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.
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click here to see geographic restrictions).
The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Lepidium aschersonii
Profile last updated:
03 Jan 2019
Description
Erect perennial herb to 30 cm high, hairy and intricately branched, with the smaller branches spinescent. Plants become woody and more spinose in dry conditions. Basal leaves lobed, to 12 cm long, leaves reducing in size up the stem. Flowers small, borne in elongated clusters terminating in a spine. Fruit a 2-celled, flattened circular pod on a spreading stalk, 4 mm long and 2.5 mm wide, with slight wings in the upper half forming a small notch at the apex. Lepidium aschersonii is distinguished from other Lepidium species by the presence of tiny spines which give the mature plants an intricate appearance.
Distribution
Not widespread, occurring in the marginal central-western slopes and north-western plains regions of NSW (and potentially the south western plains). In the north of the State recent surveys have recorded a number of new sites including Brigalow Nature Reserve, Brigalow State Conservation Area, Leard State Conservation Area and Bobbiwaa State Conservation Area. Also known from the West Wyalong in the south of the State. Records from Barmedman and Temora areas are likely to be no longer present. Approximately 50% of the total Lepidium aschersonii recorded for Australia occurs in NSW.
Habitat and ecology
- Found on ridges of gilgai clays dominated by Brigalow (Acacia harpophylla), Belah (Casuarina cristata), Buloke (Allocasuarina luehmanii) and Grey Box (Eucalyptus microcarpa). In the south has been recorded growing in Bull Mallee (Eucalyptus behriana). Often the understorey is dominated by introduced plants. The species grows as a a component of the ground flora, in grey loamy clays. Vegetation structure varies from open to dense, with sparse grassy understorey and occasional heavy litter.
- Flowers from spring to autumn.
- Plants in the Narrabri population have been observed producing abundant seed, and as the species is believed to be short-lived and large numbers of plants were present at the site, Lepidium aschersonii appears to be successfully reproducing.
- Populations have been known to immediately disappear following inundation by flooding, reappearing several seasons later. An apparent increase in numbers during drought conditions has also been observed. The species is reported to be salt tolerant and also grows well under dry conditions.
- Recorded population sizes vary from 18 to 5000+ plants. Plant numbers decrease with increasing overstorey density, and plants were not found where the Brigalow canopy cover exceeded about 60%. The species is often described as a “weed” where it dominates paddocks.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Invasion and spread of exotic grasses including Coolatai and African love grass.
- Overgrazing by domestic livestock directly impacting plants and causing disturbance, which facilitates the invasion of weeds and causes erosion.
- Habitat fragmentation and loss due to land clearing for fence lines and from grading and bulldozing along roadsides.
- Inappropriate application of pesticides leading to overspray into areas of key habitat where species occurs.
- Altered hydrological regime and soil water levels from past and current activities such as roadworks, farming, paddock levelling and earthworks creating channels and causing changes in the water table.
- Browsing and destruction of plants and habitat by feral pigs and rabbits
- Shrub thickening, e.g. Vachellia farnesiana, due to reduced habitat condition favouring a higher density of shrubs and outcompeting herbaceous species for resources.
- Insufficient understanding of distribution and abundance of the species throughout the South West Slopes. Known records are on unsecure tenure and vulnerable to extirpation.
- Trampling and soil compaction (reduces seedling regeneration).
- Roadworks and rubbish dumping.
- Roadworks - populations potentially at risk from roadworks, firebreak construction, utilities installation and maintenance
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 Spiny Peppercress in New South Wales.
Activities to assist this species
- Protect existing populations from grazing.
- Protect existing populations from stock through appropriate fencing.
- Protect roadside sites from roadworks and dumping.
- Weed control in population areas.
- No further loss of extant populations.
- Report any new occurance of the species to the Department of Environment and Conservation.
- Heavy grazing by rabbits and grazing and soil disturbance by pigs is a known threat to this species.
Information sources
- Briggs, J.D. and Leigh, J.H. (1996) Rare or Threatened Australian Plants. Revised Edition. (CSIRO Publishing, Melbourne)
- Hewson, H.J. (1981) The genus Lepidium L. (Brassicaceae) in Australia. Brunonia 4(2): 217-308.
- Hewson, H.J. (1982) Brassicaceae. 13. Lepidium. Flora of Australia 8: 256-283.
- Leigh, J.H. and Briggs, J.D. (eds.) (1992) Threatened Australian Plants - overview and case studies. (Australian National Parks and Wildlife Service, Canberra)
- Retter, L. and Harden, G.J. (1990) Lepidium. In Harden, G.J. (ed.) Flora of New South Wales. Volume 1. New South Wales University Press, Sydney.
- Smith, L.P. (1994) Status and distribution of Spiny Pepper-Cress Lepidium aschersonii in New South Wales, with references to occurrences elsewhere in Australia (Biosis Research: Melbourne).
- Thellung, A. (1906) Die Gattung Lepidium (L). R. Br. Eine monographische studie. Neue Denkschriften der Allgemeine Schweizerischen Gesellschaft für die Gesamten Naturwissenschaften 41(1): 1-340, p. 310.
- Walsh, N.G. and Entwisle, T.J. (1998) Flora of Victoria; Volume 3, Dicotyledons Winteraceae to Myrtaceae. (Inkata Press, Melbourne)
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