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 orientalis
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 Arachnorchis orientalis.
 
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 fragrantissima subsp. orientalis.
 
Amendment to the list of threatened species under section 178, 181 and 183 of the Environment Protection and Biodiversity Conservation Act 1999 (Cth) (160) (Commonwealth of Australia, 2014h) [Legislative Instrument] as Caladenia orientalis.
 
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
VIC: Listed as Threatened (Flora and Fauna Guarantee Act 1988 (Victoria): May 2014 list) as Caladenia fragrantissima subsp. orientalis
Scientific name Caladenia orientalis [83410]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author (G.W.Carr) Hopper & A.P.Br.
Infraspecies author  
Reference Hopper, S.D. & Brown, A.P. (2004) Robert Brown's Caladenia revisited, including a revision of its sister genera Cyanicula, Ericksonella and Pheladenia (Caladeniinae: Orchidaceae). Australian Systematic Botany 17(2): 195-196 [comb. nov.]
Other names Caladenia fragrantissima subsp. orientalis [23873]
Arachnorchis orientalis [76200]
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
http://www.edit.ne.jp/~fkoichi/ophoto/aust/calafrag.htm

Scientific name: Caladenia orientalis

Common name: Eastern Spider Orchid

Jones and colleagues (2001) reviewed the genus Caladenia and reclassified Caladenia fragrantissima subsp. orientalis is as Arachnorchis orientalis. Although Hopper and Brown (2004) considered this specific rank appropriate, they recommend the retention of the genus Caladenia to reflect the concept in the original description the species as Caladenia orientalis.

The Eastern Spider Orchid grows to 20 cm tall and has strongly perfumed, creamy white to pale yellowish green flowers (Backhouse & Jeanes 1995).

The Eastern Spider Orchid is a Victorian endemic confined to the Gippsland Plain Natural Region (Conn 1993) between Port Campbell and Yarram (Duncan et al. 2004). Populations are known from Wilson Promontory National Park, Wonthaggi Heathlands Nature Conservation Reserve (two sites), Cape Liptrap Coastal Park, Port Campbell and Cape Paterson (private property) (Duncan et al. 2004). Collections have also been made from Toora, Hedley and Rosebud (private property, Mornington Peninsula) (Jeanes 2001 pers. comm.; Todd 2000).

Previously the Eastern Spider Orchid occurred in near coastal habitats extending from the eastern shores of Port Phillip Bay (Carr 1991). Records for Tasmania (Freycinet Peninsula) need to be confirmed (Carr 1991; Jeanes 2001 pers. comm.). The Port Campbell population may be a misidentification (Duncan et al. 2004).

The Eastern Spider Orchid was surveyed in 2000 and 2005 (Coates & Duncan 2007, 2009). There are ongoing monitoring surveys at both Wilson Promontory and Wonthaggi Heathlands however there are no available data (Duncan 2011 pers. comm.).

In 2004, the total population size for the Eastern Spider Orchid was reported to be 350 plants at six sites (Duncan et al. 2004). Wilsons Promontory and Wonthaggi populations are the largest populations (Duncan et al. 2004). Populations on the Mornington Peninsula and the Yarram-Hedley area may be extinct (Duncan et al. 2004).

Since 2000, some populations have increased and this trend is dependant upon periodic fire and protection from grazing (Duncan 2011 pers. comm.). In one study, surveys between 2000 and 2005 revealed that the cumulative size of two populations increased from 21 to 100 individuals and from 35 to 86 individuals (Coates & Duncan 2009). The increases in population size were mainly due to additional adult plants being found that had presumably been dormant in the first year of the study, with very little of the cumulative total attributed to seedling recruitment (<15% and <5% for the two populations) (Coates & Duncan 2009).

The Eastern Spider Orchid grows in coastal heathland and heathy woodland on deep siliceous sands (Todd 2000).

The Eastern Spider Orchid plants have one or two flowers between October and early November with fruits between November and December (Todd 2000). There is a strong flowering response in the years following fire (Todd 2000). Pollination is likely by male thynnid wasps through pseudocopulation (Todd 2000). There appears to be a cost to reproduction in Eastern Spider Orchid plants, with fruiting plants showing a significant decline in size in the following year. Flowering plants (grazed or not) were also smaller in the following year although the difference between the years was not significant. Non-fruiting plants were more or less the same size from one year to the next (Coates & Duncan 2009).

Recruitment in spider orchids (Caladenia spp.) is entirely from seed, which usually ripen and disperse four to eight weeks after flowering. Plants produce a single replacement tuber each year (Jeanes 2001 pers. comm.). Coates and Duncan (2009) found that rates of flowering or non-reproductive states were high, the seed capsule development rate was low (although within expected range) and seedling recruitment was rare. Fewer than 15% of recorded plants were estimated to be dormant each year (Coates & Duncan 2007). Prolonged dormancy was rare with 50% of dormant periods lasting only a year (Coates & Duncan 2007).

The restriction of mycorrhizal associates of endangered Caladenia species, including Eastern Spider Orchid, to a single ITS (internal transcribed spacer) clade may limit their capacity to establish new populations and retain their distribution. Further research into whether restricted mycorrhizal compatibility is an inherent characteristic of these species or if they lack the opportunity to form associations with a wider range of fungi is needed (Wright et al. 2010).

Arachnorchis x variabilis (formerly known as Caladenia variabilis) is an apparent natural hybrid between the Eastern Spider Orchid and the Thick-lipped Spider-orchid (Caladenia tessellata) from south-east Victoria (Jeanes & Backhouse cited in Jeanes 2002).

Monitoring procedure

While undertaking monitoring, Coates and Duncan (2007, 2009) ran permanent transects through the longest axis of two known orchid populations. A steel pin was inserted 2 cm to the west of each plant for redetection. Each pin had an inscribed anodised aluminium tag and the coordinates (distance along the transect x distance to the plant) of each plant were recorded (Coates & Duncan 2007, 2009).

Sites were revisited annually and the site was actively searched for new plants. Life state categories were recorded during flowering and in early November after capsules had developed. Sterile plants were assumed to be adults unless they were less than 10 cm high and 1 mm wide and not observed in any previous year (Coates & Duncan 2007, 2009).

Plants were assigned to one of the following categories: 1st year seedling, 2nd year seedling, vegetative, flowering, fruiting or dormant. Dormancy was determined retrospectively when a plant re-appeared after a year or more of absence. Individuals that were still not observed at the end of the census period were assumed to be either alive but in an unobservable state (i.e. dormant), or dead. Other plant attributes measured were: leaf width and flowering stem height, and any evidence of grazing or other damage (Coates & Duncan 2007, 2009).

Urban and industrial development has led to habitat destruction in the Eastern Spider Orchid and the near-coastal habitat that it occurs in. Populations occur in areas close to, and within, urban areas (Todd 2000). The following table outlines threats, and the risk of threats, to the Eastern Spider Orchid (Todd 2000):

Threat Risk Comments
Weed invasion Medium Largest threat from Coast Tea-tree (Leptospermum whitei), Coast Wattle (Acacia longifolia subsp. sophorae) and Maritime Pine (Pinus pinaster).
Grazing Low There are no known grazing pressures.
Inappropirate fire regimes High Burning in autumn and winter may be a threat.
Site disturbance Low Sites are largely inaccessible coastal heathland areas, although track slashing may be a threat.
Illegal collection Medium No evidence, but plant numbers are low and close to urban areas.
Other disturbances Medium Slashing of fire breaks may cause soil disturbance; the presence of Cinnamon Fungus should be monitored.
Stochastic event/accidental damage High Total population is less than 100 plants from only a few sites and plant numbers have declined in recent years.

Risk of hand pollination to population fecundity

Results of experiments by Coates and Duncan (2009) suggest that artificially inducing high rates of capsule development by hand pollination may reduce overall population fecundity. Site management that aims to maximise adult survival should be the preferred method to maintain or boost population size, rather than reliance on hand-pollination with a view to in situ cultivation or translocation. Results of the experiments also suggest that avoiding hand-pollination may be particularly important in the long-term absence of fire, or after years when flowering has been prolific. In the latter case, rates of fruit set are likely to be within acceptable ranges, providing that plants are protected from grazing (Coates & Duncan 2009).

The following management actions have been suggested for the Eastern Spider Orchid:

  • Identify and survey potential habitat and continue to monitor known populations (Todd 2000). Monitoring has occurred annually since 2000 (Duncan et al. 2004). The Friends of Wonthaggi Heathlands have undertaken plant surveys and monitoring (Todd 2000).
  • Protect populations on public land at Wonthaggi and Walkerville (Todd 2000).
  • Control high priority weed species at all sites through use of broad-scale habitat management techniques and targeted control of high-risk species (Todd 2000).
  • Investigate grazing impacts by macropods and the Rabbit (Oryctolagus cuniculus) at Wonthaggi after fire (Todd 2000). Cage plants where necessary (Duncan et al. 2004).
  • Implement fine-scale habitat management to encourage seedling establishment (Duncan et al. 2004).
  • Harvest and store seeds (Duncan et al. 2004).
  • Collect vital attribute data following planned fires to determine appropriate fire regimes for habitat and prepare a fire management plan for key populations (Todd 2000).
  • Prepare an orchid introduction plan and establish the species in at least one reserved site in South Gippsland (Todd 2000).

Fire management

The response of Eastern Spider Orchids to fire varies between sites and may be dependant on site characteristics (Coates & Duncan 2009). One population has been recorded as highly responsive to fire, with absence of fire decreasing plant size and number of flowering plants while increasing the number of non-reproductive plants. Following an autumn fire in 2008, a significant increase in plant size occurred (Coates & Duncan 2009). This response may have been due to the impact of fire on inter-specific competition (Coates & Duncan 2009). Another population has been recorded as less responsive and this may be due to the topography of the site (Coates & Duncan 2009).

Variable, rather than fixed, fire frequency prescriptions are likely to be necessary over spatial areas that are in themselves variable (Coates & Duncan 2009). Fire does prevent overabundance of Coastal Tea-tree (Leptospermum laevigatum), however, where Eastern Spider Orchid populations occur close to land for development (Duncan et al. 2004), there is a perception that prescribed fires may escape control lines and damage adjacent properties.

Management documents relevant to the Eastern Spider Orchid can be found at the start of the profile. Other relevant documents include Coates and Duncan (2007, 2009), Duncan and colleagues (2004) and Wright and colleagues (2010).

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:Livestock Farming and Grazing:Grazing pressures and associated habitat changes Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Biological Resource Use:Gathering Terrestrial Plants:Illegal collection Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Human Intrusions and Disturbance:Human Intrusions and Disturbance:Mechanical disturbance during construction, maintanance or recreational activities Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Vegetation and habitat loss caused by dieback Phytophthora cinnamomi 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 and Other Problematic Species and Genes:Predation, competition, habitat degradation and/or spread of pathogens by introduced species 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 and/or habitat degradation Leptospermum laevigatum (Coastal Tea-tree, Victorian Tea-tree) Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
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:Invasion and competition from native plant species Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Natural System Modifications:Fire and Fire Suppression:Habitat degradation caused by firebreak construction and/or maintenance 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) Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
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 twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Residential and Commercial Development:Residential and Commercial Development:Habitat modification (clearance and degradation) due to urban development Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Species Stresses:Indirect Species Effects:Low numbers of individuals Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].
Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004 (Todd, J.A., 2000) [Recovery Plan].
Transportation and Service Corridors:Transportation and Service Corridors:Road and rail maintenance works Caladenia fragrantissima subsp. orientalisin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006db) [Internet].

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

Carr, G.W. (1991). New taxa in Caladenia R.Br., Chiloglottis R.Br. and Gastrodia R.Br. (Orchidaceae) from south eastern Australia. Indigenous Flora & Fauna Association Miscellaneous Papers. 1. Melbourne: Indigenous Flora & Fauna Association.

Coates, F. & M. Duncan (2009). Demographic variation between populations of Caladenia orientalis - a fire-managed threatened orchid. Australian Journal of Botany. 57:326-339.

Coates, F. & M.J. Duncan (2007). Recovery of Caladenia orientalis (eastern spider-orchid) at Wonthaggi Heathland Reserve 2000-2006. Melbourne: Arthur Rylah Institute for Environmental Research.

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.

Duncan, M. (2011). Personal Communication.

Duncan, M., A. Pritchard & J. Todd (2004). Recovery plan for twelve threatened spider orchids (Caladenia R.Br.) in Victoria and South Australia 2005-2009. Melbourne, Victoria: Department of Sustainability and Environment.

Environment Australia (EA) (2001m). Threat Abatement Plan for Dieback Caused by the Root-rot Fungus Phytophthora cinnamomi. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/phytophthora.html.

Hopper, S.D. & A.P. Brown (2004). Robert Brown's Caladenia revisited, including a revision of its sister genera Cyanicula, Ericksonella and Pheladenia (Caladeniinae: Orchidaceae). Australian Systematic Botany. 17:171-240.

Jeanes, J. (2001). Personal communication.

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.

Todd, J. (2004). Flora and Fauna Guarantee Action Statement 103 - Twelve threatened Spider-orchids Caladenia species. [Online]. Victorian Department of Sustainability and Environment, Melbourne. Available from: http://www.dse.vic.gov.au/plants-and-animals/flora-and-fauna-guarantee-act-action-statements-index-of-approved-action-statements.

Todd, J.A. (2000). Recovery Plan for twelve threatened spider orchids Caladenia R. Br. Taxa of Vic and SA - 2000-2004. [Online]. VIC DNRE. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/12-orchid/index.html.

Victoria Department of Sustainability and Environment (Vic. DSE) (2005a). Advisory List of Rare or Threatened Plants in Victoria - 2005. [Online]. East Melbourne, Victoria: Department of Sustainability and Environment. Available from: http://www.dse.vic.gov.au/dse/nrenpa.nsf/93a98744f6ec41bd4a256c8e00013aa9/cfd982b7b4c0bc93ca256fa2007affbc/$FILE/Advisory%20List%20of%20Rare%20or%20Threatened%20Plants%20in%20Victoria%20-%202005.pdf.

Wright, M.M., R. Cross, R.D. Cousens, T.W. May & C.B. McLean (2010). Taxonomic and functional characterisation of fungi from the Sebacina vermifera complex from common and rare orchids in the genus Caladenia. Mycorrhiza. 20:375-390.

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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 orientalis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Mon, 22 Sep 2014 10:02:16 +1000.