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 huegelii
Recovery Plan Decision Recovery Plan required, included on the Commenced List (1/11/2009).
 
Adopted/Made Recovery Plans Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan] as Caladenia huegelii.
 
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 huegelii.
 
Amendment to the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (11/04/2007) (Commonwealth of Australia, 2007f) [Legislative Instrument] as Caladenia huegelii.
 
State Government
    Documents and Websites
WA:Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].
State Listing Status
WA: Listed as Critically Endangered (Wildlife Conservation Act 1950 (Western Australia): September 2013 list) as Caladenia huegelii
Scientific name Caladenia huegelii [7309]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author H.G.Reichb.
Infraspecies author  
Reference Beitrage zur Systematischen Pflanzenkunde (1871) 66
Other names Caladenia sp. 1 (S.Swan Coastal Plain) [24376]
Caladenia huegelii Hopper & Brown ms. [67399]
Caladenia huegelii Hopper & A.P.Brown ms. [67436]
Arachnorchis huegelii [76607]
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.biosurvey.ou.edu/bebb/mia/calad_hueg2.jpg

Scientific name: Caladenia huegelii

Common name: King Spider-orchid

Synonyms: Calonema huegelii, Arachnorchis huegelii, Calonemorchis huegelii

Other common name: Grand Spider-orchid, Rusty Spider-orchid

The King Spider-orchid has been subject to some dispute regarding its taxonomic placement (Hopper & Brown 2001b, 2004; Jones et al. 2001; Szlachetko 2001a), nevertheless, the name Caladenia huegelii has been accepted by the Council of Heads of Australia Herbaria (CHAH 2005).

Historically, the King Spider-orchid was confused with other closely related species, leading to the impression that the species was widely dispersed with highly variable characteristics (Hopper & Brown 2001b; Stoutamire 1983). Much of this confusion originates from a mixed collection on the type sheet, now identified as also containing Caladenia paludosa and C. ensata specimens (Hopper & Brown 2001b).

The King Spider-orchid is a slender orchid, usually growing 30–70 cm high but occasionally up to 1 m (Williams et al. 2001). It has one or two striking flowers characterised by a greenish-cream labellum (the largest, lower petal) with a maroon tip that curves backward (recurved). It has a long fringe that is often branched at its tips and extends well above the column (the reproductive structure in the centre of the flower) (Williams et al. 2001). The sepals and petals are cream with red or pink suffusions and these sepals have narrow, brown, terminal clubs. The hairy, linear leaf may be up to 40 cm long and the flowers are larger than most similar species (Brown et al. 1998). The above-ground portions of the plant die back to underground tubers over summer (Kelly et al. 1993).

The King Spider-orchid typically occurs as a solitary plant and rarely grows in loose clumps (Hopper & Brown 2001b).

General distribution
The King Spider-orchid occurs in scattered localities within 20 km of the coast, from the Upper Swan and Gnangara areas north of Perth, through suburban Perth and southwards to Gracetown and the Scott River in the Margaret River area of Western Australia (Brown et al. 1998; Hopper & Brown 2001b; Hopper et al. 1990; Kelly et al. 1993). The largest population occurs at Jandakot, south of Perth (WA DEC 2009e).

Extent of occurrence and area of occupancy
The King Spider-orchid's range is more than 300 km within 20 km of the coast (WA DEC 2009e; Williams et al. 2001) and its area of occupancy is estimated to be less than 10 km² (Main Roads 2004). However, since these estimates, further populations have been discovered (ATA Environmental 2003a, 2003b; Maunsell 2004; WA DEC 2006) that may increase area of occupancy.

The King Spider-orchid was probably once common on the Swan Coastal Plain (Hopper & Brown 2001b; WA DEC 2009e), but extensive urban and agricultural clearing has reduced its area of occupancy and it is now restricted to remnant bushland. Preferred habitat of the species overlaps with the main areas of urban development that occur between Perth and Bunbury (DEWHA 2009e). Urban development within the Perth Metropolitan Region is known to have substantially impacted upon 10% of the known populations and has caused the disappearance of at least seven previously known populations (ATA Environmental 2003a).

Population numbers and fragmentation
It is estimated that the King Spider-orchid occurs in 33 populations, in three major aggregations (Main Roads 2004; WA DEC 2006, 2009e). Due to fragmentation of the species' habitat each population may be considered to be removed from each other (Bland & Brown 2004). The distribution of the King Spider-orchid is severely fragmented due to urban and rural development (Main Roads 2004).

Ex situ populations
The King Spider-orchid has been successfully propagated at Kings Park Botanic Gardens, Perth. Translocations have been proposed for Lot 106 Wright Road (ATA Environmental 2003a), and another for the Roe Highway Stage 7 (Hart, Simpson & Associates 2002; Maunsell 2004), however, the status of these proposals is unknown.

Several surveys for the King Spider-orchid have been conducted by the Western Australian Department of Environment and Conservation (WA DEC) and by environmental contractors for development projects (ATA Environmental 2003a, 2003b; Maunsell 2004). However, further research is required to obtain a comprehensive estimate of population size and condition (ATA Environmental 2003a).

Total population size
The King Spider-orchid is known from 33 extant populations with a total of 1614 mature plants. Seventeen of the 33 populations occur as less than five flowering plants (DEWHA 2009e). Many of the smaller populations have had seasons where no flowers were recorded during the flowering period (DEWHA 2009e), which is probably the result of weather conditions. Eighty-five percent of plants have been recorded from four populations at Jandakot (up to 800 plants, one large population over two properties), Banjup (200–400 plants) and Coolup (up to 350 plants) (DEWHA 2009e).

Population structure
The King Spider-orchid was probably common prior to land clearing but now occurs primarily in small populations (Hopper & Brown 2001b). No information on genetic exchange between these populations is available. The two main aggregations of this orchid's distribution - the Perth Metropolitan Region and the Central Forest Region - are not thought to be contiguous (Bland & Brown 2004). The third substantial aggregation of this species is found between these areas at Kooljerrenup Nature Reserve and this may represent a linking population between northern and southern areas (WA DEC 2006).

A summary of the three population aggregations is below:

Perth Metropolitan Region
The most recent estimate of population numbers indicates that there are up to 800 plants in the vicinity of the Roe Highway reserve and nearby areas around Jandakot (WA DEC 2009e). It has also been reported that seven populations in the region have gone extinct following urban development (ATA Environmental 2003a), and a number of formerly known populations remain to be surveyed to confirm their status (Main Roads 2004).

Kooljerrenup Nature Reserve
A 2005 survey for the King Spider-orchid at Kooljerrenup Nature Reserve near Coolup and Pinjarra (89 km south of Perth) uncovered a substantial population (The Canberra Times 2006; WA DEC 2006), which is now estimated at 350 plants (WA DEC 2009e).

Central Forest Region
South of the Perth Metropolitan Region and the Kooljerrenup Nature Reserve, the King Spider-orchid has been recorded from at least 13 sites which include national park, state forest and flora and fauna reserves in the Central Forest Region. Many of these southern populations are small, and contain less than 10 plants (Williams et al. 2001). These populations are relatively isolated and fragmented due to much of the surrounding habitat being cleared for agriculture and urban development (Bland & Brown 2004).

Population fluctuations
Records of individual populations from year-to-year can be quite variable, as it is thought that the King Spider-orchid does not flower every year, and flowering may be promoted by disturbance to the overstorey canopy. The bulbs of the King Spider-orchid can lie dormant beneath mature trees and shrub canopies until disturbance such as fire or partial clearing occurs (ATA Environmental 2003a).

The King Spider-orchid is known to hybridise with Caladenia longicauda (Bland & Brown 2004; Roe 7 Alliance 2004) and C. pattersonii (Stoutamire 1983).

Within the Perth Metropolitan Region, much of the favoured habitat of the King Spider-orchid has been cleared or is under threat from development (Kelly et al. 1993). Twelve populations in the region are in conservation reserves or Bush Forever sites, and include (ATA Environmental 2003b):

  • Kooljerrenup Nature Reserve
  • Ruabon Nature Reserve
  • Ken Hurst Park Site No. 245
  • Fraser Road Bushland Site No. 390
  • Canning River Regional Park Site No. 224
  • Harnsdale Swamp and adjacent Bushland Site No. 253
  • Acourt Road Bushland Site No. 389
  • Holmes Street Bushland Site No. 125
  • Lowlands Bushland Site No. 368
  • Jandakot Airport Site No. 388
  • Sicklemore Road Bushland Site No. 272
  • Maralla Bushland Site No. 300.

In 2009, 22% of Grand Spider-orchid individuals (363 plants) occurred in nature reserves and a further 12% (196 plants) occurred on land in the process of becoming reserved for conservation (largely as a result of development negotiations). If improved tenure could be negotiated for two populations at Jandakot a further 50% (805 plants) could be secured (WA DEC 2009e).

The King Spider-orchid grows in well-drained, deep sandy soils in low mixed woodlands of Coast Banksia (Banksia attenuata), Firewood Banksia (B. menziesii), Holly-leaved Banksia (Banksia ilicifolia), Western Sheoak (Allocasuarina fraseriana) and Jarrah (Eucalyptus marginata). It tends to favour areas of lush undergrowth (Brown et al. 1998; Hoffman & Brown 1998; Kelly et al. 1993).

The preferred soil conditions are variable and range from wet to moist to dry. The species is killed by fire when flowers or leaves are present and its growth is suppressed by weed invasion (ATA Environmental 2003a; Brown et al. 1998).

South-west Western Australia, where the King Spider-orchid occurs, experiences a Mediterranean climate, with a summer-dry, winter-wet rainfall regime. This species grows typically within 20 km of the coast (Hopper & Brown 2001b). It is known to inhabit winter-wet depressions (Marchant et al. 1987), although in the Central Forest Region it also occurs on low sandy rises (Williams et al. 2001).

The Grand Spider Orchid (Caladenia huegelii) Recovery Plan (WA DEC 2009e) provides detailed biological and ecological information.

Flowering
The King Spider-orchid flowers from September to October and is thought to fruit in the same season. The species dies back to underground tubers over summer (Hoffman & Brown 1992). Plants may not flower each year. However, after disturbance to the canopy, or following summer fire, this species can be found flowering profusely (ATA Environmental 2003a; Hopper & Brown 2001b).

Pollination
A thynnid wasp (Zaspilothynnus) has been recorded as the targeted pollinator for the King Spider-orchid at Windy Harbour and Mt Chudalup near Northcliffe, Western Australia. These wasps are 'deceived' by the orchid through chemical and visual cues produced by the orchid to mimic a female wasp. Male thynnid wasps fly upwind towards the source of the pheromone-like chemical and then visual cues of the flower mimicking the female body are employed (Stoutamire 1983).

For the pollination system to be successful the air temperature needs to be above 20 °C (Stoutamire 1983). At this temperature, the wasps fly actively (Stoutamire 1983) and the flowers emit the chemical attractant (Main Roads 2004). The sky also needs to be cloudless due to the poor vision of the wasps. This combination of factors of warm, clear days is not common during the flowering season due to the high and low pressure fronts that sweep across southern Australia during September and October. These fronts bring cool, cloudy weather, followed by a few days of warm sunny weather before the next front passes (Stoutamire 1983). Thus early in the season, there may only be a few hours each week when the wasps are active (WA DEC 2009e).

Other requirements for these thynnid wasp pollinators of the King Spider-orchid include the presence of superficial nectar sources for feeding, such as flowering Myrtaceae. Zaspilothynus wasp species have been shown to pollinate three Drakea species, but no other Caladenia species (Stoutamire 1983).

Given the specific requirements for King Spider-orchid pollination, successful pollination events do not occur regularly and seed mortality is high. Once fertilised, the orchid capsules produce thousands of tiny seeds, although very few of these seeds are thought to germinate due to their requirement to find a compatible fungal associate where they land (Maunsell 2004). A pollination rate of less then 4% has been reported (WA DEC 2009e).

Myccorhiza
The role of myccorhizal fungi is less well known. Research on the fungal associates of the King Spider-orchid has been undertaken by researchers at Kings Park Botanic Gardens and plants have successfully germinated ex situ (WA DEC 2009e). In situ transplants have also been successful, however, the long-term viability of these plants is unknown (WA DEC 2009e).

The King Spider-orchid is detectable in September to early November during the flowering period (WA DEC 2009e). Distinctively, the labellum of the species contains particularly long, fine, sometimes split fringes, which extend well above the column (Brown et al. 1998).

The Grand Spider Orchid (Caladenia huegelii) Recovery Plan (WA DEC 2009e) outlines threats for the King Spider-orchid.

A lack of suitable habitat
Land clearing has occurred over much of the King Spider-orchid's range and has resulted in severe habitat fragmentation and isolated populations. This has also made it less likely that further populations will be discovered and a limited number of areas suitable for translocation. The small size of remnants also reduces the success of pollination. Urbanisation is likely to increase the severity of fragmentation (WA DEC 2009e).

Habitat degradation
Populations occur in habitat that is becoming increasingly degraded, which leads to reduced capacity for mycorrhizae and pollinating wasps (WA DEC 2009e).

Inappropriate fire regimes
Spring fires (July–November), when this species has leaves or flowers, are likely to kill the King Spider-orchid (ATA Environmental 2003a; Brown et al. 1998; Kelly et al. 1993). However, fires in the tuberous/dormancy phase of the plant's life cycle, in summer and autumn, can initiate flowering the following season (Main Roads 2004). Too frequent fires are likely to be detrimental to the species' habitat (WA DEC 2009e).

Weed invasion
Weeds increase grazing pressure and compete for resources (WA DEC 2009e). Weeds also suppress growth (Kelly et al. 1993) of the King Spider-orchid which is thought to do best in areas of natural vegetation (Main Roads 2004).

Other threats
Other threats include grazing, infrastructure maintenance (road, powerline, rail and firebreak), recreation activities, rubbish dumping, disease and poor recruitment (WA DEC 2009e).

The Grand Spider Orchid (Caladenia huegelii) Recovery Plan (WA DEC 2009e) provides explicit management recommendations. Further recovery actions can be found in Williams and colleagues (2001) and Honczar (2005). Management recommendations include (WA DEC 2009e):

  • coordinate recovery actions
  • liaise with land managers
  • carry out appropriate management of bushland that contains Caladenia huegelii (e.g. disturbance regimes)
  • carry out environmental assessment of developments or actions that have the potential to damage King Spider-orchid plants or habitat
  • seek positive conservation outcomes for future development proposals for lands containing the King Spider-orchid
  • monitor populations
  • increase area of the King Spider-orchid habitat on secure tenure
  • manage access
  • assess and install Declared Rare Flora markers
  • undertake weed control
  • conduct further surveys
  • clarify identification of unconfirmed populations
  • develop and implement a fire management strategy
  • develop and implement a grazing control strategy
  • collect and store seed and fungal material
  • promote awareness
  • manage small populations to increase numbers of individuals and area of occupancy
  • research and develop best practice protocols for translocations
  • plan conservation translocations
  • obtain biological and ecological information (e.g. genetic analysis, susceptibility to Phytophthora dieback, and seed and fungi storage)
  • map habitat critical to survival
  • review the need for further recovery actions.

Orchid germination depend upon mycorrhizal fungi association. Information on research on this association and ex situ cultivation of this species can be found in Batty and colleagues (2001), Bougoure and colleagues (2005) and Brundrett and colleagues (2003).

The King Spider-orchid also depends upon a highly specialised association with male thynnid wasps. This orchid mimics the pheromones and possibly the body of a female thynnid wasp in order to attract male Zaspilothynnus wasps for pollination. This pollination system is known as `sexual deception' and is described by Stoutamire (1983).

There has been much controversy over the taxonomic placement of the King Spider-orchid, originating with mixed specimens on the original herbarium sheet and continuing more recently with three separate and differing taxonomic reviews published in 2001. Some of the key papers have been published by CHAH (2005), Hopper and Brown (2001, 2004), Jones and colleagues (2001), Reichenbach (1871) and Szlachetko (2001a).

Management documents relevant to the King Spider-orchid include:

  • Grand Spider Orchid (Caladenia huegelii) Recovery Plan (WA DEC 2009e)
  • Ken Hurst Park Management Plan (ATA Environmental 2003b)
  • A survey of declared rare flora and other plants in need of special protection of the Scott Plains (Keighery & Robinson 1992)
  • Declared Rare Flora and Other Plants in Need of Special Protection in the Metro Area (Kelly et al. 1993)
  • Declared Rare and Poorly Known Flora in the Central Forest Region (Williams et al. 2001).

Other management suggestions are available in Roe 7 Alliance (2004a), Hart, Simpson & Associates (2002) and Main Roads (2004).

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 Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Biological Resource Use:Gathering Terrestrial Plants:Recreational harvest Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Ecosystem/Community Stresses:Ecosystem Degradation:Decline in habitat quality Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Loss and/or fragmentation of habitat and/or subpopulations Caladenia huegeliiin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006dd) [Internet].
Human Intrusions and Disturbance:Recreational Activities:Disturbance, especially from human recreational activities and development Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Caladenia huegeliiin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006dd) [Internet].
Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Vegetation and habitat loss caused by dieback Phytophthora cinnamomi Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Habitat degradation caused by firebreak construction and/or maintenance Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Caladenia huegeliiin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006dd) [Internet].
Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate prescribed regimes and/or vegetation management to control fire regimes Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].
Pollution:Garbage and Solid Waste:Dumping of household and industrial waste Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Residential and Commercial Development:Commercial and Industrial Areas:Recreational, commercial and industrial development Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Residential and Commercial Development:Housing and Urban Areas:Habitat loss, modification and fragmentation due to urban development Caladenia huegeliiin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006dd) [Internet].
Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Species Stresses:Indirect Species Effects:Low numbers of individuals Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].
Species Stresses:Indirect Species Effects:Poor recruitment (regeneration) and declining population numbers Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Transportation and Service Corridors:Roads and Railroads:Development and/or maintenance of roads Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].
Transportation and Service Corridors:Utility and Service Lines:Powerline easement maintenance and construction; mortality due to collision with powerlines Grand Spider Orchid (Caladenia huegelii) Recovery Plan (Western Australia Department of Environment and Conservation (WA DEC), 2009e) [Recovery Plan].

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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 huegelii in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Wed, 30 Jul 2014 01:19:26 +1000.