Illawarra Irene - profile

Indicative distribution

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Key:

known

predicted

The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.

Scientific name: Irenepharsus trypherus

Conservation status in NSW: Endangered

Commonwealth status: Endangered

Profile last updated: 21 Mar 2022

Description

The Illawarra Irene is a hairless annual or short-lived perennial herb that grows to 250 cm. It has a spreading to erect habit and is often multi-stemmed. Stem leaves are narrow, toothed and mostly 4 to 8 cm long. Its flowers have four white petals (to 4 mm long) and are borne from the branch tips. The fruit is an upright curved dry pod, 20 mm long and 1 mm wide. Its small seeds (to 1 mm long) become sticky when wet.

Distribution

The species has been recorded from 18 sites within the local government areas of Kiama, Shellharbour, Shoalhaven, Tallaganda, Wingecarribee, and Wollongong. Found at such places as Minnamurra Falls, the Jamberoo area, and Morton and Macquarie Pass National Parks. The species has rarely been collected, perhaps because it looks like a weed.

Habitat and ecology

Typically inhabits steep rocky slopes near cliff lines and ridge tops. The species is less typically found growing out of rock crevices or on narrow benches along cliff lines.
The vast majority of sites are recorded from the upper slopes of the ridge systems that extend south and east of the Illawarra escarpment, although the species has also been recorded from the deep sandstone gorges of the Shoalhaven River.
Associated vegetation includes moist sclerophyll forest, Ironwood Backhousia myrtifolia thicket, and rainforest.
Can survive for up to three years in ideal conditions.
Mature plants are capable of reshooting from dry or desiccated stems following light grazing, trampling, or drought.
The species is thought to be a prolific seeder, with disturbance and light levels influencing germination.
The fire response of the species (and its soil seedbank) is unknown.

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.

Sydney Basin

Threats

Further loss and fragmentation of habitat, particularly through clearing for agriculture.
Habitat degradation resulting from weed invasion and erosion.
Small numbers and a limited distribution put the species at risk of extinction through natural catastrophes or environmental changes.
Goats browsing and destroying individual plants.
Risk of trampling and damage to plants arising from formal and informal access tracks to waterfalls.
Lack of distributional information.
Potential effects of grazing/browsing due to goats and/or deer could be severe, but little is known about impacts.
Disturbance by domestic stock.

Recovery strategies

Priority actions are the specific, practical things that must be done to recover a threatened species, population or ecological community. The Office of Environment and Heritage has identified 24 priority actions to help recover the Illawarra Irene in New South Wales.

Activities to assist this species

Establish an ex-situ collection.
Support and provide information to land managers regarding appropriate management.
Implement goat and feral deer control measures.
Avoid burning habitat that contains the species until its fire response has been determined.
Consider off-site impacts in the assessment of nearby developments.
Prevent inappropriate water run-off entering sites.
Install fencing to exclude livestock and machinery where required.
Undertake weed control in sites where it is necessary.
Protect areas of known and potential habitat from clearing and further fragmentation.
Restore degraded habitat using bush regeneration techniques.
Monitor the known populations for changes in numbers.
Map known sites and conduct searches of potential habitat for new sites.

Information sources

Department of Environment and Conservation (NSW) (2005) Irenepharsus trypherus (Illawarra irene) Recovery Plan. NSW DEC, Sydney.
Harden, G.J. (ed.) (2000) Flora of New South Wales Vol. 1. UNSW Press, Kensington, NSW.

IBRA Bioregion	IBRA Subregion	Known or predicted	Geographic restrictions region

Sydney Basin	Ettrema	Known	None
Sydney Basin	Illawarra	Known	West of Princes Highway
Sydney Basin	Moss Vale	Known	Within 5 km of the escarpment

Images

Irenepharsus trypherus in flower Image 1 of 5.
View slideshow.

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