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 Caladenia audasii
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 Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan] as Caladenia audasii.
 
Policy Statements and Guidelines Draft survey guidelines for Australia's threatened orchids (Department of the Environment, 2013b) [Admin Guideline].
 
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] as Caladenia audasii.
 
State Government
    Documents and Websites
VIC:Flora and Fauna Guarantee Action Statement 103 - Twelve threatened Spider-orchids Caladenia species (Todd, J., 2004) [State Recovery Plan].
State Listing Status
SA: Listed as Endangered (National Parks and Wildlife Act 1972 (South Australia): June 2011 list) as Caladenia audasii
VIC: Listed as Threatened (Flora and Fauna Guarantee Act 1988 (Victoria): February 2014 list) as Caladenia audasii
Non-statutory Listing Status
VIC: Listed as Endangered (Advisory List of Rare or Threatened Plants in Victoria: 2005)
Scientific name Caladenia audasii [11727]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author R.S.Rogers
Infraspecies author  
Reference Rogers, R.S. (1927) Contributions to the Orchidology of Australia.Transactions and Proceedings of the Royal Society of South Australia 51: 295
Other names Arachnorchis audasii [76193]
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: Arachnorchis audasii

Common name: McIvor Spider-orchid

In 2001, the genus Caladenia was reviewed (Jones et al. 2001). Caladenia audasii is now known as Arachnorchis audasii. The taxonomic status of this species has been questioned, with speculation that it may be a hybrid or an aberrant form of a sympatric species, based on its extreme rarity, apparent sporadic occurrence and variability in appearance. However, likely parent species are not readily obvious, and the composition of Caladenia species growing with the McIvor Spider-orchid varies between the three currently known sites. Also, no other species in the Caladenia patersonii complex (to which C. audasii belongs) grows at all three sites (or even nearby) where C. audasii occurs (Berwick et al. 1998a).

The McIvor Spider-orchid is a terrestrial, deciduous herb with a single leaf of 60 to 100 mm long by 8 to 10 mm wide, lanceolate in shape, green and sparsely hairy.  The species has a slender hairy, green or reddish flower stem, growing to 20 cm tall. Its labellum is pale yellow, with reddish spotting (Backhouse & Jeanes 1995).

The McIvor Spider-orchid is endemic to Victoria where it has a disjunct distribution across 200 km of the Midlands Region (Conn 1993), from Bendigo to Deep Lead. It is currently known from fewer than 20 plants in three widely scattered populations; in state forest near Deep Lead (five plants in 1989, three plants in 1991), in state forest near Inglewood (five plants in 1985, one plant in 1995) and in a flora reserve near Bendigo (four plants in 1992, three plants in 1997). It is not known if these figures represent an overall decline in the plant numbers or just seasonal fluctuations (Berwick et al 1998a). The Deep Lead Flora and Fauna Reserve contains two populations several hundred metres apart (Carr 2000 pers. comm.).

There are two old collections at the National Herbarium of Victoria: 2 December 1905 from 'Redlands', Ararat (MEL 610762); and 1896 from Bendigo, 'Mt McIvor' (type collection MEL 610760). The precise location of these two sites is currently unknown (Berwick et al. 1998a).

The species is considered extinct in South Australia (Todd 2000).

The McIvor Spider-orchid is currently known from a variety of woodland and open forest habitats. At one site it grows in a flat to gently sloping area on shallow heavy stony clay soil under Eucalyptus leucoxylon subsp. leucoxylon with a sparse shrub layer of Acacia pycnantha and a very sparse ground layer of herbs and native grasses. At another site it grows on a flat area on sandy loam in what was probably Box-Ironbark Forest, but the overstorey has since been removed and the shrub layer is frequently slashed. The third site is a gully with an overstorey of Eucalyptus nortonii, no shrub layer and a rich ground layer of herbs such as Cheilanthes spp., Pelargonium spp., Brunonia australis and native grasses. The soil at this site is a deeper, more friable sandy loam (Berwick et al. 1998a).

Flowering occurs from mid-September to mid-October, and reproduction is entirely from seed (dispersed four to eight weeks after flowering). The McIvor Spider-orchid is unable to reproduce vegetatively. Plants produce a single replacement tuber each year, and may be capable of maintaining themselves in this way for many years (Berwick et al. 1998a).

The McIvor Spider-orchid is most likely pollinated by male thynnid wasps through the process known as pseudo-copulation. There has been no natural pollination observed, with plants and/or pollinators probably being present in insufficient numbers to ensure adequate natural pollination rates. Artificial cross-pollination has been used as an ongoing management tool (Berwick et al. 1998a).

The threats facing the McIvor Spider-orchid are not clearly understood. Box-Ironbark ecosystems formerly covered about one million hectares in Victoria, but have been extensively reduced or changed since European settlement. Much has been cleared for agriculture and urban development, with the remainder extensively modified through mineral prospecting and mining, timber harvesting, grazing by stock and introduced herbivores and weed invasions. It is reasonable to assume that the distribution of this species has historically been reduced by these activities (Berwick et al 1998a).

Current threats are believed to include mineral prospecting, deliberate illicit collection, inappropriate fire regimes and grazing by native animals and rabbits. Soil disturbance and vegetation trampling from casual recreational users are problems that may lead to reduced recruitment. One site is subject to annual slashing (Berwick et al 1998a).

The Kingower population is invaded by annual grasses and freesias, and the Deep Lead population by garden escapees from rubbish dumping (Todd 2000).

The National Recovery Plan for twelve threatened spider orchids (Todd 2000) and the Victorian Department of Sustainability and Environment (Todd 2004) note the following actions that have been undertaken to assist the McIvor Spider-orchid:

- grazing management through fencing and/or caging of populations
- population monitoring
- ex-situ conservation/cultivation - seed collection and storage, mycorrhizal fungus collection and storage.

Key objectives of the recovery plan include (Todd 2000):

- Protect identified threatened Caladenia habitat.
- Protect populations from high-risk threatening processes.
- Develop and initiate fine-scale site management practices.
- Measure population trends and responses against recovery actions.
- Investigate the biology and ecology of threatened Caladenia taxa.
- Establish ex-situ collection of threatened Caladenia taxa with rapidly declining or critically low populations in the wild.
- Establish new populations of endangered Caladenia taxa in the wild.
- Develop a public education/community extension program.

 

Documents relevant to the management of the McIvor Spider-orchid can be found 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:Gathering Terrestrial Plants:Illegal collection Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Biological Resource Use:Logging and Wood Harvesting:Habitat disturbance due to foresty activities Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Energy Production and Mining:Mining and Quarrying:Habitat destruction, disturbance and/or modification due to mining activities Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Human Intrusions and Disturbance:Human Intrusions and Disturbance:Human induced disturbance due to unspecified activities Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Human Intrusions and Disturbance:Recreational Activities:Disturbance, especially from human recreational activities and development Draft Recovery Plan for Audas' Spider-orchid, Caladenia audasii, 1998-2002 (Berwick, S., A. Moorrees & G. Backhouse, 1999) [State Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Oryctolagus cuniculus (Rabbit, European Rabbit) Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Draft Recovery Plan for Audas' Spider-orchid, Caladenia audasii, 1998-2002 (Berwick, S., A. Moorrees & G. Backhouse, 1999) [State Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, predation and/or habitat degradation by kangaroos and wallabies Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate prescribed regimes and/or vegetation management to control fire regimes Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Residential and Commercial Development:Housing and Urban Areas:Habitat loss, modification and fragmentation due to urban development Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Species Stresses:Indirect Species Effects:Low numbers of individuals Recovery Plan for Audas' Spider-orchid, Caladenia audasii (Berwick, S., A. Moorrees & G. Backhouse, 1998a) [Recovery Plan].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].

Backhouse, G.N. & J.A. Jeanes (1995). The Orchids of Victoria. Carlton: Miegunyah Press, Melbourne University Press.

Berwick, S., A. Moorrees & G. Backhouse (1998a). Recovery Plan for Audas' Spider-orchid, Caladenia audasii. Melbourne: Victorian Department of NRE.

Carr, G.W. (2000). Personal Communication. Melbourne: Vic NRE.

Conn, B.J. (1993). Natural Regions and Vegetation of Victoria. In: Foreman, D.B. and N.G. Walsh, eds. Flora of Victoria: Volume One. Page(s) 79-153. Melbourne: Inkata Press.

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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). Caladenia audasii in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 10 Jul 2014 16:32:29 +1000.