Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Vulnerable
Recovery Plan Decision Recovery Plan required, this species had a recovery plan in force at the time the legislation provided for the Minister to decide whether or not to have a recovery plan (19/2/2007).
 
Adopted/Made Recovery Plans Wellington Mint-bush Prostanthera galbraithiae - National Recovery Plan (Carter, O. & N. Walsh, 2006r) [Recovery Plan].
 
Federal Register of
    Legislative Instruments
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument].
 
State Government
    Documents and Websites
VIC:Flora and Fauna Guarantee Action Statement 231-Wellington Mint-bush Prosthanthera galbraithiae (Victorian Department of Sustainability and Environment (Vic. DSE), 2008ae) [State Action Plan].
State Listing Status
VIC: Listed as Threatened (Flora and Fauna Guarantee Act 1988 (Victoria): May 2014 list)
Non-statutory Listing Status
VIC: Listed as Vulnerable (Advisory List of Rare or Threatened Plants in Victoria: 2005)
Scientific name Prostanthera galbraithiae [64959]
Family Lamiaceae:Lamiales:Magnoliopsida:Magnoliophyta:Plantae
Species author Conn
Infraspecies author  
Reference Telopea 7(4): 321 (1998).
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

Scientific name: Prostanthera galbraithiae

Common name: Wellington Mintbush

Other names: Holey Plains Mintbush

Conventionally accepted as Prostanthera galbraithiae (CHAH 2010).

The Wellington Mintbush is an erect to spreading small shrub growing to 2 m high. It often grows through, and supported by, other vegetation (Walsh & Entwisle 1994, cited in Gippsland Water 2012).

Some young branches occasionally appear square shaped in cross section, with dense hairs between two faint lateral-running ridges and on nodes while the rest of the branch is hairless. Leaves are mid-green, 15 mm x 2 mm, stalkless, in opposite pairs and mostly hairless. Leaves are narrowly ovate (egg-shaped) or oblong, but often appear linear as margins are strongly folded back. They have a slight aroma when crushed.

Flowers are deep mauve to purple with darker spots on the petals and are arranged in groups of 8 to 24. Petals are 7-10 mm long; the two upper petals form a hood and the three lower petals are spread fan-shape; and the middle petal is the broadest and longest. Stamens have anthers that lack a basal (bottom) appendage (external body part). The surrounding calyx (group of modified leaves) is divided into two lips, with the upper lip curved backwards and 6 mm in length (Vic. DSE 2008ae; Walsh & Entwisle 1999).

The Wellington Mintbush is endemic to the central Gippsland region of southeast Victoria, where it is known from Holey Plains State Park, and the Dutson Downs Sewerage Treatment area (Carter & Walsh 2006r; Conn 1998).

All populations of the Wellington Mintbush are likely to be important for the long-term survival of the species (Vic. DSE 2008ae).

There are 12 known populations containing approximately 850 plants (Carter & Walsh 2006r; Vic. DSE 2008ae). Ten of the known populations occur in Holey Plains State Park, and two populations are  known from the Dutson Downs waste disposal and treatment site (Carter & Walsh 2006r; Vic. DSE 2008ae).

The Dutson Downs populations are geographically disjunct. These populations are approximately 20 km east of the nearest Holey Plains population (Carter & Walsh 2006r).

Populations occur in the following locations (Carter & Walsh 2006r; Vic. DSE 2008ae):

Location Site Number of plants
Holey Plains State Park, managed by Parks Victoria Red Hill Track, 'Berlin Wall' 540
Red Hill Track, 3 km east of Kellys Track: 100
Kellys Track 20
Berminghams Road 150
Springs Track 25
Between Kellys Track, Seldom Seen Track and South Boundary Track 1 plant recorded in
1986, none seen since
South Boundary Track 10-20 plants recorded in 1992
Holey Hill 1 plant recorded in 1986, none seen since
Chessum Rd 1 4 plants recorded in 1986, none seen since
Chessum Rd 2 1 plant recorded in 1986 and 2002
Dutson Downs, managed by Gippsland Water Private land Approximately 300 plants in two populations

The species was probably highly localised between the Holey Plains and Dutson Downs areas, but more widespread than currently known. Several populations have not been relocated for many years, suggesting decline is still ongoing. However, the fire-dependent nature of the Wellington Mintbush may indicate populations are still present as seed in the soil seed bank waiting for fire to germinate (Vic. DSE 2008ae).

As the species is fire dependant for germination, with a life span of approximately 18 years, some known populations may be absent at certain times, depending on the period since the last fire at that site (Carter & Walsh 2006r).

Populations of the Wellington Mintbush occur in heathy open forest, heathland and heathy woodland, usually on gravelly sand overlaying clay (Conn 1998; Walsh & Entwisle 1999).

Associated flora species include Spike Wattle (Acacia oxycedrus), Sweet Wattle (A. suaveolens), Silver Banksia (Banksia marginata), Sticky Boronia (Boronia anemonifolia), Thick Twist-rush (Caustis pentandra), Showy Parrot-pea (Dillwynia sericea), Burgan (Kunzea ericoides), Sandhill Sword-sedge (Lepidosperma concavum), Prickly Tea-tree (Leptospermum continentale), Heath Tea-tree (Leptospermum myrsinoides) (Carter & Walsh 2006r; Vic. DSE 2008ae), Common Heath (Epacris impressa), Messmate (Eucalyptus obliqua) and Common Flat-pea (Platylobium obtusangulum) (Conn 1998). In disturbed sites, the ground layer may be dominated by bracken fern (Pteridium esculentum) (Conn 1998).

The Wellington Mintbush has a lifespan of approximately 18 years, though plants begin declining, in reproductive capacity, after approximately ten (Carter & Walsh 2006r) to fifteen years (Vic. DSE 2008ae).

The species flowers in September and October (Walsh & Entwisle 1999), and is strongly reliant on disturbance, such as fire, for seed germination (Carter & Walsh 2006r; Vic. DSE 2008ae). Flowering of mature plants peaks around seven to ten years after a fire event (Vic. DSE 2008ae). The seed is also suggested to have a short viability, with an approximate fire interval (time between fire events) of 15 years to maintain populations (Vic. DSE 2008ae).

Wellington Mintbush is distinguished from other species of Prostanthera by the stalkless linear leaves and the lower middle petal which is broader and longer than each of the two upper petals (Conn 1998).

The Wellington Mintbush's extent of occurrence has most likely declined due to land clearance for settlement, agriculture and pine plantations.

Below are threats that have been identified for the Wellington Mintbush (Carter & Walsh 2006r; Vic. DSE 2008ae).

Inappropriate fire regimes
Based on the lifespan of the species, fire intervals of approximately 15 years are suggested. Fire intervals of less than 10 years may be detrimental to the species, as plants may not have reached maturity and set seed. Historically, frequent fire intervals of one to three years at Dutson Downs caused the extinction of a population.

Disturbance activities
Disturbance from maintenance of firebreaks and road works has ensured the survival of some isolated populations in the absence of fire. However, too frequent soil disturbance would deplete the soil seed bank, and also not allow plants to mature and set seed.

Herbicide use
Aerial herbicides are used in nearby pine plantations, and drift from chemicals may affect nearby populations.

Browsing/grazing
Wallaby species that utilise surrounding Pine plantations for habitat browse on the Wellington Mintbush, with greater damage done in smaller populations of less than 20 plants. Prolonged drought conditions may also contribute to increased grazing pressure.

Competition
The Holey Hill population is threatened by competitive exclusion from Bracken Fern (Pteridium esculentum).

The National Recovery Plan for the Wellington Mintbush Prostanthera galbraithiae (Carter & Walsh 2006r) outlines the following objectives to assist in recovery of the species:

  • Acquire accurate information for conservation status assessments.
  • Identify habitat that is critical, common or potential.
  • Ensure that all populations and their habitat are protected and managed appropriately.
  • Manage threats to populations.
  • Identify key biological functions.
  • Determine the growth rates and viability of populations.
  • Establish populations in cultivation.
  • Establish cultivated plants in the wild.
  • Build community support for conservation.

Previous management actions, which aid the protection of the species, have been undertaken, including (Vic. DSE 2008ae):

  • Field inspections and population counts, and the entering of sites on the Flora Information System database
  • Liaison between Parks Victoria and Gippsland Water about locating populations and identifying the species at Dutson Downs
  • The mapping of approximately two-thirds of the species' distribution in the Holey Plains State Park
  • Documentation of the species' response to past fuel reduction and wildfires, and discussion of its fire response with the Royal Botanic Gardens
  • Documentation of two big populations in areas of past soil disturbance
  • The recording of the species' life cycle which has lead to new life history information relevant to recovery actions

Management documents relevant to the Wellington Mintbush are at the start of the profile.

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Biological Resource Use:Logging and Wood Harvesting:Habitat disturbance due to foresty activities Species threats data recorded on the SPRAT database between 1999-2002 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012i) [Database].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Wellington Mint-bush Prostanthera galbraithiae - National Recovery Plan (Carter, O. & N. Walsh, 2006r) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Slashing and herbicide application for weed control Wellington Mint-bush Prostanthera galbraithiae - National Recovery Plan (Carter, O. & N. Walsh, 2006r) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, predation and/or habitat degradation by kangaroos and wallabies Wellington Mint-bush Prostanthera galbraithiae - National Recovery Plan (Carter, O. & N. Walsh, 2006r) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Wellington Mint-bush Prostanthera galbraithiae - National Recovery Plan (Carter, O. & N. Walsh, 2006r) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate prescribed regimes and/or vegetation management to control fire regimes Species threats data recorded on the SPRAT database between 1999-2002 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012i) [Database].
Natural System Modifications:Natural System Modifications:Indirect and direct habitat loss due to human activities Prostanthera galbraithiae in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006sn) [Internet].
Species Stresses:Indirect Species Effects:Low numbers of individuals Prostanthera galbraithiae in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006sn) [Internet].

Carter, O. & N. Walsh (2006r). Wellington Mint-bush Prostanthera galbraithiae - National Recovery Plan. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/p-galbraithiae.html.

Conn, B.J. (1998). Contributions to the systematics of Prostanthera (Labiatae) in south-eastern Australia. Telopea. 7(4):319-332.

Council of Heads of Australasian Herbaria (CHAH) (2010). Australian Plant Census. [Online]. Australian National Herbarium, Australian National Botanic Gardens and Australian Biological Resources Study . Available from: http://www.anbg.gov.au/chah/apc/.

Gippsland Water (2012). Environmental Management - Wellington Mintbush. [Online]. Available from: http://www.gippswater.com.au/AboutUs/EnvironmentalManagement.aspx.

Royal Botanic Gardens Melbourne (RBGM) (2012). Prostanthera galbraithiae at the Royal Botanic Gardens Melbourne. [Online]. Available from: http://www.rbg.vic.gov.au/dbpages/rbgcensus/index.php/census/species_detail/28888.

Victorian Department of Sustainability and Environment (Vic. DSE) (2008ae). Flora and Fauna Guarantee Action Statement 231-Wellington Mint-bush Prosthanthera galbraithiae. [Online]. Available from: http://www.dse.vic.gov.au/plants-and-animals/flora-and-fauna-guarantee-act-action-statements-index-of-approved-action-statements.

Walsh, N.G. & T.J. Entwisle. (eds) (1999). Flora of Victoria, Volume Four. Melbourne, Royal Botanic Gardens, Inkata.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Prostanthera galbraithiae in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Tue, 30 Sep 2014 22:23:48 +1000.