Threatened Species Translocation Plan

Button Wrinklewort (Rutidosis leptorrhynchoides)

Summary

Button wrinklewort Rutidosis leptorrhynchoides is a perennial wildflower that grows in grasslands and woodlands in Victoria, NSW and the ACT. There are only 29 known extant populations of the species left and only 8 that contain 5000 or more plants. The species is listed as endangered both nationally (EPBC Act 1999) and locally (Nature Conservation Act 2014). Increasing the number of populations through the establishment of new, self-sustaining populations is identified as a key management objective for the preservation of R. leptorrhynchoides in perpetuity in the wild (ACT Government 2017).

The translocation will be undertaken at the Barrer Hill restoration area (Molonglo River Reserve, ACT). The restoration area supports potentially suitable habitat, is within the species known range and is believed to have supported R. leptorrhynchoides in the past. Furthermore, the Molonglo River Reserve is recognised as a biodiversity offset with significant and ongoing funding committed to the restoration, protection and ongoing management of reserve.

Objectives To establish a new, self-sustaining, genetically diverse population of Rutidosis leptorrhynchoides within the Molonglo River Reserve that is capable of surviving in both the short and long term.

Proponents  Parks and Conservation Service (PCS) and Conservation Research (CR), Environment and Planning Directorate (EPD).

 Australian National Botanic Gardens (ANBG)

 Greening Australia (GA)

Translocation team  Richard Milner – Ecologist (PCS)

 Greg Baines – Senior vegetation ecologist (CR)

 Emma Cook – Vegetation ecologist (CR)

 David Taylor (ANBG)

 Martin Henery (ANBG)

 Nicki Taws (GA)

Background Description

The Button Wrinklewort Rutidosis leptorrhynchoides (Figure 1) is an erect perennial forb from the daisy family (Asteraceae). In spring and summer it produces multiple flowering stems 20-35 cm tall. The species is slow growing and dies back to the woody rootstock in late summer or autumn. A new basal rosette of upright leaves appears in early winter, and new stems arise from buds at the soil surface.

Figure 1. Button Wrinklewort Rutidosis leptorrhynchoides Distribution

Rutidosis leptorrhynchoides appears to have been formerly widespread in south-eastern Australia, with disjunct populations in New South Wales and on grassy plains in Victoria. In south-eastern NSW and the ACT it occurs from Michelago and Canberra/Queanbeyan districts to the Goulburn area, and also across the western plains of Victoria. Herbarium records show a reduction in the number and size of R. leptorrhynchoides populations as its grassland and woodland habitat was converted to grazing (Scarlett and Parsons 1990).

Nationally, there are 29 known extant populations occupying a total of about 13.4 ha, with a further 11 populations having become extinct in recent times. Many populations have fewer than ten plants, and only eight contain 5000 or more plants (NSW OEH 2012). Some are restricted to small, scattered refugia that have escaped grazing, ploughing and the application of fertilisers, which include road margins, railway easements and cemeteries (Young 1997), and larger populations occur in grasslands and woodlands on partially modified and lightly grazed land, including a travelling stock reserve and sites on Department of Defence land.

In the ACT region, R. leptorrhynchoides occurs at 11 sites. These are in the suburbs (Barton, Kingston, Yarralumla, Red Hill) just south of Lake Burley Griffin, in the Majura Valley, in the Jerrabomberra Valley (ACT and NSW), and at Crace Nature Reserve in Belconnen (Map 1). The largest populations are in woodland at Stirling Park, Barton (about 49,000 plants) and in grassland at the Defence-owned Majura Training Area (about 27,000 plants) (NSW OEH 2012). The ACT Jerrabomberra/Fyshwick sites are small and fragmented, but are adjacent to larger NSW populations at Queanbeyan Nature Reserve and nearby on ‘The Poplars’ (rural property).

There are large populations in Red Hill Nature Reserve (>3000 plants) and in Crace Grassland Reserve (about 5000 plants), whereas the other ACT sites contain 80 to 2000 plants. The species appears to have been lost from two small sites in recent years.

Conservation Status

Rutidosis leptorrhynchoides is recognised as a threatened species in the following sources:

National Endangered - ANZECC Endangered Flora Network (1998). Endangered - ROTAP (1996). Endangered - Part 1, Schedule 1 of the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) Endangered Species Protection Act 1992 (Commonwealth).

Australian Capital Territory Endangered - Section 91 of the Nature Conservation Act 2014. Special Protection Status Species - Section 109 of the Nature Conservation Act 2014.

New South Wales Endangered - Part 1, Schedule 1 of the Threatened Species Conservation Act 1995.

Victoria. Threatened taxon - Schedule 2 of the Flora and Fauna Guarantee Act 1988.

Threats

The species is at risk from habitat loss throughout its range due to agricultural and urban development. Stirling Park is a possible future site for a new Prime Minister’s residence and Tennant Street Fyshwick could be affected by future expansion of the industrial area. Small sites are more vulnerable to incidental damage associated with human activity, such as roadside maintenance, dumping of waste, inappropriate mowing and parking of vehicles.

Weed invasion poses a risk at many sites. On formerly grazed sites agricultural weeds are of most concern, and small sites can be invaded by weeds that thrive in disturbed areas. Woodland sites are also vulnerable to invasion by woody weeds.

Competition with other understorey vegetation presents a disadvantage to the species at some sites. In Victoria, "intermittent" burning of some grassland communities is recommended to maintain floristic diversity (McDougall 1987, Lunt 1990), but whether burning is advantageous to ACT populations of the species is inconclusive at this stage.

Shading and competition from eucalypt and shrub regeneration is a threat at woodland sites such as Stirling Park and Red Hill.

The species disappears under heavy grazing because it is palatable to stock, though there is some evidence to suggest that intermittent grazing in late summer may not be detrimental. Some of the larger surviving national populations had a prior history of sheep rather than cattle grazing, suggesting that light to moderate sheep grazing may not be detrimental whereas cattle grazing may be (NSW OEH 2012).

Erosion of genetic diversity and increased inbreeding may compromise both short and long-term population viability by reducing individual fitness and limiting the gene pool on which selection can act in the future. This applies to populations of fewer than 200 plants.

More frequent drought in south-eastern Australia is one of the predicted effects of climate change. This may adversely affect some R. leptorrhynchoides populations, particularly through reduced germinant survival due to dry conditions and/or increasing intervals between rain events.

Biology and Ecology

In the ACT, R. leptorrhynchoides occurs on the margins of stands of Yellow Box/Red Gum Grassy Woodland with a ground layer of various native grasses and other forbs, in secondary grasslands derived from that community, and in Natural Temperate Grassland. Soils are usually shallow stony red-brown clay loams. Apple Box (Eucalyptus bridgesiana) is also occasionally present at sites. R. leptorrhynchoides prefers an open habitat and is a poor competitor amongst tall, dense sward-forming grasses. It is found where the soil is too shallow to support the growth of plants that may rapidly overtop it and on deeper soils where the vegetation is kept short by regular disturbance (Scarlett and Parsons 1990). It may also be adapted to the sparser growth of Themeda grass found under trees in woodlands (Morgan 1995a). In Victoria, intermittent burning is prescribed to maintain floristic diversity and habitat structure at some R. leptorrhynchoides sites (DSE 2003). In NSW and the ACT maintenance of habitat structure appears to be less dependent on burning, possibly because poorer soils and/or competition from trees restricts groundcover density and maintains inter-tussock spaces (Morgan 1997, NSW OEH 2012).

Rutidosis leptorrhynchoides flowers between December and April in the ACT. The florets are insect- pollinated, and most of the wind-dispersed seed falls within one metre of the parent plant (Morgan 1995a, 1995b; Wells and Young 2002). The scales at the top of the fruit could facilitate wider dispersal by vertebrates (Scarlett and Parsons 1990). The seeds are short-lived in the soil, so recruitment depends on seeds from the previous year and therefore on the survival and reproductive success of the standing population (Morgan, 1995a, 1995b).

Seeds germinate after autumn rains, and seedling mortality is usually high. In Victoria recruitment may be limited by high summer mortality of seedlings in open microsites and by deep shading in dense, unburnt grasslands (Morgan 1995b, 1997). Studies of germination under field conditions showed that emergence was greatest in larger intertussock gaps (30-100 cm), and seedling survival was greatest in the largest gaps (100cm). R. leptorrhynchoides grows slowly and few or no seedlings flower in their first year (Morgan 1995b, 1997). Time from recruitment to first flowering is usually two or three years (ACT Government 1998; Young et al. 2000b). Established plants are believed to live longer than 10 years under field conditions (Scarlett and Parsons 1990).

There are two main chromosomal races of R. leptorrhynchoides. All populations in the ACT and NSW that have been tested are diploid, though both diploid and tetraploid populations occur in Victoria (Murray and Young 2001, NSW OEH 2012). The species has a sporophytic self-incompatibility mechanism that prevents self-pollination or crosses between related plants that share self-incompatibility alleles. Self-crosses of R. leptorrhynchoides generally result in no fruit, and crosses between unrelated plants produce up to twice as many fruits as those between plants which share one parent (Young et al 2000a). Self-incompatibility systems function to prevent inbreeding and are an advantage in large, genetically diverse populations, but decreasing population size can reduce the number of self-incompatibility alleles leading to a reduction in mate availability and reduced fertilisation success. This has been demonstrated in laboratory and field studies of plants from R. leptorrhynchoides populations of varying sizes (Pickup and Young 2008, Young and Pickup 2010).

Seed set appears to be influenced by population density, with sparsely distributed plants producing less seed than plants in denser groups, in both natural and planted populations of various sizes (Morgan 1995a, Morgan and Scacco 2006). This may reflect the presence of fewer pollinators or less pollen being picked up and transferred among sparsely distributed plants. Other research has shown reduced seed set in small populations (<200 plants) compared to large populations (>1000 plants), despite the maintenance of pollinator service as measured by the number of pollen grains deposited on open-pollinated stigmas (Young and Pickup 2010).

Research into the genetics and demographics of R. leptorrhynchoides has led to the development of a computer model that can be used to predict population trends and the effects of changes in demographic parameters. The model shows that there is a clear relationship between the amount of genetic diversity in a population and how quickly it is likely to go extinct. The model suggests that that diploid populations with fewer than 50 mature individuals will become extinct faster than those with more than 200 plants, and that long-term viability requires more than 400 reproductive plants with at least 20 self-incompatibility alleles (Young et. al 2000b; Young, unpublished data, in NSW OEH 2012).

Translocation Rutidosis leptorrhynchoides is recognised both locally and nationally as an endangered species. Increasing the number of populations through the establishment of new, self-sustaining populations is identified as a key management objective for the preservation of R. leptorrhynchoides in perpetuity in the wild (ACT Government 2017).

Methodology

Recipient sites

The recipient sites are located within the Molonglo River Reserve - Barrer Hill restoration area (Map 1). The restoration area supports potentially suitable habitat, is within the species known range and is believed to have supported R. leptorrhynchoides in the past. Furthermore, the Molonglo River Reserve is recognised as a biodiversity offset with significant and ongoing funding committed to the restoration, protection and management of reserve.

Four recipient sites have been identified within patches of natural temperate grassland and box-gum woodland secondary grassland within the Barrer Hill restoration area (Map 1). All sites are between 40 m and 320m of each other and have been selected based on specific microhabitat attributes such as soil type and depth, dominant grass type, low grass structure, gap availability/ inter-tussock spaces, level of weed infestation and aspect.

Map 1. Recipient site locations. Maps include location of known extant Rutidosis leptorrhynchoides populations in the ACT and occurrence of other threatened species at the recipient site.

Site 1 (149o2’42.642”E; 35 o18’23.865”S): The site is gently sloped on a slight westerly aspect. The site is dominated by native grasses and forbs, including Austrostipa bigeniculata, Rytidosperma sp., Leucochrysum albicans, Xerochrysum viscosum, Chrysocephalum apiculatum, Chrysocephalum semipapposum, Vittadinia muelleri and Linum marginata. Weed species present at the site include: Eragrostis curvula, Hypericum perforatum, Carthamus lanatus, Vulpia sp., Conyza sp. and Hypochaeris radicata. There are large inter- tussock spaces with extensive areas of bare ground. Vegetation structure is highly variable.

In 2015 the site was scalped to a depth of 15cm to remove bulk nutrients and weed seed bank. The site was seeded with a high diversity of native grasses and forbs.

Bare earth = 88%

Rocks = 0%

Litter = 28%

Annual introduced grass and forbs = 6%

Perennial introduced grass and forbs = 0%

Native grasses = 34%

Native forbs = 8%

Site 1. Scalped grassland restoration site

Site 2 (149o2’43.145”E; 35 o18’25.939”S): The site is moderately sloped on a southerly aspect within an erosion gully. The soil is extremely shallow and rocky. The dominant vegetation type is Bothriochloa macra and Themeda australis. Other native species include Rytidosperma sp., Chrysocephalum apiculatum, Wahlenbergia sp. and Acaena ovina. Weed species present at the site include, Hypericum perforatum, Plantago lanceolata, Chondrilla sp., Sanguisorba minor and Conyza sp. There are extensive areas of bare ground and vegetation structure is very low.

Bare earth = 70%

Rocks = 24%

Litter = 4%

Annual introduced grass and forbs = 2%

Perennial introduced grass and forbs = 2%

Native grasses = 22%

Native forbs = 0%

Site 2. Erosion gully.

Site 3 (149o2’21.191”E; 35 o18’28.731”S): The site is moderately to steeply sloped on a westerly aspect. The site is extremely rocky with very shallow soils. The site is dominated by Themeda australis. Other native grass and forb species include Poa sieberiana and Chrysocephalum apiculatum. Kunzea ericoides is present upslope of the site. Weed species include Hypericum perforatum, Eragrostis curvula and Chondrilla sp. There are large inter-tussock spaces with large areas of bare ground. Vegetation structure is moderate to low and highly variable.

The site is within pink-tailed worm-lizard Aprasia parapulchela habitat.

Bare earth = 40%

Rocks = 8%

Litter = 10%

Annual introduced grass and forbs = 0%

Perennial introduced grass and forbs =0%

Native grasses = 74%

Native forbs = 4%

Site 3. Moderate quality pink-tailed worm-lizard habitat

Site 4 (149o2’33.541”E; 35 o18’24.539”S): The site is steeply sloped on a northerly aspect. The site is extremely rocky with shallow soils. The site is dominated by Themeda australis. Other native grass and forb species include Poa sieberiana, Sorgum leiocladum, Cheilanthes austrotenuifolia and Chrysocephalum apiculatum. Weed species include Hypericum perforatum and Conyza sp. There are moderate inter-tussock spaces with some areas of bare ground. Vegetation structure is moderate to low and highly variable.

The site is within pink-tailed worm-lizard Aprasia parapulchela habitat.

Bare earth = 30%

Rocks = 14%

Litter = 16%

Annual introduced grass and forbs = 2%

Perennial introduced grass and forbs =2%

Native grasses = 60%

Native forbs = 20%

Site 4. High quality pink-tailed worm-lizard habitat.

Site history

From the 1920s the Barrer Hill restoration area and surrounding land was used for recreation, forestry operations and grazing, with no evidence of pasture improvement. In 2011 the site was recognised as an indirect biodiversity offset for the surrounding Molonglo Valley development and grazing and forestry operations at the site were restricted. The area is now undergoing extensive ecological restoration works, including weed control, tree, shrub and groundstorey plantings, scalping, direct seeding, pink-tailed worm- lizard habitat restoration, placement of woody debris and erection of vertical habitat structures. As a commitment under the Molonglo Valley NES Plan (ACTPLA 2011) – the ACT Government is required to restore the site back to Box-gum woodland over the next 30 years. The site is currently classified as Special Purpose Reserve; however the declaration of the site as a Nature Reserve is expected in late 2017. R. Leptorrhynchoides is believed to have gone locally extinct in the area due to competition with weeds, cattle grazing, urban development and forestry operations.

Number of plants to be translocated

May 2017 – 1600 plants will be planted across the four recipient sites. 500 plants will be supplied by ANBG and 1100 will be supplied by GA. Each recipient site will contain 400 plants (125 from ANBG and 275 from GA).

May 2018 – a minimum of 500 enhancement plantings are planned for 2018. Number and location of plantings will be guided by 2017 plantings results.

May 2019 - a minimum of 500 enhancement plantings are planned for 2019. Number and location of plantings will be guided by 2017 and 2018 plantings results.

Plant provenance

ANBG

Seed used for the propagation of the translocation plants was collected in 2014 from the ANBG seed orchard – Acc. No. 763001 (MFFR – Department of Defence (next to Fairbain Airport). Seed collected from Acc. No.763001 is likely to have cross-pollinated with the adjacent orchard, including Acc. No. 8102142 (NW of Capital Hill, between State and Capital Circles) and Acc. No. 8008791 (Stirling Ridge, N end). Note: no information is available on number of parent plants sampled.

GA

Seed used for the propagation of the translocation plants was collected from the GA seed orchard (Aranda, ACT). GA seed orchard plants originated from seed collected from Majura Firing Range and Stirling Ridge. Translocation plants are likely to have been cross-pollinated by these two populations. Note: no information is available on number of parent plants sampled.

Propagation method

ANBG

Seed was sown directly into 40mm pots containing our standard native potting mix (good quality mix of pine mulch, coir with a 10% sand component). A ‘pinch’ of seed was surface sown into each pot on 2nd February.

Initial growing conditions were: Air temp- 18-26°C Relative humidity- 45-50% Bottom (bench) heat- 20-25°C Watered twice daily

Plants were watered one to two times a day depending on weather and all plants received a liquid fertiliser.

GA Seed was sown directly into trays and then pricked out into pots.

Planting schedule

Plantings will be undertaken in May 2017, 2018 and 2019. The location of plantings in May 2018 and 2019 will be informed by the survival of plantings in 2017. Plantings will be staggered across multiple years to:

- reduce the adverse consequences of stochastistic events, such as drought or other unfavourable establishment conditions;

- increase the likelihood of planting during favourable establishment conditions;

- establish multi-aged stands within the translocated populations;

- reduce resources required to undertake the translocation;

- provide for an adaptive management approach where results from previous years are used to guide further translocations, thereby ensuring further resources are not inappropriately invested into the translocation.

Planting design 2017

Each recipient site will be 1 x 25 m and contain 400 plants. Plantings will occur every 20cm along four 25m lines spaced 33cm apart (Figure 2). Plantings will occur across slope for site 1 (i.e. planting lines will follow contours) and downslope for sites 2, 3 and 4 (i.e. planting lines will be positioned against contours). Lines 1 and 4 will contain a mix of plants sourced from ANBG and GA. Line 2 will contain GA only plants and line 3 will contain ANBG plants only. Lines 2 and 3 will be used to compare survival rates of plants from the two different suppliers (i.e. GA vs ANBG) as well as importance of position on slope. Results will be used to determine propagation method and planting location for 2018 and 2019 enhancement plantings.

Tree guards

Corflute tree guards will be placed on every forth plant in lines 1 and 4 (50 plants per recipient site and 200 across all recipient sites). Plant survival and growth will be compared between guarded and every second non-guarded plant in lines 1 and 4 (i.e. 50 guarded and 50 non-guarded plants per recipient site; Figure 2). Results will be used to guide the use of tree guards in 2018 and 2019 enhancement plantings.

Figure 2. Translocation planting design 2017.

Site preparation

Minimal site preparation is required. All sites were selected based on their condition, minimal occurrence of weeds and availability of key habitat requirements such as bare earth and low biomass.

Preparation for planting tubestock will include:

- Water all tubestock before planting - Dig holes at least x 2 pot size – making sure there is no glazing on the sides or bottom of planting holes - Place some loose soil in the bottom of the holes to assist with root establishment. - Fill holes with water before planting. - Trim any excess roots protruding from the bottom of the pot prior to planting. - Plant tubestock at ground level. - Compress soil around tubestock to collapse air pockets and to create a depression to capture water. - Water thoroughly

Maintenance

Plants will only be watered on the day of planting unless conditions are unseasonably dry. Watering and weed control will be undertaken on as required basis.

The management of biomass and vegetation structure is expected to be minimal. In the event that vegetation density increases and litter builds up – vegetation structure will be managed using a combination of brushcutting, physical removal and/or herbicide application to ensure suitable levels of bare earth and intertussock spaces are available. In the event that kangaroo and/or wallaroo densities increase and overgrazing at the site becomes an issue - temporary fencing will be established on an as required basis.

Monitoring and experimental design

Key monitoring questions:

Short-term questions

1. What percentage of plants survived to 6 months (December 2017) and 18 months (December 2018)?

2. Which recipient site had the best survival rate after 6 months?

3. What percentage of plants survived to reproductive stage?

4. Does position on slope influence survival rate?

5. Did GA or ANBG sourced plants have the greatest survival rate at 6 and 18 months?

6. Do tree guards significantly improve survival rate at 6 and 18 months?

Long-term questions

7. Have we created a self-sustaining population? 8. Is the population being sustained or increased through natural recruitment?

9. Are new seedlings surviving to reproductive stage?

Habitat management questions

10. Have key weed species such as African lovegrass, Chilean needlegrass and St Johns wort been eradicated within and immediately adjacent to the translocation sites?

11. Has the availability of large inter-tussock spaces and bare earth been maintained at the translocation sites?

Monitoring methods

Plant survival, flowering and recruitment will be monitored annually in December at each of the recipient sites until 2020. Following this period, plant survival and recruitment will be monitored every three years.

Question 1-5 will be addressed through monitoring plant survival and recruitment in planting lines 2 and 3 at each of the four recipient sites.

Questions 6 will be addressed through monitoring plant survival in a subset of plants (25 guarded and 25 non-guarded) from planting lines 1 and 4 at each of the four recipient sites.

Note: the planting design ensures the location of every plant is known and removes the requirement to individually and permanently tag each plant. Furthermore, this approach quickly allows us to determine whether plants are successfully recruiting.

Risk management

Key risks include:

1. Translocation fails. In the event that the translocation fails there will be minimal to no impact on the conservation of extant populations of the target species. All seed used in the translocation was sourced from established seed orchards. No seed was removed from natural populations for the purpose of this introduction.

2. Impacts on other natural values. Recipient sites 3 and 4 both support suitable habitat for the threatened pink-tailed worm-lizard. While soil will be disturbed during the planting process all works will be undertaken during winter when pink-tailed worm-lizards are inactive and most likely to be deep within their burrows under rocks. Furthermore, the condition of pink-tailed worm-lizard habitat both within and adjacent to the translocation sites are likely to be improved through dedicated weed control works and fine scale management of the sites.

Funding

TMS1408C Molonglo Valley NES Plan Stage 2 approved in 2014-15 Budget. The funds provide for a four year program of works specifically to implement the NES Plan commitments. Funding for monitoring is included in staff budgets (ACT Government 2016).

References ACT Government. 2017. Draft ACT Native Grassland Conservation Strategy and Action Plans. Environment, Planning and Sustainable Development Directorate, Canberra. Lunt, I.D. 1990. Floristic survey of the Derrimut Grassland Reserve, Melbourne, Victoria. Proc. Roy. Soc. Vic. 102(1): 41-52. McDougall, K.M. 1987. Sites of Botanical Significance in the Western Region. Department of Geography, University of Melbourne. Morgan, J.W. 1995a. Ecological studies of the endangered Rutidosis leptorrhynchoides I. Seed production, soil seed bank dynamics, population density and their effects on recruitment. Aust. J. Bot. 43(1):1-11. Morgan, J.W. 1995b. Ecological studies of the endangered Rutidosis leptorrhynchoides II. Patterns of seedling emergence and survival in a native grassland. Aust. J. Bot. 43(1):13-24. Morgan J.W. 1997. The effect of grassland gap size on establishment, growth and flowering of the endangered Rutidosis leptorrhynchoides (Asteraceae) J. Applied Ecology 34(3): 566-576. Morgan J.W. 2000. Reproductive success in re-established versus natural populations of a threatened grassland daisy (Rutidosis leptorrhynchoides) Cons. Biology 14(3): 780-785. Morgan, J.W. and Scacco, P.J. 2006. Planting designs in ecological restoration: insights from the Button Wrinklewort. Ecological Management and Restoration 7: 51-54. Murray, B.G. and Young, A.G. 2001. Widespread chromosome variation in the endangered grassland forb Rutidosis leptorrhynchoides F. Muell. (Asteraceae: Gnaphalieae). Annals of Botany 87: 83-90. NSW Office of Environment and Heritage (2012). National Recovery Plan for Button Wrinklewort Rutidosis leptorrhynchoides. NSW Office of Environment and Heritage, Hurstville. Pickup, M. and Young, A.G. 2008. Population size, self-incompatibility and genetic rescue in diploid and tetraploid races of Rutidosis leptorrhynchoides (Asteraceae). Heredity 100: 268–274. Wells, G.P. and Young, A.G. 2002. Effects of seed dispersal on spatial genetic structure in populations of Rutidosis leptorrhynchoides with different levels of correlated paternity. Genetical Research 79: 219- 226 2002. Young, A.G., Miller, C., Gregory, E.A. and Langston, A. 2000a. Sporophytic self-incompatibility in diploid and tetraploid races of Rutidosis leptorrhynchoides. Aust. J. Bot. 48: 667-672. Young, A.G., Brown, A.H.D., Murray, B.G., Thrall, P.H. and Miller, C.H. 2000b. Genetic erosion, restricted mating and reduced viability in fragmented populations of the endangered grassland herb: Rutidosis leptorrhynchoides. In: A.G. Young and G.M. Clarke (eds) Genetics, Demography and Viability of Fragmented Populations. Cambridge University Press. pp. 335-359. Young, A.G. and Pickup, M. 2010. Low S-allele numbers limit mate availability, reduce seed set and skew fitness in small populations of a self-incompatible plant. Journal of Applied Ecology 2010, 47: 541–548.