Indicative distribution
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: Asterolasia elegans
Profile last updated:
13 Nov 2024
Description
A tall, thin shrub to 3 m high. Leaves are lance-shaped, 4 - 13 cm long, with rusty, star-shaped hairs on both surfaces. Flowers (in spring) are large and prominent, having white petals 8 - 14 mm long with dense, white, star-shaped hairs on the outside surface.
Distribution
Occurs north of Sydney, in the Baulkham Hills, Hawkesbury and Hornsby local government areas. Also likely to occur in the western part of Gosford local government area. Known from only seven populations, only one of which is wholly within a conservation reserve.
Habitat and ecology
- Occurs on Hawkesbury sandstone.
- Found in sheltered forests on mid- to lower slopes and valleys, e.g. in or adjacent to gullies which support sheltered forest. The canopy at known sites includes Turpentine (Syncarpia glomulifera subsp. glomulifera), Smooth-barked Apple (Angophora costata), Sydney Peppermint (Eucalyptus piperita), Forest Oak (Allocasuarina torulosa) and Christmas Bush (Ceratopetalum gummiferum).
- Ecological knowledge about this species is very limited.
- The species is considered to be fire sensitive and reliant on seed germination after disturbance to maintain populations. A soil seedbank appears to be established by this species, so for a number of years following fire or other disturbance the species may not be apparent, but be present only as seed in the soil.
- The size of the seedbank depends not only on the amount of seed contributed by mature plants each season, but on the level of dormancy of the seed which can vary from year to year. The longevity of each crop of seed in the soil is probably relatively short (perhaps 5 - 10 years).
- Either heat or smoke or a combination of these factors may play a role in breaking soil-stored seed dormancy. Both the amount of smoke and the level of heating could influence germination success. A certain level of heat may be optimal for breaking seed dormancy (such that too little heat results in seeds staying dormant, while too much heat kills seeds).
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- The main threat is likely to be that of a frequent fire regime. If the fire interval is shorter than the period between germination and seed production, recruitment to the soil-stored seedbank will be limited or not occur at all and post-fire regeneration will deplete the existing seedbank. Three or more fires in close succession may therefore result in population decline or extinction.
- Sustained high frequency fire can also lead to a reduction in vegetation structure and subsequent changes in microclimate, affecting the suitability of the habitat for the species which appears to require moister, sheltered aspects.
- Fires of an inappropriate intensity that fail to break soil-stored seed dormancy (too cool) or kill soil-stored seed (too hot) may lead to population decline.
- Fragmentation and direct loss of habitat may occur as a result of native vegetation clearing or modification for semi-rural and urban expansion and agricultural development.
- Road use and management, including mechanical methods for roadside vegetation management or bushfire fuel hazard reduction, where populations are proximate to roads, utilities and other assets.
- As it often occurs in areas of Hawkesbury sandstone outcrops, legal or illegal bush rock removal in such areas may destroy plants and degrade the habitat of the species.
- Rubbish dumping.
- Grazing by domestic stock or feral animals may impact directly, or lead to degradation of vegetation structure and floristics though trampling, erosion and the spread of weeds.
- Weed invasion.
- May be adversely affected by changes to habitat or fire regimes caused by climate changes resulting from or accelerated by human activities. The species' restricted distribution and fragmented populations means it may be especially susceptible to reductions in the bioclimatic range caused by climate change.
- Minimise pollution and run-off from sewage treatment plants/stormwater that facilitates weed invasion and growth.
- Lack of knowledge of the species distribution and threats.
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
18 priority actions
to help recover the Asterolasia elegans in New South Wales.
Activities to assist this species
- Prevent frequent fires from impacting on the populations.
- At appropriate intervals, fires of moderate to high intensity or fires of low intensity that move slowly and fully combust a high proportion of ground fuels should be planned and implemented to generate a level of heat to break seed dormancy.
- Preparation of site-specific fire management plans.
- Ensure that road and track maintenance and construction and weed control activities are planned and implemented to take account of the presence of the species and to avoid damaging individual plants or degrading habitat for the species.
- Minimise habitat loss, fragmentation or disturbance by retaining native vegetation containing the species and maintaining connectivity between populations.
- Remove rubbish and inhibit further dumping.
- Seek conservation agreements with land owners.
- Further research into the demography and reproductive ecology of the species, so that appropriate fire-free intervals and other guidelines for fire management can be determined.
- Survey potential habitat for new populations.
Information sources
- Auld, T.D. (2001) The ecology of the Rutaceae in the Sydney region of south-eastern Australia: poorly known ecology of a neglected family. Cunninghamia 7(2): 213-239
- Auld, T.D., Keith, D.A. and Bradstock, R.A. (2000) Patterns in longevity of soil seedbanks in fire-prone communities of south-eastern Australia. Australian Journal of Botany 48(4):, 539-548
- Bell, S.A.J. (2008) Rare or threatened vascular plant species of Wollemi National Park, central eastern New South Wales. Cunninghamia 10(3): 331–371
- Benson, D. and McDougall, L. (2001) Ecology of Sydney plant species. Part 8: Dicotyledon families Rutaceae to Zygophyllaceae. Cunninghamia 7(2): 241-462
- Fairley, A. (2004) Seldom seen: rare plants of greater Sydney. (Reed New Holland, Sydney)
- Harden, G.J. and Mole, B.J. (2002) Asterolasia. Pp. 310-3 in Harden, G.J. (ed.) Flora of New South Wales. Volume 2 Revised Edition. (University of New South wales Press Ltd., Sydney)
- McDougall, L. and Porteners, M. F. (1990) Asterolsia elegans (Rutaceae), a new species from the Sydney region. Telopea 4(1): 139-140
- Office of Environment and Heritage (NSW) (2011) National Recovery Plan for Asterolasia elegans. (OEH (NSW), Sydney)
- Scott, J. (1994) Conservation research statement for Asterolasia elegans. Australian Nature Conservation Agency, Endangered Species Program Project No. 297. Unpublished.
- Scott, J. (1994) Recovery plan for Asterolasia elegans. Australian Nature Conservation Agency, Endangered Species Program Project No. 297. Unpublished.
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