary in the shape of the broad recurved lower petal, which apart from a narrow pointed tip, is truncated at the end. The sepals are glabrous (without hairs) and have many small veins (better seen on dry specimens).

Some shrubs of Eremophila alternifolia have been recorded growing to 5 metres (16’) in height, although locally they rarely exceed half that size. They are not common in the Esperance region and only occur in the northeastern sector, where they favour the edges of open plains, growing in a red loam over a crumbly a limestone substrate that permits deep root development.

The open plains have a similar soil, but overlie a very hard limestone where silica has been dissolved by water movement (sometimes hydrothermal) and reformed to produce a calcrete, which is a very hard cemented material that roots cannot penetrate. Another local similarity is the limestone/calcrete overlies or abuts low-lying granite outcrops, which is evident in the habitat photo by the distant red blossom.

The Eremophila genus is the major potion of the Scrophulariaceae family (synonymous Myoporaceae).

Reference:

(1). Indigenous Knowledge and Pharmaceuticals by M Pennacchio and E L Ghisalberti.

(2). Eremophila and allied genera by RJ Chinnock.

Eremophila ciliata – Emu Bush

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Eremophila ciliata – Emu Bush

This species discovered 22 years ago on a remote large rocky outcrop to the NE of Esperance, is now ‘Declared Rare Flora.’ Since then there have been less than a handful of collections and possibly all from the original colony, which currently contains 200-300 plants in a 50 x 5 metres (55 x 5-6 yard) strip of shallow sandy loam (with rocks) over granite; it is an unusual habitat not common to this region.

On the rocky outcrop in question, there are a couple of drainage gullies running across the main slope which catch most of the rainwater run-off and redirects it at a near 90 degree angle. However with heavy rainfall this gully would overflow and the excess water continue downhill on its original course. It is on this east facing overflow section, where Eremophila ciliata is found.

The cross-cutting drainage channels have over eons filled with small eroded boulders, rock and soil, which after the usual winter/spring rains become a moist habitat supporting many plant species. The plants in this unusually good habitat are congested and battle for growing space, a situation not suitable for most Eremophila spp. that would be quickly smothered. However, in the shallow and less watered soil on the far side of this channel, it provides habitat for a few hardy species like Eremophila ciliata that are ideally suited to the semi-arid conditions of the region.

In these drier situations plants tend to be smaller and more widely spaced, thereby permitting slower growing species like this Eremophila to thrive. A bushfire had passed through this area 3-4 year earlier and the E. ciliata plants above had germinated and grown to around ½ metre (20”) in height since. The other (less deep) north/south drainage channel some 100 metres (110 yards) above, was not burnt by the fire and a single untidy Eremophila ciliata plant (2 metres or over 6’ in height) survives. In this location no juveniles were evident, indicating this species like many Eremophila spp. benefit from periodic bushfires to clear large vegetation and stimulate seed germination.

Eremophila ciliata is named after the long fine hairs around the edge of the calyx lobes (base of flowers). These flowers are insect pollinated and quite small, being less than 1 cm (3/8”) in length, but are attractively coloured lilac, blue or purple. The underside of the leaves and stems are prominently covered in round tubercles, whilst the upper leaf surface is hairless and smooth. The most common flowering period would be August and September, but like many of these semi-arid species, they are very opportunistic and will produce blossom after good rain at other times.

The Eremophila genus belongs to the Scrophulariaceae family, but may also be listed by some authorities under Myoporaceae.

Eremophila glabra subsp. albicans - Emu Bush

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Eremophila glabra subsp. albicans - Emu Bush

Eremophila glabra subsp. albicans would be the most common subspecies of Eremophila glabra to be found in the Esperance region. However, there are many other prominent forms that are currently divided into 9 subspecies, 7 of which are endemic to Western Australia with subsp. glabra occurring Australia wide and subsp. murrayana endemic to the Murray district of SA, NSW and Victoria, plus there are many undescribed subspecies that await study.

I encountered one of these subspecies that I thought was E. glabra subsp. tomentosa, but on comparison with a more typical form of subsp. albicans, it appears to be more closely associated with it despite being thickly covered in matted hairs like subsp. tomentosa. The shape of the foliage and largely hidden calyx (under matted hairs) would however suggest this correction. Nevertheless, it does illustrate the variability of some widely distributed species.

The photographs with the letter A, are of the more typical E. glabra subsp. albicans, which is quite common off Cascades Road along a 10 kilometre (6 mile) stretch, SE of Cascades (almost 90 km or 55 miles NW of Esperance). Photos with the letter B are from a colony 140 km (85 miles) NE of Esperance. Both colonies were growing in a sandy loam over limestone.

Besides the hair cover difference of each group, colony A was a spreading shrub to 60 cm x 1.5 metre diameter (2’x 5’), whilst colony B was upright to 1.2 metres in height x 1 metre in width (4’x 3’). Interestingly upon further investigation, the average annual rainfall of colony B is half the amount colony A receives (20-30 cm or 8”-12” for B) to (40-50 cm for A); the average annual temperature is similar for both colonies. Therefore the covering of extra thick matted hair would aid the development of a microclimate, presumably to reduce moisture loss.

Eremophila glabra subsp. albicans is recorded from Carnarvon to Bunbury and from Albany to the Nullarbor, with colonies extending inland to the Kalgoorlie region, so very widespread and indicating there are probably other variations too. Eremophila glabra despite its many forms is also similar to another common, widespread and highly variable species Eremophila decipiens. However they are easily separated by the pedicel (flower stalk), with E. decipiens being at least twice as long as its longest sepal and curved into an S shape, whilst all forms of E. glabra have a straight pedicel much the same length as the largest sepal.

The flowers are bird-attracting and depending on local rainfall bloom anytime from May to November, although locally spring would be the main period.

Eremophila glabra is a member of the Scrophulariaceae family, but may still be listed under Myoporaceae elsewhere.

Eremophila scoparia - Broom Bush

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Eremophila scoparia - Broom Bush

This broom-like shrub is also known as the Silver Emu-bush or Scotia Bush and is found across southern Australia in WA, SA, NSW and Victoria, although with the latter two, only in their western portion. In WA it is found inland from Southern Cross to north of Kalgoorlie, then across the Nullarbor including some coastal areas. Around Esperance it is mainly encountered in mallee country to the North and NE of the town, where it favours shallow soils over limestone that often contain a high portion of powdered limestone.

Locally Eremophila scoparia grows to around 2 metres (6’-7’) in height, but can reach 3 metres elsewhere. The stems and foliage are covered in small silver/grey scales to give the plant an attractive silvery hue, which is enhanced by the leaves that are in pairs, each with a recurved point that face away from each other. The mauve/purple or lilac flowers can with some forms grow to 2.5 cm (1”) in length, but around Esperance are mostly half that size, although they can occur in considerable numbers.

As the shrub naturally grows in low rainfall areas with irregular rainfall, it has developed a strategy to produce flowers in response to out-of-season passing storms. In good seasons it can usually be found in bloom at anytime of the year, but late winter and during spring when temperatures are pleasantly warm and on average with reasonable rainfall, they are at their best.

Eremophila lactea - Milky Emu Bush

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Eremophila lactea - Milky Emu Bush

The Eremophila or Emu Bushes were contained within the Myoporaceae family, but in WA and elsewhere, have now been placed into Scrophulariaceae. There are a great many Eremophila species (in excess of 200), with the vast majority found in Western Australia and most of these occurring in remote regions so consequently are not endangered. However for those species closer to human occupation and clearing due to farming activities, this is not necessarily the situation.

Eremophila lactea is gazetted Declared Rare Flora, which means it is regarded as threatened flora that is endangered and vulnerable. It is known only from small roadside locations west of Grasspatch 70 km (45 miles) WNW of Esperance, which is surrounded by cleared farmland (broad-acre wheat growing area), fortunately it is a low rainfall region therefore weed growth is not a problem. Soils are typical for mallee environments, being a fine sand/clay loam over limestone.

When I was there in 2011, I saw around 20 plants on both sides of the road, but considerably more had died leaving only leafless skeletons. Most live plants were growing in road drainage channels and the inside curve of the road where large trees/shrubs were set further back and where roadside drainage would collect. This suggests to me that the mature mallee eucalypts and/or large Melaleuca shrubs are taking most of the moisture and in dry periods any Eremophila lactea growing within their root zone are unlikely to survive.

Shrubs growing under mature mallee are usually short-lived, but do very well for several years after a bushfire and before the Eucalyptus/large shrubs begin to dominate. Another indication of this situation is the spindly upright growth, which was the case with most plants seen; the only bushier ones were growing away from the larger vegetation and in a drainage zone.

The tallest shrubs were around 2.5 metres (8’) in height, but have been noted growing a metre taller; branches were distinctly upright, but a weeping habit apparently develops with age. The species name of Eremophila lactea is taken from a white milky substance deposited on the leaves and stems. Flowers are a little under 1.5 cm (1/2”) in length and are recorded in bloom from September to November.

Reference: Nuytsia – Vol.5 – No.3 - 1986.