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 Critically Endangered as Caladenia actensis
Listing and Conservation Advices Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
 
Recovery Plan Decision Recovery Plan required, included on the Commenced List (1/11/2009).
 
Adopted/Made Recovery Plans National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan] as Caladenia actensis.
 
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 (13/05/2005) (Commonwealth of Australia, 2005g) [Legislative Instrument] as Arachnorchis actensis.
 
Amendment to the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (95) (16/12/2009) (Commonwealth of Australia, 2009a) [Legislative Instrument] as Caladenia actensis.
 
State Government
    Documents and Websites
ACT:Canberra Spider Orchid (Arachnorchis actensis). An endnagered species (Australian Capital Territory Department of Territory and Municipal Services (ACT TAMS), 2006h) [Information Sheet].
ACT:Action Plan for the Canberra Spider Orchid (Arachnorchis actensis) (Frawley, K., 2010b) [State Action Plan].
State Listing Status
ACT: Listed as Endangered (Nature Conservation Act 1980 (Australian Capital Territory): 2013 list) as Arachnorchis actensis
Scientific name Caladenia actensis [76138]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author D.L.Jones & M.A.Clem.
Infraspecies author  
Reference The Orchadian 12(11): 522 (1999).
Other names Arachnorchis actensis [76137]
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 actensis

Common name: Canberra Spider-orchid

Previous name: Caladenia actensis

Arachnorchis actensis is conventionally accepted as a species. It was originally described as Caladenia actensis (Jones & Clements 1999). However, a revision in 2002 of the genus Caladenia resulted in this species being renamed Arachnorchis actensis (Jones et al. 2001).

The Canberra Spider-orchid is a terrestrial orchid growing to between 4 and 9 centimetres. The greenish flowers are heavily marked with reddish crimson lines (Jones & Clements 1999).

The Canberra Spider-orchid is endemic to the Australian Capital Territory. It is currently only known from two populations on the western lower slopes of Mount Ainslie and Mount Majura, in the Canberra Nature Park (Jones & Clements 1999). It was previously recorded from sites at Aranda and Campbell (CANB herbarium records), but it no longer exists at either of these locations. Extensive surveys of suitable locations have failed to locate the species outside its previously known range (Jones & Clements 1999; P.Milburn 2006, pers. comm.; D.Rouse 2006, pers. comm.).

The Canberra Spider-orchid has an extent of occurrence of approximately five hectares (0.05 km2) (D.L.Jones 2005, pers. comm.).

In a survey in spring 2003, the Canberra Spider-orchid was found at ten sites in two locations. Extensive surveys were also carried out in other suitable locations in spring 2003, but failed to locate any plants outside the previously known range (P.Milburn 2006, pers. comm.).

Extensive searches were carried out in previous years in the Campbell area where the species has previously been recorded, but no plants were located (D.Rouse 2006, pers. comm.).

The entire Canberra Spider-orchid population consists of approximately 250 plants, at two locations in the Canberra Nature Park (Jones & Clements 1999).

The Canberra Spider-orchid exists in two populations. These populations are located on the lower western slopes of Mount Ainslie (approximately 30 plants) and Mount Majura (approximately 220 plants) (Jones & Clements 1999).

In the last 40 years the Canberra Spider-orchid has been reduced from four populations to two. The two extinct populations were located at sites that have now been developed as part of the suburbs of Aranda, on the western slopes of Black Mountain, and Campbell, on the slopes of Mount Ainslie. However, as the number of plants lost at these locations is not known, it cannot be determined by how much the total population has declined. The existing populations are subject to ongoing threats, such as urbanization, that are likely to continue the decline of these populations (Jones & Clements 1999; P.Milburn 2006, pers. comm.; D.Rouse 2006, pers. comm.).

The Canberra Spider-orchid grows on shallow gravelly brown clay loam soils of volcanic origin. Plants occur amongst a ground cover of grasses, forbs and low shrubs, often among rocks (Canberra Geology Map SI 55-16; Jones & Clements 1999).

The Canberra Spider-orchid grows in transitional vegetation zones between open grassy woodland (dominated by Eucalyptus blakelyi, E. melliodora, and E. pauciflora) and dry sclerophyll forest (dominated by E. rossii) (Jones & Clements 1999; P.Milburn 2006, pers. comm.; D.Rouse 2006, pers. comm.).

This species is a seasonal perennial. Its leaf appears from a dormant underground tuber in late autumn or early winter following good rains. Flower buds appear in late winter or early spring and plants flower from late September to mid October. Plants are insect-pollinated, probably by a thynnid wasp species. Plants die down after flowering and remain dormant over summer. Seeds require interaction with a mycorrhizal fungal host for germination (Peakall & Beattie 1996; P.Milburn 2006, pers. comm.; D.Rouse 2006, pers. comm.).

Arachnorchis actensis is easily distinguished from other spider-orchid species (Arachnorchis spp.) in the ACT by its small size and highly reduced marginal labellum teeth. It is most closely related to A. concinna (a species of the central western slopes and south-western plains of inland New South Wales) but differs in having far more reddish colouring on the flower parts (A. concinna is generally green), and occupies very different habitat (A. concinna occurs in Callitris woodland and ironbark forest ) (Jones & Clements 1999).

This species is under continued pressure from activities related to its proximity to urban areas and possible inappropriate land management. Current threats that affect the Canberra Spider-orchid are (P.Milburn 2006, pers. comm.; D.Rouse 2006, pers. comm.):

  • inappropriately timed fuel reduction burns
  • heavy vehicle damage as a result of firebreak slashing
  • trampling and bicycle damage
  • encroachment of weeds
  • new road building
  • grazing by kangaroos
  • possible illegal collection

The priority recovery and threat abatement actions required for the Canberra Spider-orchid are:

  • protection of the two sites where it is known to occur from direct physical disturbance and illegal collection;
  • incorporation of conservation measures, including management of fuel reduction burns or slashing, and weed control, into relevant Management Plans;
  • the undertaking of regular monitoring and further research to collate data on recruitment and better understand threats.

In the long term, the establishment of either an ex situ and/or additional population in the wild should be considered (TSSC 2005).

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 Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
Human Intrusions and Disturbance:Recreational Activities:Habitat degradation associated with recreational activities such as horse riding National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Human Intrusions and Disturbance:Recreational Activities:Soil disturbance and/or trampling due to bushwalking National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
Human Intrusions and Disturbance:Recreational Activities:bicycles (off road) National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Oryctolagus cuniculus (Rabbit, European Rabbit) National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Presence of pathogens and resulting disease National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, predation and/or habitat degradation by kangaroos and wallabies National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
Natural System Modifications:Other Ecosystem Modifications:Increased shading National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Pollution:Agricultural Effluents:Herbicide application National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Species Stresses:Indirect Species Effects:Low numbers of individuals National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].
Transportation and Service Corridors:Roads and Railroads:Development and/or maintenance of roads Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis) (Threatened Species Scientific Committee, 2005m) [Listing Advice].
Transportation and Service Corridors:Utility and Service Lines:Powerline easement maintenance and construction; mortality due to collision with powerlines National Recovery Plan for the Canberra Spider Orchid Arachnorchis actensis (Frawley, K., 2010) [Recovery Plan].

Threatened Species Scientific Committee (2005m). Commonwealth Listing Advice on Canberra Spider-orchid (Arachnorchis actensis). [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/species/canberra-spider-orchid.html.

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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 actensis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Wed, 30 Jul 2014 10:57:34 +1000.