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 saggicola
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 Flora Recovery Plan: Tasmanian Threatened Orchids 2006-2010 (Threatened Species Section (TSS), 2006a) [Recovery Plan] as Caladenia saggicola.
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 saggicola.
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (05/10/2001) (Commonwealth of Australia, 2001c) [Legislative Instrument] as Caladenia saggicola.
State Government
    Documents and Websites
TAS:Caladenia saggicola (Sagg Spider-orchid): Species Management Profile for Tasmania's Threatened Species Link (Threatened Species Section (TSS), 2014x) [State Action Plan].
TAS:Flowering Times of Tasmanian Orchids: A Practical Guide for Field Botanists (Wapstra, M., N. Roberts, H. Wapstra & A. Wapstra, 2008) [Information Sheet].
State Listing Status
TAS: Listed as Endangered (Threatened Species Protection Act 1995 (Tasmania): September 2012 list) as Caladenia saggicola
Scientific name Caladenia saggicola [64859]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author D.L. Jones
Infraspecies author  
Reference Austral. Orchid Res. 3: 39 (1998).
Other names Arachnorchis saggicola [76230]
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 saggicola

Common name: Sagg Spider-orchid

In 2001, the genus Caladenia was reviewed (Jones et al. 2001). Caladenia saggicola is now known as Arachnorchis saggicola (CHAH 2005).

The Sagg Spider-orchid is a deciduous terrestrial herb (Jones 1998d) with a single leaf that is densely hairy and blotched purple at the base. Plants are 15–35 cm tall when the flower stem appears. This stem is also hairy and bears only 1 to 2 white to cream flowers with pale reddish lines and tail like extensions that have dark grey-blackish tips. Flowers are up to 70 mm across (TSS 2009).

The dorsal sepal is 30–60 mm long and 2–3 mm wide, with the lateral (lowermost) sepals 30–60 mm long and 3.5–5 mm wide and the petals are 27–50 mm long and 2–3.5 mm wide. The flowers have a labellum (lip) which is hinged at the base and bears rows of conspicuous, variously shaped and coloured calli on the upper surface. The labellum margins often also bear calli or may be deeply lobed or toothed. The labellum is white to cream, with dark reddish purple calli. The column behind the labellum is translucent with reddish markings (TSS 2009).

This species is endemic to Tasmania where it is apparently confined to the south-east (Jones 1998d). It is found on private property near Cambridge, close to the Hobart Airport, and at a local government reserve at Dodges Ferry approximately 7 kms away (TSS 2009).

The area of occupancy is less than 5 ha (TSS 2009).

A total of 202 individuals were identified at two populations in the period 2006–2008 (Larcombe 2008). Population data for the species is listed in the table below (TSS 2009):

Subpopulation Land Tenure Year last seen Area of occupancy (ha) Number of mature plants
Cambridge Private property South Carlton 2008 4-5 Up to 200
(50 plants in
Dodges Ferry Council reserve South Carlton 2007 0.001 3

This species grows in sparse woodland dominated by large old trees of Eucalyptus viminalis with a dense groundcover of tussocks of Lomandra longifolia and scattered low shrubs. The Sagg Spider-orchid grows in and between the Lomandra tussocks, on grey soil or tertiary sandy loam, at altitudes around 20 m above sea level (Jones 1998d; Jones et al. 1999).

Flowering of the Sagg Spider-orchid occurs in September and October (Jones 1998d). Reproduction is solely from seed and flowers are insect pollinated (D.L. Jones, 2001, pers. comm.).

Clearing of suitable habitat has had the most detrimental effect on the species. The two subpopulations are divided by an area of pine-plantation that would have prior to clearing provided a continuous habitat. Little suitable habitat remains in the vicinity of the two known subpopulations. Loss of habitat in the Cambridge area as a result of residential and/or commercial development remains a threat to any potential subpopulations, and as the subpopulation on private property is not under a conservation covenant, there is a risk of unwitting destruction should the property change hands from the present sympathetic owners. The woodland remnant in which the Dodges Ferry subpopulation occurs is also at risk of being cleared arising from pressure to reduce the fire risk to adjacent housing (TSS 2009).

Inappropriate disturbance regime
The Sagg Spider-orchid appears to favour a level of disturbance, being most abundant where ground has been regularly disturbed by animals, in particular, rabbits and horses (Jones et al. 1999, cited in TSS 2009). Establishing suitable habitat by other means, such as burning or selective vegetation removal may be necessary for long-term viability of this species.

Fire and drought
Fire may have played an integral part in maintaining suitable habitat for the Sagg Spider-orchid prior to European settlement when hot summer fires would have occurred. Prolonged lack of fire may lead to a dense crowded understorey that potentially limits recruitment of the species. Inappropriate fire intensity or timing may also impact on the species ability to recruit or recover (TSS 2009).

Rabbit grazing and other browsers
Browsing and digging by rabbits has been observed at the Cambridge site of the Sagg Spider-orchid which will over time lead to a decrease in tubers and numbers of the species. The impacts of native browsers, such as brushtail possums and bandicoots are unknown (TSS 2009).

Stochastic risk
The small restricted nature of both subpopulations increases the risk of decline from unforseen human activities or chance events. The Dodges Ferry subpopulation may not be viable in the longer term given that it is very small (3 plants) and occurs in a very small remnant (0.15 ha), surrounded by roads and residential development (TSS 2009).

Climate change
While the extant population of the Sagg Spider-orchid occurs at a site of naturally low rainfall, even minor shifts in the average seasonal conditions has the potential to further exacerbate the precarious position of the species, particularly if the rainfall pattern changes, which in turn could lead to altered fire regimes (TSS 2009).

A national Flora Recovery Plan: Tasmanian Threatened Orchids 2006-2010 has been adopted (TSS 2006a). This recovery plan outlines actions to manage 68 identified threatened orchids in Tasmania, 20 of which are listed under the EPBC Act. Actions include (TSS 2006a):

  • Acquiring accurate information for sound management decisions and conservation status assessments.
  • Ensuring priority populations are managed appropriately and are securely protected.
  • Increasing the number of known populations of threatened orchid taxa.
  • Raising public awareness of orchid conservation issues and develop mechanisms to encourage and coordinate community participation in orchid recovery programs.
  • Establishing a network of government and non-government organisations and individuals that can provide input into recovery programs and undertake recovery actions.
  • Developing a better understanding of the life history and ecological requirements of threatened orchids in Tasmania.
  • Increasing the size of priority populations in the wild.
  • Identifying critical and potential habitat.
  • Establishing a genetically representative ex situ collection of orchid taxa facing imminent extinction in the wild.

To increase understanding of the Sagg Spider-orchid along with other Tasmanian orchids in order to protect populations, DPIWE and the volunteer Tasmanian Threatened Plant Action Group (TPAG) are undertaking long-term annual monitoring of the known population to provide information with which to assess recovery actions. DPIWE is also working with landowners on whose land the Sagg Spider-orchid exists to mitigate threats (Larcombe 2008, TSS 2009).

A gated fence has also been erected at the Cambridge subpopulation for specific periods to protect the species from grazing pressure from rabbits (TSS 2009).

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
Agriculture and Aquaculture:Agriculture and Aquaculture:Land clearing, habitat fragmentation and/or habitat degradation Contributions to Tasmanian Orchidology 1-9. Australian Orchid Research. 3. (Jones, D.L., 1998d) [Journal].
Commonwealth Listing Advice on Caladenia saggicola (Sagg Spider-orchid) (Threatened Species Scientific Committee, 2001as) [Listing Advice].
Climate Change and Severe Weather:Sea level rise:Inundation associated with climate change Inundation study (Environmental Resources Information Network, 2007) [Database].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Commonwealth Listing Advice on Caladenia saggicola (Sagg Spider-orchid) (Threatened Species Scientific Committee, 2001as) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Predation, competition, habitat degradation and/or spread of pathogens by introduced species 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:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Commonwealth Listing Advice on Caladenia saggicola (Sagg Spider-orchid) (Threatened Species Scientific Committee, 2001as) [Listing Advice].
Species Stresses:Indirect Species Effects:Low numbers of individuals Species threats data recorded on the SPRAT database between 1999-2002 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012i) [Database].
Commonwealth Listing Advice on Caladenia saggicola (Sagg Spider-orchid) (Threatened Species Scientific Committee, 2001as) [Listing Advice].

Council of Heads of Australasian Herbaria (CHAH) (2005). Australian Plant Census. [Online]. Australian National Herbarium, Australian National Botanic Gardens and Australian Biological Resources Study . Available from:

Jones, D.L. (1998d). Contributions to Tasmanian Orchidology 1-9. Australian Orchid Research. 3. Essendon, Victoria: Australian Orchid Foundation.

Jones, D.L. (2001). Personal Communication.

Jones, D.L., H. Wapstra, P. Tonelli & S. Harris (1999). The Orchids of Tasmania. Carlton South, Victoria: Melbourne University Press.

Jones, D.L., M.A. Clements, I.K. Sharma & A.M. McKenzie (2001). A new classification of Caladenia R.Br. (Orchidaceae). The Orchadian. 13(9):389-417.

Larcombe, M. (2008). Tasmanian Threatened Orchid Baseline Data and Monitoring: Where we are at and where we need to be. The Tasmanian Naturalist. 130:67-81.

Threatened Species Section (2009). Listing Statement for Caladenia saggicola (sagg spider-orchid). [Online]. Available from:$FILE/Caladenia%20saggicola%20LS.pdf. [Accessed: 04-May-2010].

Threatened Species Section (TSS) (2006a). Flora Recovery Plan: Tasmanian Threatened Orchids 2006-2010. [Online]. Hobart, Tasmania: DPIWE. Available from:

EPBC Act email updates can be received via the Communities for Communities newsletter and the EPBC Act newsletter.

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 saggicola in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: Accessed Fri, 19 Sep 2014 06:18:47 +1000.