THREATENED SPECIES SCIENTIFIC COMMITTEE

Established under the Environment Protection and Biodiversity Conservation Act 1999

The Minister approved this Conservation Advice on 31/10/2019. Conservation Advice Caladenia colorata

Coloured Spider-orchid

Conservation Status

Caladenia colorata (Coloured Spider-orchid) is listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) effective from the 16 July 2000.

The species was eligible for listing under the EPBC Act as on 16 July 2000 it was listed as Endangered under Schedule 1 of the preceding Act, the Endangered Species Protection Act 1992 (Cwlth).

Species can also be listed as threatened under state and territory legislation. For information on the current listing status of this species under relevant state or territory legislation, see http://www.environment.gov.au/cgi-bin/sprat/public/sprat.pl

The main factors that are the cause of the species being eligible for listing in the Endangered category are its restricted extent of occurrence and fragmentation, limited population size and projected decline due to the threats of grazing, weed invasion and habitat degradation.

Description

The Coloured Spider-orchid is a deciduous, perennial, terrestrial orchid emerging annually from an underground tuber that grows 5–25 cm in height. The single leaf is linear-lanceolate, densely felted with a red base and grow to 10 cm in length. Flowers are about 5 cm across, generally cream-green with reddish or purple-brown markings, dark glandular tips to all segments. They are, however, variable and can sometimes be wholly purple-brown, pale cream-green with reddish labellum calli and marginal teeth, to wholly pinkish to dark reddish. The labellum (lip) is a flat, single lobe with an elongated tip that curls under, margins that are shortly fringed-dentate and a mid-lobe that is usually darker. The dorsal is narrow throughout and erect, and the lateral have a broad, flat, almost horizontal base and narrow pendulous tips. are behind the flower and similar to dorsal and lateral sepals but shorter (Bates 2011; Jones 1991b).

Plants from Bangham, Geegeela and Fairview Conservation Parks and the Lower South East ascribed to Coloured Spider-orchid tend to be much larger, with sepals to 60 mm long, and frequent examples of uniformly pinkish to reddish coloured flowers. It is possible that these have been misidentified (Bates pers comm. 2010).

The species is dormant during summer, and dormancy is broken in response to autumn rain, with leaf emergence occurring in late autumn-early winter. The flowering period of the Coloured Spider-orchid extends through August and September in South Australian and from September to October in Victoria (Bates 1992 cited in Obst 2005; DSE 2009). The species is pollinated by sexually attracted male wasps (Bates 2009, 2011).

Distribution

The Coloured Spider-orchid is known from South Australia and Victoria. The historical distribution of this species is unknown, but it is likely to have occurred in southeast South Australia and southwest Victoria (DSE 2009). Generally it is thought to be absent from high rainfall districts (Bates 2009, 2011). South Australian historical records of the species range

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from the Barossa Valley in the north, through the Murray River and Murray Lake flats to the upper south-east of the state. The species is now considered extinct in the Barossa Valley and from Beachport (DENR 2011). Additionally, there is uncertainty as to the correct identification of records from Coorong National Park (NP) and the lower SE of SA extending south from Bangham Conservation Park (CP) (R. Bates pers. comm. 2010).

In Victoria, the species is known from the Lower Glenelg in the state's south-east.

The Coloured Spider-orchid has been observed at 58 sites comprising 28 populations, although currently only 12 populations have been vouchered and only seven are currently confirmed and extant. Data on current population size may be an underestimate, as flowering rates vary from year to year, depending upon rainfall.

Coloured Spider-orchid populations have between 5,000 and 5,700 dependant on seasonal conditions (Table 1).

Table 1 Summary of population location, size, tenure and threats at all known sites.

Sub-pop. Size (flowering plants) Threats Population Vouchered? No. sites Area Manager Maximum Most recent (High Medium Low) count count

CONFIRMED AND Extant EXTANT sites Hartley 1: Y 11 4,102 3864 (2015) 23 private grazing (H); weed private properties (10), (2006) ha AC invasion (M); no formal protection (M) roadside (1) Hartley 2: private Y 6 1,220 1012 (2015) 2.3 private grazing (H); weed properties (5) (2005) ha invasion (M); no formal protection (M) Tailem Bend: private 1 10 (2013) 10 (2013) 2 ha private property Coonalpyn 1: private Y 2 16 (2005) 4 (2006) <0.1 private grazing (H); weed property (1) ha invasion (M) Coonalpyn 2: 1 209 1 (2006) <0.2 private weed invasion (M); no private property (1), (2005) ha CDC formal protection (M); roadside (1) disturbance/destruction (M) Mt Boothby CP 1 28 (2005) 20 (2006) <0.1 DEW ha Padthaway CP 1 2 (2005) DEW NOT SEEN IN ≥14 Recorded YEARS sites Monarto CP Y 1 0 (2005) 0 (2005) DEW Langhorne Ck: private 1 0 (2004) 0 (2004) private property (1) Milang: private Y 4 0 (2004) 0 (2004) private grazing (H); weed properties (3), reserve FoN invasion (M); no formal (1) protection (M) Clayton: private 1 ? (1991) ? (1991) private property (1) Mt Monster CP Y N/A not seen for DEW many yrs Desert Camp CP N/A ? (2005) DEW UNCERTAIN Recorded IDENTITY sites Coorong National 12 273 31 (2006) <0.3 DEW grazing (H); weed Park (2005) ha invasion (M) Potters Scrub Bangham CP Y N/A 230+ 65 (2009) 4 DEW grazing (L); (2004) sites disturbance/destruction (L) Near Bangham 1: N/A private private property (1) Caladenia colorata (Coloured Spider-orchid) Conservation Advice Page 2 of 8

Sub-pop. Size (flowering plants) Threats Population Vouchered? No. sites Area Manager Maximum Most recent (High Medium Low) count count

Near Bangham 1: N/A private private property (1) Geegeela CP N/A 330+ 205 (2009) 6 DEW weed invasion (L); (2003) sites disturbance/destruction (L) Mt Scott CP N/A ? (1999) DEW Fairview CP Y N/A DEW Naracoorte: private N/A ? (1999) private property (1) Spence – Coles Rd N/A 60 60 NLC (estimate) (estimate) (2007) (2007) Big Heath CP N/A (1999) DEW Penola – Lucindale Rd N/A <20 <20 (1999) WRC (1999) Kongorong: private Y N/A private property (1) Glenelg CP Y N/A DEW EXTINCT Kapunda: private Y private Extinct (only record property (1) 1979) Beachport Y N/A Extinct (only record 1923) (Bickerton 2018. pers. comm 6 December 2018; Moritz 2018. pers. comm. 6 December)

In 2015, total number of known plants over the seven confirmed and extant populations was up to 5,000 plants in the South Australian Murray-Darling Basin region (Moritz pers. comm. 2018). The most significant population is ‘Hartley 1’, containing between 3,900 and 4,100 individual plants in an area of approximately 0.23 km 2. In Victoria the species is known from one wild population containing approximately 150 plants (DSE 2009).

The seven confirmed and extant populations extend across 18 privately owned properties, two Conservation Parks and two council-managed roadsides. Three populations extend across multiple land tenures). Five of the privately owned properties are under Heritage Agreement (a legal contract, registered on the property title, between the landowner and the South Australian Government to protect native vegetation in perpetuity).

Relevant Biology/Ecology

Little is known about the biology and ecology of the Coloured Spider-orchid. The species is dormant during summer, and dormancy is broken in response to autumn rain, with leaf emergence occurring in late autumn early winter. The plants flower from late August to early October, and the flowers remain open for a few days to a few weeks, depending on pollination and climatic conditions. Fruits usually take 5 to 8 weeks to mature following pollination, and plants reproduce solely from seed. The average longevity of Coloured Spider-orchid plants is not known. The species grows in a complex relationship with a mycorrhizal fungus that initiates seed germination, and assimilates some nutrients for the orchid. The type and degree of dependence upon the fungus, particularly of mature plants, is not known. Pollination is probably via sexual deception through the process of pseudocopulation (Peakall & Beattie 1996), with the pollinator being a black thynnid wasp (NOSSA 2011). Plants freely hybridise with other co- occurring Caladenia species including Thick-lipped Spider-orchid ( C. cardiochila ), Starry Spider- orchid (C. stellata ) and Mallee Spider-orchid (C. verrucosa ) (NOSSA 2011).

In South Australia the Coloured Spider-orchid grows in sandy, fertile soils but also in rock outcrops and in mallee/broombush associations (Bates 2009). This species grows in woodland dominated by Eucalyptus leucoxylon (South Australian Blue Gum), E. fasciculosa (Pink Gum),

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E. porosa (Black Mallee Box), Allocasuarina verticillata (Drooping Sheoak) and Callitris gracilis (Southern Cypress Pine) (Bates 2011; DENR 2011; Jones 1991b)

The Painted Spider-orchid occurs in the following habitats (Obst 2005):

• Eucalyptus leucoxylon subsp. leucoxylon +/- E. fasciculosa +/- Callitris gracilis Woodland

Native mid-storey species of this association include Golden Wattle ( Acacia pycnantha ), Broom Baeckea ( Baeckea behrii ) and Sweet Bursaria ( Bursaria spinosa ). Native understorey species of this association include Austrostipa sp., Dianella revoluta var. revoluta, Twiggy Guinea- flower (Hibbertia virgatus ), Kunzea pomifera, Sticky Sword Sedge ( Lepidosperma viscidum ), Yam Daisy ( Microseris lanceolata ) and the Paper Flower ( Thomasia petalocalyx ) (Obst 2005) .

• Eucalyptus fasciculosa +/- E. porosa +/- Callitris gracilis Open Woodland

Native mid-storey species of this association include Reed-leaf Wattle ( Acacia calamifolia ), Hedge Wattle (Acacia paradoxa ), Sweet Bursaria, Mallee Honeymyrtle ( Melaleuca acuminata ) and Broom Honeymyrtle ( Melaleuca uncinata ). Native understorey species of this association include Chocolate Lilly (Arthropodium strictum ), Austrostipa spp., Scented Sundew ( Drosera whittakeri ), Heathy Saw-sedge (Gahnia deusta ), Sticky Sword Sedge, Scented Mat-rush (Lomandra effusa ) and the Yam Daisy (Obst 2005).

• Eucalyptus diversifolia +/- Acacia pycnantha +/- Allocasuarina verticillata +/-Myoporum insulare Mallee Woodland

Native mid-storey species of this association include Dodonaea viscosa subsp. s patulata , Black Paperbark (Melaleuca lanceolata ) and Sand-heath Yacca ( Xanthorrhoea caespitosa ). Native understorey species of this association include Dianella revoluta var. revoluta, Beaked Hakea (Hakea rostrata ), Silky Guinea-flower (Hibbertia sericea ), Black Rapier-sedge ( Lepidosperma carphoides ), Sticky Sword Sedge, Yam Daisy and the Paper Flower (Obst 2005).

In Victoria the Coloured Spider-orchid occurs in an open area in low, mixed Swamp Gum (Eucalyptus ovata ) / Brown Stringybark ( E. baxteri ) / Messmate Stringybark ( E. obliqua ) woodland. The heathy understorey contains Prickly Moses ( Acacia verticillata ), Myrtle Wattle ( A. myrtifolia), Flame Heath ( Astroloma conostephioides ), Horny Conebush ( Isopogon ceratophyllus ), Sweet Bursaria ( Bursaria spinosa ), Moonah ( Melaleuca lanceolata ), Sticky Hop- bush ( Dodonaea viscosa ) and sedge species. The population is growing on calcarious sands and sandy loams derived from limestone, with areas of exposed limestone rock.

Threats

The Coloured Spider-orchid is at risk from a combination of threats across its locations in South Australia and Victoria, including grazing, invasive weeds and habitat disturbance. Risk posed by each of these threats may vary depending on geographical, environmental, biological and sociological factors.

Table 1 – Threats impacting the painted spider-orchid in approximate order of severity of risk, based on available evidence.

Number Threat factor Threat type Evidence base and status 1.0 Grazing 1.1 Grazing by Known/Current Stock grazing is a known threat to at least domestic animals one population (Obst 2005). Sheep may also cause compaction of soil around individuals and an increase in nutrients from

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manure (Cropper 1993). Soil compaction can reduce the ability of seedlings to penetrate the soil and germinate, whilst an increase in nutrients may facilitate the spread of weed seeds or be detrimental to some vegetation types (Cropper 1993). 1.2 Grazing by feral Known/Current Grazing can have a devastating impact on and native orchids (Duncan et al., 2005). The nipping species off of leaves and flowers is threatening a number of populations of the Coloured Spider-orchid, and is caused by rabbits (Oryctolagus cuniculus ), kangaroos (Macropodidae sp.) and invertebrates (Obst 2005). The largest population located at Hartley is being significantly impacted by an increasing kangaroo population. 2.0 Invasive weeds 2.1 Weed invasion Known/Current Weed invasion is a known threat to the Coloured Spider-orchid. Weeds directly out- compete orchids for resources and change the vegetation type and structure of the habitat. They can also alter microhabitats, which may indirectly cause a negative impact on orchid species (Duncan et al. 2005). Perennial Veldt Grass ( Ehrharta calycina ) and Bridal Creeper ( Asparagus asparagoides ) in particular have effected Coloured Spider-orchid populations (Obst 2005). Both these weeds can dominate the understory, compete with mature plants and inhibit the establishment of new growth (Jusaitis 1991). 3.0 Habitat loss, modification, disturbance and fragmentation 3.1 Utility clearance Known/Current Incremental clearance for activities including (eg roads and road works, fire management, fence maintenance construction are considered a significant activities) threat to threatened populations and a current but low threat to this species (Obst 2005). These activities can trample, crush, slash or compact plants and / or soils, and cause chemical spray damage to plants and degrade their habitat. 3.2 Recreational Known/Current Recreational activities, such as horse riding, activities can cause destruction of, and physical damage to plants (e.g. trampling, crushing, uprooting); soil compaction; soil disturbance, affecting soil moisture and encouraging the establishment of weeds and the degradation of habitats (DEH 2009). 3.3 Change in land Likely/Historic Clearance of woodland for agricultural use is use - agriculture a likely historic threat. Woodland that appears to be the preferred habitat of the Coloured Spider-orchid has been historically cleared for agricultural and other use, Caladenia colorata (Coloured Spider-orchid) Conservation Advice Page 5 of 8

resulting in isolated habitat patches. It is likely that the orchid has been impacted by this clearing. At least one site of known occurrence has been cleared, with no specimens of the species found subsequently (DENR 2011). 3.4 Lack of formal Known/Current Of the 18 privately owned properties with protection to confirmed and extant subpopulations of mitigate human Coloured Spider-orchid, only 5 have activities Heritage Agreements. At sites on private land without Heritage Agreements or other formal protection mechanisms, the species is still at risk from grazing, recreational activities, weed spraying or vegetation clearance. The species has been recorded from conservation reserves, although there is only recent population data for Mt Boothby CP and Padthaway CP (DENR 2011).

Conservation Actions

Conservation and Management priorities Grazing

o Ensure land managers use an appropriate grazing regime that does not detrimentally affect the Coloured Spider-orchid, including consideration of exclusion. This action is linked to 1.1 in the Threats table. o Manage total grazing pressure. Use of exclusion fencing and other barriers may be used to exclude grazing by herbivores such as rabbits and kangaroos. This action is linked to 1.1 and 1.2 in the Threats table. o Control rabbits using appropriate methods in accordance with the ‘Threat abatement plan for competition and land degradation by rabbits’ (refer to DoEE 2016), which may include undertaking a range of control techniques (e.g. poisoning and warren destruction). This action is linked to 1.2 in the Threats table. Invasive weeds

o Collaborate with public and private land managers to control and reduce the spread of invasive species, including Perennial Veldt Grass and Bridal Creeper. This action is linked to 2.1 in the Threats table. o Determine and apply the most appropriate physical or chemical control methods for these weeds that will not have a detrimental effect on the Coloured spider-orchid. This action is linked to 2.1 in the Threats table. Habitat loss, disturbance and modifications

o Ensure public and private land managers are aware of the presence and location of the spider-orchid on their land and provide protection measures against known and potential threats to the species, including clearance. This action is linked to 3.0 in the Threats table.

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o Manage road maintenance activities to ensure the protection of the spider-orchid (for example, ensure that stockpiles and machinery parking are located away from known locations of the species). This action is linked to 3.1 in the Threats table. o Manage access to known locations of the spider-orchid to prevent the accidental trampling or destruction of plants by people or off-road vehicles. This action is linked to 3.2 in the Threats table. o Erect signage where appropriate to ensure awareness of presence of the species. This action is linked to 3.3 in the Threats table. o Obtain formal protection of sites on private land through Heritage Agreements. This action is linked to 3.4 in the Threats table. Seed collection, propagation and other ex situ recovery action

o To manage the risk of losing genetic diversity, undertake appropriate seed and mycorrhizal fungi collection and storage in appropriate institutions, such as the Royal Botanic Gardens Victoria and the Australian PlantBank, South Australian Seed Conservation Centre, Australian Botanic Garden, Mount Annan, and determine viability of stored seed. Seeds from all natural populations to be collected and stored. o Establish plants in cultivation in appropriate institutions such as the Royal Botanic Gardens Victoria and Adelaide Botanic Gardens.

Stakeholder Engagement

• Identify partners including traditional owners, landholders, community-based organisations and conservation management organisations that may be associated with recovery of the spider-orchid. • Promote opportunities for partners to participate in activities that will enable the recovery of the spider-orchid, as appropriate.

Survey and Monitoring priorities

• Undertake survey work when plants are flowering in August and September, in suitable habitat and potential habitat to locate additional occurrences, and obtain information on population size, trends, and area of occurrence. Establish baselines for any new populations. • Monitor the progress of recovery, including the effectiveness of management actions and adapt these actions if necessary. • Opportunities to monitor after planned and unplanned fires should be undertaken where they occur in order to understand the fire response of this species.

Information and Research priorities

• Investigate options for linking, enhancing or establishing additional populations. • Investigate reproductive status, longevity, fecundity and recruitment levels for this species and adjust conservation actions as required. • Undertake seed germination and/or vegetative propagation trials to determine the requirements for successful establishment. • Undertake research into pollinator activity and the ecological requirements to support pollinator communities of the painted spider-orchid.

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References cited in the advice

Bates, R. (2009). South Australian Native Orchids . Compact Disc. Adelaide: Native Orchid Society of South Australia. Bates, R.J (2011). South Australia's Native Orchids . Compact disc. Native Orchid Society of South Australia. Cropper, S.C. (1993). Management of endangered plants. CSIRO Publications Department of Environment and Natural Resources (2011). National Recovery Plan for the Coloured Spider-orchid Caladenia colorata . Draft. Department of Environment and Natural Resources, South Australia. Department of Environment and Heritage (2009). Regional Recovery Plan for Threatened Species and Ecological Communities of Adelaide and the Mount Lofty Ranges, South Australia 2009-2014. Department of Environment and Heritage, South Australia. Department of Sustainability and Environment (2009). Action Statement No. 245. Colourful Spider-orchid Caladenia sp. aff. colorata (Lower Glenelg River) Victoria. Department of the Environment and Energy (2016). Threat abatement plan for competition and land degradation by rabbits. Department of the Environment and Energy, Canberra, Australia. Duncan, M., Pritchard, A. & Coates, F. (2005). Major Threats to Endangered Orchids of Victoria, Australia. Selbyana 26, 189–195 Jones, D.L. (1991b). New Taxa of Australian . Australian Orchid Research . 2. Essendon: Australian Orchid Foundation. Jusaitis, M. (1991). Recovery Plans. ANPWS Endangered Species Program Project # 151 . Black Hill Flora Centre, South Australia. NOSSA (2011). South Australian Orchids ebook (ed. by R.J. Bates). Native Orchid Society of South Australia Inc., Adelaide. Obst, C. (2005). South Australian Murray Darling Basin Threatened Flora Recovery Plan . Report to the Threatened Species and Communities Section, Australian Government Department of the Environment and Heritage, Canberra. Available from: http://www.environment.sa.gov.au/files/542b195d-5854-46d1-aeb7- 9e3701172106/SAMDB_Thr_Fl_Rec_Plan_05Jun.pdf. Peakall, R. and Beattie, A.J. 1996. Ecological and genetic consequences of pollination by sexual deception in the orchid Caladenia tentaculata . Evolution 50(6): 2207 2220.

Other sources cited in the advice

Bickerton, Doug (2018) Personal communication. 6 December 2018. Ecologist, Department for Environment and Water, South Australia Government.

Moritz, Kylie (2018) Personal communication. 6 December 2018. Ecologist, Department for Environment and Water, South Australia Government.

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