This Conservation Advice was approved by the Minister / Delegate of the Minister on: 3/07/2008. Approved Conservation Advice (s266B of the Environment Protection and Biodiversity Conservation Act 1999) Approved Conservation Advice for Prostanthera densa (Villous Mintbush)
This Conservation Advice has been developed based on the best available information at the time this conservation advice was approved.
Description Prostanthera densa, Family Lamiaceae, also known as Villous Mintbush, is an aromatic, low, erect, compact shrub 0.5–2 m tall (up to 1 m in the southern parts of its range). The leaves are in pairs and almost triangular in shape, to 15 mm long and 12 mm wide (DECC NSW, 2005a). Flowers are pale mauve to mauve with white and orange markings in the throat (Althofer, 1978; Fairley & Moore, 1989; Harden, 1992). Flowering has been observed throughout the year (Harden, 1992), but occurs chiefly in spring (Carolin & Tindale, 1993) or from May–December (Fairley & Moore, 1989). Conservation Status Villous Mintbush is listed as vulnerable. This species is eligible for listing as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) as, prior to the commencement of the EPBC Act, it was listed as vulnerable under Schedule 1 of the Endangered Species Protection Act 1992 (Cwlth). Villous Mintbush is also listed as vulnerable under Schedule 3 of the Threatened Species Conservation Act 1995 (NSW).
Distribution and Habitat Villous Mintbush is known from Nelson Bay to Beecroft Peninsula, NSW (Harden, 1992). This species has also been recorded from the Currarong area in Jervis Bay (DECC NSW, 2005a). Select localities are Cronulla, Garie Beach, Royal National Park, and Gan Gan Hill, Nelson Bay (Althofer, 1978; DECC NSW, 2005a). The Sydney and Royal National Park populations were thought possibly extinct (DECC NSW, 2005a), but the species is now known to occur at Bass and Flinders Point in Cronulla (Australian Plant Society, 2007). This species occurs within the Hunter–Central Rivers, Sydney Metro and Southern Rivers (NSW) Natural Resource Management Regions. Villous Mintbush grows in sclerophyll forest and shrubland on coastal headlands and near- coastal ranges, chiefly on sandstone (Harden, 1992), and rocky slopes near the sea (Fairley & Moore, 1989). Plants regenerate from rootstock after fire (DECC NSW, 2005a). The distribution of this species is not known to overlap with any EPBC Act-listed threatened ecological communities.
Threats The main identified threat to Villous Mintbush is urban development (Harden, 1992). The main potential threats include dieback caused by Phytophthora cinnamomi, as this has affected nearby vegetation, grazing by Rusa Deer (Cervus timorensis) in Royal National Park, and inappropriate fire regimes (DECC NSW, 2005a).
Research Priorities Research priorities that would inform future regional and local priority actions include: • Design and implement a monitoring program.
Prostanthera densa Conservation Advice - Page 1 of 4 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 3/07/2008. • More precisely assess population size, distribution, ecological requirements and the relative impacts of threatening processes. • Undertake survey work in suitable habitat and potential habitat to locate any additional populations/occurrences/remnants. • Undertake seed germination and/or vegetative propagation trials to determine the requirements for successful establishment. • Conduct susceptibility trials and monitor populations for the impact of dieback caused by Phytophthora cinnamomi (DECC NSW, 2005a).
Regional Priority Actions The following regional priority recovery and threat abatement actions can be done to support the recovery of Villous Mintbush. Habitat Loss, Disturbance and Modification • Monitor known populations to identify key threats. • Monitor the progress of recovery, including the effectiveness of management actions and the need to adapt them if necessary. • Identify populations of high conservation priority. • Ensure road widening and maintenance activities (and other infrastructure or development activities involving substrate or vegetation disturbance) in areas where Villous Mintbush occurs do not adversely impact on known populations. • Investigate formal conservation arrangements such as the use of covenants, conservation agreements or inclusion in reserve tenure. Fire • Develop and implement a suitable fire management strategy for Villous Mintbush. • Identify appropriate intensity and interval of fire to promote vegetation regeneration. • Provide maps of known occurrences to local and state rural fire services and seek inclusion of mitigative measures in bush fire risk management plans, risk register and/or operation maps. Diseases, Fungi and Parasites • Develop and implement suitable hygiene protocols to protect known sites from further outbreaks of dieback caused by Phytophthora cinnamomi. Conservation Information • Raise awareness of Villous Mintbush within the local community. Enable Recovery of Additional Sites and/or Populations • Undertake appropriate seed collection and storage. • Investigate options for linking, enhancing or establishing additional populations. • Implement national translocation protocols (Vallee et al., 2004) if establishing additional populations is considered necessary and feasible.
Local Priority Actions The following local priority recovery and threat abatement actions can be done to support the recovery of Villous Mintbush. Habitat Loss, Disturbance and Modification • Survey and map to confirm records including Royal National Park, Cronulla, Nelsons Bay, and Jervis Bay (DECC NSW, 2005b). • Conduct searches in suitable habitat in proposed development areas (DECC NSW, 2005a).
Prostanthera densa Conservation Advice - Page 2 of 4 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 3/07/2008. • Protect populations of the listed species through the development of conservation agreements and/or covenants. Trampling, Browsing or Grazing • Implement the management plan for the control and eradication of Rusa Deer in Royal National Park (DECC NSW, 2005b). Fire • Implement an appropriate fire management regime for local populations. Diseases, Fungi and Parasites • Develop and implement suitable hygiene protocols to protect known populations from further outbreaks of dieback caused by Phytophthora cinnamomi.
This list does not necessarily encompass all actions that may be of benefit to Villous Mintbush, but highlights those that are considered to be of highest priority at the time of preparing the conservation advice.
Existing Plans/Management Prescriptions that are Relevant to the Species • Threat Abatement Plan for Dieback Caused by the Root-Rot Fungus Phytophthora cinnamomii (EA, 2001), • Deer Management Plan for Royal National Park and Reserves in Sydney South Region (DECC NSW, 2005c), and • The Royal National Park, Heathcote National Park and Garawarra State Recreation Area Plan of Management (NSW NPWS, 2000). These prescriptions were current at the time of publishing; please refer to the relevant agency’s website for any updated versions.
Information Sources: Althofer, GW 1978, Cradle of Incense, SGAP, Sydney. Australian Plant Society 2007, Sutherland Group Newsletter May 2007, viewed 26 March 2008,
Prostanthera densa Conservation Advice - Page 3 of 4 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 3/07/2008. Vallee, L, Hogbin, T, Monks, L, Makinson, B, Matthes, M & Rossetto, M 2004, Guidelines for the Translocation of Threatened Plants in Australia - Second Edition, Australian Network for Plant Conservation, Canberra.
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