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 Endangered as Rhizanthella slateri
Listing and Conservation Advices Commonwealth Listing Advice on Rhizanthella slateri (Threatened Species Scientific Committee, 2007q) [Listing Advice].
 
Approved Conservation Advice for Rhizanthella slateri (eastern underground orchid) (Threatened Species Scientific Committee (TSSC), 2014ae) [Conservation Advice].
 
Recovery Plan Decision Recovery Plan not required, the primary action identified to recover this species would be to develop alternative detection methods, which could also assist the assessment of referred actions. As this has been identified in the conservation advice, funding to develop detection methods for the species can commence. New information on distribution would need to be suitably protected (05/05/2008).
 
Adopted/Made Recovery Plans
Policy Statements and Guidelines Draft survey guidelines for Australia's threatened orchids (Department of the Environment, 2013b) [Admin Guideline].
 
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (56) (07/12/2007) (Commonwealth of Australia, 2007b) [Legislative Instrument] as Rhizanthella slateri.
 
State Government
    Documents and Websites
NSW:Rhizanthella slateri - endangered population listing (Department of Environment and Climate Change (DECC), 2008) [Internet].
NSW:Eastern Australian Underground Orchid - Profile (New South Wales Department of Environment and Climate Change (DECC), 2005d) [Internet].
NSW:Rhizanthella slateri population in the Great Lakes LGA - profile (New South Wales Department of Environment and Climate Change (NSW DECC), 2005c) [Internet].
NSW:Rhizanthella slateri - Vulnerable Species Listing (NSW Scientific Committee, 2002j) [Internet].
State Listing Status
NSW: Listed as Vulnerable (Threatened Species Conservation Act 1995 (New South Wales): August 2014 list) as Rhizanthella slateri
Scientific name Rhizanthella slateri [11768]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author (Rupp) M.Clements & Cribb
Infraspecies author  
Reference The Orchadian 8 (30 Jun. 1985) 88.
Other names Cryptanthemis slateri [22579]
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

The Eastern Underground Orchid is described as a 'terrestrial saprophytic' (grows on and derives its nourishment from dead or decaying organic matter) herb with a fleshy underground stem of 15 cm long and 15 mm diameter. The stem is whitish, often branching, with prominent, fleshy, overlapping bracts (DECC 2008; 2005c; d). Flowering heads mature below the soil surface and may extend up to 2 cm above the ground. Each flower head consists of about 25 to 35 tubular, purplish flowers arranged in a flat spiral or capitulum and has been described as looking something like a glistening purple dandelion. The flower head, which is up to 20mm across, is surrounded by fleshy bracts and is supported by a thick vertical, whitish fleshy stem also covered in bracts. The stems grow from a horizontal rhizome which has no roots, only hairs (ANOS 1997; DECC 2008; 2005d; Harden 1993).

The Eastern Underground Orchid is restricted to NSW. It is currently known only from 10 locations, including near Bulahdelah, the Watagan Mountains, the Blue Mountains, Wiseman's Ferry area, Agnes Banks and near Nowra. The population in the Great Lakes area occurs at the known northern limit of the species' range and is disjunct from other known populations of the species. The Eastern Underground Orchid is difficult to detect. It is usually located when the soil is disturbed, and there may well be more locations of the species within its known range (ANOS 1997; DECC 2005c; d; NSW SC 2005).

A further population from the Lamington Plateau in Queensland, previously regarded as Rhizanthella slateri, is now recognised as a new, as yet unnamed, species of Rhizanthella (DECC 2008).

Based on currently available information, the Eastern Underground Orchid has a relatively large extent of occurrence, from the NSW south coast to the mid north coast. However, the species is likely to have a very restricted area of occupancy, as it is known from fewer than 10 small, isolated populations within its extent of occurrence. There are insufficient data available to adequately quantify the species' geographic distribution (TSSC 2007q).

Since the species' discovery, approximately 90 individuals have been recorded (TSSC 2007q). Each recorded population has consisted of 'one' or 'a few' individuals, except the population at Bulahdelah which consists of approximately 60 individuals (TSSC 2007r). Due to the cryptic nature of the species, it is possible that more individuals occur within the known range of the species. However, based on available data, the current population estimate for the species is very low (TSSC 2007q).

Since 2005, more orchids have been found at the Bulahdelah site. The largest known population of the Eastern Underground Orchid occurs on the western slopes and base of Bulahdelah Mountain (known locally as Alum Mountain) immediately adjacent to the town of Bulahdelah, NSW. The site is the location of the first discovery of the species, and the Bulahdelah Mountain population is the type population of the species (DECC 2008).

The Eastern Underground Orchid was discovered in November 1931 at Bulahdelah Mountain (Rupp 1932), and just a few plants were found at the time, all from the one site. In 1932, another nine plants were found at the same site (Rupp 1933).

Rupp first studied the orchid in situ in 1933, again at the same site, and another six plants were found. These finds were all within a single site with "a radius of about eight yards" (Rupp 1934).

Following initial discovery, apparently the species was not seen again at Bulahdelah Mountain until 52 years later, when Clements and Groves found three plants in November 1985 in an area thought likely to be the initial site of discovery (Clements & Groves 1987).

Thereafter the species was apparently again undetected on the site for another 17 years until 2002, when local residents of Bulahdelah found two sub-populations (Carroll 2002), comprising approximately 10 flowerheads in total (NSW Roads and Traffic Authority 2005).

Due to the cryptic growth form of the species, it is likely that some populations have been destroyed before they were discovered, and that currently unknown populations may be destroyed in the future before they are discovered. The known population near Bulahdelah is therefore of critical importance to the species' conservation (DECC 2008).

The species grows in eucalypt forest but no informative assessment of the likely preferred habitat for the species is available (DECC 2005b; c).

Ancillary benefits of protecting known populations of the Eastern Underground Orchid include protection of the largest known population of Cryptostylis hunteriana (another saprophytic orchid), a threatened species under State and Commonwealth legislation, known to occur in the same area as the Eastern Underground Orchid on Bulahdelah Mountain (NSW Roads and Traffic Authority 2005), and protection of one of only three known populations of Corybas dowlingii, a relatively new and little known species of terrestrial orchid that was only described in September 2004 (Jones 2004b), also known to occur in the same area as the Eastern Underground Orchid on Bulahdelah Mountain (NSW Roads and Traffic Authority 2005).

The Eastern Underground Orchid flowers during October and November (Harden 1993).

The species occurs in the Eucalyptus forests of the Great Dividing Range, which have been cleared extensively since European settlement, and therefore the species is likely to have undergone a reduction in numbers in the past. However, there are insufficient data available to quantify this reduction (TSSC 2007q).

The largest known population of the Eastern Underground Orchid occurs on Bulahdelah (Alum) Mountain. The area where the species is known to occur overlaps with the preferred new route for the Pacific Highway. The Pacific Highway is being progressively upgraded over 10 years (TSSC 2007q). The proposal will result in the direct removal of 4% of the known population and other individuals as yet undetected may become exposed after clearing or excavation works. A further 34% of the known population is indirectly threatened by altered drainage and changes in soil moisture, and by weed invasion associated with the road. The proposed road will remove 9% of known habitat and 29% of potential habitat for the species, fragmenting the population and potentially disrupting pollination and seed dispersal (DECC 2005c).

The Eastern Underground Orchid is threatened by clearing for housing or other developments at other known sites. The species is also threatened by weed invasion, including species of exotic perennial grass. Individuals of the species are also at risk from visitation and interference by orchid enthusiasts, as once uncovered, individuals must be recovered in a specific fashion to ensure that flowerheads are not damaged by the sun. The species may be at risk of a loss of pollinator and seed dispersal vectors, such as small mammals or birds, and could be vulnerable to changes in fire regimes (TSSC 2007q; r). The extremely small population size increases the likelihood of local extinction due the environmental and demographic uncertainty (DECC 2005d).

Recovery strategies outline by the NSW Department of Environment and Climate Change (DECC 2005b; c; d) are as follows:

  • Protect areas of known habitat from clearing.
  • Investigate alternative road placement to avoid damage to this endangered population.
  • Raise awareness amongst orchid collectors about the potential damage caused by removing individual plants. This could be achieved through the erection of an information sign at the population site.
  • Investigate the potential construction of fencing to restrict access.

The Conservation Advice for the Eastern Underground (TSSC 2007r) outlines the following priority recovery and threat abatement actions required for this species:

  • Protect known sites by keeping their exact location concealed.
  • Investigate the species' numbers, biology, ecological associations, and methods of propagation and reproduction, particularly pollination biology.
  • Investigate more closely the threats to the species' survival and appropriate management actions.

The Commonwealth Conservation Advice on Rhizanthella slateri (TSSC 2007r) provides priority recovery and threat abatement actions required for the protection of the Eastern Underground Orchid.

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
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Commonwealth Listing Advice on Rhizanthella slateri (Threatened Species Scientific Committee, 2007q) [Listing Advice].
Human Intrusions and Disturbance:Human Intrusions and Disturbance:Human induced disturbance due to unspecified activities Commonwealth Listing Advice on Rhizanthella slateri (Threatened Species Scientific Committee, 2007q) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Commonwealth Listing Advice on Rhizanthella slateri (Threatened Species Scientific Committee, 2007q) [Listing Advice].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Commonwealth Listing Advice on Rhizanthella slateri (Threatened Species Scientific Committee, 2007q) [Listing Advice].
Residential and Commercial Development:Residential and Commercial Development:Habitat modification (clearance and degradation) due to urban development Commonwealth Listing Advice on Rhizanthella slateri (Threatened Species Scientific Committee, 2007q) [Listing Advice].
Species Stresses:Indirect Species Effects:Low numbers of individuals Commonwealth Listing Advice on Rhizanthella slateri (Threatened Species Scientific Committee, 2007q) [Listing Advice].

Carroll, A. (2002). Documentation of findings of Rhizanthella slateri (also known as the 'Eastern Underground Orchid') on the Alum Mountain Bulahdelah. [Online]. Available from: http://www.geocities.com/adelecarrall/rhizanthellaslateri.html. [Accessed: 29-Jan-2005].

Clements, M. & J. Groves (1987). Rare and endangered Eastern Australian Underground Orchid. Australian Natural History. 22 no. 4:182-183.

Department of Environment and Climate Change (DECC) (2005b). Eastern Australian Underground Orchid - Priority Actions. [Online]. Available from: http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/pas_profile.aspx?id=10730. [Accessed: 06-May-2008].

Department of Environment and Climate Change (DECC) (2008). Rhizanthella slateri - endangered population listing. [Online]. Available from: http://www.environment.nsw.gov.au/determinations/RhizanthellaSlateriEndSpListing.htm. [Accessed: 06-May-2008].

Harden, G.J. (ed) (1993). Flora of New South Wales, Volume Four. Kensington, NSW: University of NSW Press.

Jones, D.L. (2004b). Corybas dowlingii (Orchidaceae), a new species from north-eastern New South Wales. The Orchadian. 14 no. 9:419-420.

New South Wales Department of Environment and Climate Change (DECC) (2005d). Eastern Australian Underground Orchid - Profile. [Online]. Available from: http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/profile.aspx?id=10730. [Accessed: 06-May-2008].

New South Wales Department of Environment and Climate Change (NSW DECC) (2005c). Rhizanthella slateri population in the Great Lakes LGA - profile. [Online]. Available from: http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/profile.aspx?id=20080. [Accessed: 06-May-2008].

NSW Roads and Traffic Authority (2005). Bulahdelah Upgrade. [Online]. Available from: http://www.pb.com.au/bulahdelah/. [Accessed: 29-Jan-2005].

Rupp, Rev.H.M. .R. (1932). Notes on New South Wales orchids. In: Proceedings of the innean Society of New South Wales. LVII:57-61.

Rupp, Rev.H.M. .R. (1933). Notes on New South Wales and Queensland orchids. In: Proceedings of the innean Society of New South Wales. LVIII:225-228.

Rupp, Rev.H.M. .R. (1934). The habitat, character, and floral structure of Cryptanthemis slateri - Rupp (Orchidaceae). In: Proceedings of the innean Society of New South Wales. LIX:118-122.

The Australasian Native Orchid Society Warringah Group Inc. (ANOS) (1997). Discovery of Rhizanthella slateri (The Eastern Underground Orchid). [Online]. Available from: http://www.anos.org.au/groups/warringah/warringahframe.html. [Accessed: 06-May-2008].

Threatened Species Scientific Committee (2007q). Commonwealth Listing Advice on Rhizanthella slateri. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/352963-listing-advice.pdf.

Threatened Species Scientific Committee (2007r). APPROVED Conservation Advice on Rhizanthella slateri. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/352963-conservation-advice.pdf.

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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). Rhizanthella slateri in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Wed, 1 Oct 2014 07:00:44 +1000.