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 caesarea subsp. maritima
Recovery Plan Decision Recovery Plan required, included on the Commenced List (1/11/2009).
 
Adopted/Made Recovery Plans Cape Spider Orchid Caladenia caesarea subsp. maritima Recovery plan (Department of Environment and Conservation, 2010) [Recovery Plan] as Caladenia caesarea subsp. maritima.
 
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 caesarea subsp. maritima.
 
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 ceasarea subsp. maritima.
 
Environment Protection and Biodiversity Conservation Act 1999: correction of list of threatened species (28/03/2001) (Commonwealth of Australia, 2001j) [Legislative Instrument] as Caladenia ceasarea subsp. maritima.
 
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 caesarea subsp. maritima
Scientific name Caladenia caesarea subsp. maritima [64856]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author Hopper & A.P.Brown
Infraspecies author  
Reference Hopper, S.D. & Brown, A.P. (2001) Contributions to Western Australian orchidology: 2. New taxa and circumscriptions in Caladenia. Nuytsia 14(1/2): 201-203, Figs 44, 45 (map) [tax. nov.]
Other names Caladenia ceasarea subsp. maritima [64557]
Calonema caesareum subsp. maritimum [78692]
Caladenia caesarea subsp. maritima Hopper & Brown ms. [67268]
Caladenia caesarea maritima Hopper & Brown ms. [67332]
Caladenia caesarea subsp. maritima Hopper & A.P.Brown ms. [67364]
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://florabase.calm.wa.gov.au/browse/profile/13616

The current conservation status of the Cape Spider-orchid, Caladenia caesarea subsp. maritima, under Australian and State Government legislation and international conventions, is as follows:

National: Listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999.

Western Australia: Listed as Declared Rare Flora under the Wildlife Conservation Act 1950.

Scientific name: Caladenia caesarea subsp. maritima

Common name: Cape Spider-orchid

There are two other subspecies of Caladenia caesarea, C. caesarea caesarea and C. caesarea transiens, neither of which overlap the distribution of Cape Spider-orchid.

Cape Spider-orchid is a tuberous, perennial herb which grows to 15–20 cm high and bears one to three flowers with stiffly held petals and sepals. The flowers are mustard-yellow with brown markings and the flowering period is from August to September. The prominent yellow and brown striped labellum (larger lower petal) is thrust well forward before curving down and the margins of the labellum are down-curved. The lateral sepals are 2.3–6 cm long by 2–2.5 mm wide and petals are 2.5–5 cm long. The labellum is 10–15 mm long and 6–9 mm wide. The species grows in shallow soil pockets on coastal granite outcrops (Western Australian Herbarium n.d.; Williams et al. 2001).

Cape Spider-orchid is endemic to Western Australia and is known from six populations located between Dunsborough and the northern tip of Cape Naturaliste within the South West Natural Resource Management (NRM) Region (WA DEC 2007). It is confined to coastal granite areas near Cape Naturaliste over a geographical range of just 5 km, with a northern outlier in Tuart Forest near Ludlow, which has yet to be verified (Hopper & Brown 2001b).

The extent of occurrence is calculated to be 2.92 km². The extent of occurrence was calculated by drawing a boundary around all the known populations to create a polygon. The computer program Arcview GIS and a dataset taken from the Western Australian Department of Environment and Conservation's (WA DEC) Threatened Flora Database (which contains a single GPS coordinate for each population) was used to determine the area of the polygon. There is insufficient data to indicate a decline in extent of occurrence of this restricted species (WA DEC 2007).

As this subspecies is known only from a few scattered localities and is highly restricted, it is possible that the extent of occurrence will decline in future (WA DEC 2007).

The area of occupancy for this species is estimated to be 0.263 km², based on the total area of occupancy of each subpopulation estimated during population monitoring (WA DEC 2007).

There is insufficient data available to show a decline in area of occupancy of this subspecies.

The predictions for the known populations of Cape Spider-orchid are that they should remain stable, as most of the land in which the orchid occurs is relatively undisturbed and the population size has not declined in recent years (WA DEC 2007).

The subspecies is known from six locations and survey in similar habitat has failed to locate any additional subpopulations (WA DEC 2007).

The subspecies distribution is considered to be naturally fragmented as the known populations are scattered with some distances between them (WA DEC 2007).

Cape Spider-orchid was first collected from near Cape Naturaliste by Bruce Maslin in 1972.

There have been three major surveys of this subspecies to date. The results of the first were published in 1994 (Carstairs & Coates 1994). The results of the second survey, which was conducted in August 1997, were published in 2001 (Williams et al. 2001). A third major survey was undertaken in September 2006 (WA DEC 2007).

The subspecies has been surveyed regularly by Western Australian DEC staff at its known locations.


Subpopulation Survey History Number of Plants Recorded Area Condition
1a 09/09/1985
23/09/1986
23/09/1986
06/09/1989
29/09/1993
19/08/1997
30/08/2006
50
common
300
178
178
100
74



24 000 m²


90 000 m²






Healthy
1b 14/09/1989
22/10/1990
29/09/1993
19/08/1997
13/09/2006
50
50
50
20
30
1000 m²



Healthy
1c 14/09/1989
29/09/1993
06/11/1996
12/08/1997
21/08/2001
30/08/2006
91
106
20
100
7
50
10 000 m²




10 000 m²





Healthy
1d 19/08/1997
30/08/2006
12
70

4000 m²

Healthy
1e 28/08/2006 46 900 m² Healthy
2 22/09/1986
06/11/1996
31/08/2006
scarce
0
81


17 500 m²
Moderate

Moderate
3a 09/09/1985
12/08/1997
11/09/2001
29/08/2006

6
57
30


7275 m²
9600 m²

Moderate

Healthy
3b 11/09/2001
22/09/2004
29/08/2006
8
5
90


75 000 m²

Healthy
Healthy
4 14/08/1997
07/09/2000
21/09/2001
22/09/2004
30/08/2006
5
4
0
20
90




27 000 m²
Moderate



Healthy
5 12/08/1997 3   Good
6 22/09/2004
29/08/2006
3
46

4100 m²
Very healthy
Healthy
(WA DEC 2007)

The total population size for this subspecies is 658 mature plants across six locations, some of which are split into subpopulations based upon differences in land tenure and management, as well as location (WA DEC 2007).

All subpopulations appear to be stable. Based on recent survey efforts, the known populations were judged as moderate to healthy, thus indicating an ability to persist for some time into the future (WA DEC 2007).

The subspecies experiences environmental conditions that are cyclical with cool wet winters and hot dry summers. Cape Spider-orchid does not require fire to complete its life cycle and requires protection from frequent inappropriate fire during its active growing phase to prevent loss of plants (WA DEC 2007).

It is thought that adult plants are probably long lived (tens of years or more) but do not flower every year (WA DEC 2007).

All known populations are subject to various threats, including increased fire frequency and weed invasion. Therefore, all known populations would be considered important for the subspecies recovery and long-term survival (WA DEC 2007).


No cross breeding has been recorded for this subspecies.

All known subpopulations, except subpopulation 5 and part of subpopulation 2, occur on Crown Land in Shire Reserves. Although these subpopulations do not fall within the DEC conservation reserve system, they may at some time in the future become incorporated into the DEC reserve system. Subpopulation 5 and part of subpopulation 2 occur on private property (WA DEC 2007).

This subspecies is confined to coastal granite outcrops which have a north-east aspect (Brown et al. 1998; Carstairs & Coates 1994; Hoffman & Brown 1992; Hopper & Brown 2001b). It grows on shallow reddish brown sandy-loam soil that collects in crevices on coastal granite outcrops. The associated vegetation is usually shrubs over low heath, sometimes with scattered small trees (Williams et al. 2001). It is comprised of Acacia pulchella, Boronia tenuis, Calothamnus graniticus subsp. graniticus, C. sanguineus, Cheilanthes tenuissima, Dampiera alata, Darwinia citriodora, Dodonaea ceratocarpa, Dryandra nivea, Eucalyptus calophylla, Gastrolobium spinosum, Hakea trifurcata, H. lissocarpha, Hibbertia hypericoides, H. racemosa, Hypocalymma robusta, Loxocarya flexuosa, Macrozamia riedlei, Nuytsia floribunda, Phyllanthus calycinus, Pimelea ferruginea, Rulingia sp., Trymalium ledifolium, Viminaria juncea and Xanthorrhoea preissii, amongst others (Carstairs & Coates 1994). Occasionally it may be found under dense shrub thickets with Calothamnus graniticus in deeper soils away from the granite (WA DEC 2007). It is also associated with Darwinia sp., Daviesia sp., Hakea sp., Hibbertia sp., Stypandra glauca, and Xanthorrhoea sp. and other low coastal heath species (WA DEC 2007).

Other orchids found with this subspecies include Caladenia chapmanii, C. longicauda, C. gardneri, Cyrtostylis huegelii, Diuris longifolia, Prasophyllum parvifolium, Pterostylis aff. nana and Thelymitra macrophylla (Carstairs & Coates 1994).

The area where the species is found has a temperate climate. The summers (December–March) are hot and dry, and winters are cool and wet. Most rainfall occurs in late autumn, winter and early spring, and the mean annual rainfall at Busselton (some 40 km to the north-east) is 821 mm (Carstairs & Coates 1994).

Cape Spider-orchid shares similar habitat and geographic location with the ecological community Calothamnus graniticus heaths on south-west coastal granites (Meelup Granites) (considered Vulnerable under Western Australian legislation) and are sometimes found to occur at the same site. However, they are not associated, and Cape Spider-orchid is not listed in the flora community list for the Meelup Granites ecological community (WA DEC 2007).

Details on age at sexual maturity, life expectancy and natural mortality of this subspecies are unknown. However, it is believed that plants are probably long lived and flower most years when there has been suitable rainfall (WA DEC 2007).

The flowers are only displayed for 3–10 days and are strongly metallic scented. Pollination is solely dependent on a male thynnid wasp and successful pollination has been shown to be greatly influenced by the prevailing climatic conditions during the brief flowering period, with wasps visiting only during warm weather (Williams et al. 2001).

Flowering occurs from August to September and seed is set in late September to early October. Seed germination relies on the presence of a species specific mycorrhizal fungus. This symbiotic relationship is essential for any seedling establishment. Although very large quantities of seed are released from each capsule, only a fraction germinate and become mature plants (Carstairs & Coates 1994; Williams et al. 2001).

Given the subspecies grows amongst low growing native shrubs and herbs, and sometimes under shrub thickets, it is difficult to see if not flowering. Therefore, surveys should be conducted during the flowering period from August to September (WA DEC 2007).

This subspecies resembles Caladenia caesarea subsp. caesarea in that it has stiffly held petals and sepals, and a prominent yellow and brown striped labellum that is thrust well forward before curving down. However, Cape Spider-orchid differs from the other subspecies of C. caesarea in its smaller flowers with a protruding apex, its coastal granite habitat and its earlier flowering period (Hoffman & Brown 1998; Williams et al. 2001).


Subpopulation ID Past Present Future
All Land clearing Camping/recreation, weed invasion, grazing, trampling, fire, poor recruitment Camping/recreation, weed invasion, grazing, trampling, fire, poor recruitment
1a,b,c,e   Grazing by kangaroos  
2   Grazing by kangaroos  
3a   Trampling  
3b   Grazing by kangaroos and human activity  
2      
4   Grazing by kangaroos  
5     Development
6     Weed invasion
(WA DEC 2007)

In the past, land clearing may have been a threat to a few subpopulations of this subspecies but as most are near the coast in undeveloped land, current subpopulations of Cape Spider-orchid are not threatened by land clearing (WA DEC 2007).

Research has indicated that adult plants are most vulnerable to fire during the vegetative/flowering stage (April to early October), when replacing their parent tuber(s). If control burns are considered for the area it is strongly recommended that they should not take place between April and early October, but rather in late October and November. Where feasible, the subspecies should be protected from frequent uncontrolled fires by the construction of fire breaks or by fuel reduction in surrounding areas (WA DEC 2007).

Weed control is needed in or near sites that are to be preserved for conservation of Cape Spider-orchid is desirable. Populations near recreation facilities, car parks and rest areas are particularly vulnerable as weed seeds are transported to these sites by vehicles. It is recommended that weeds be controlled biannually in March or late October when the orchid is dormant. Some subpopulations are more susceptible to weed invasion than others, and subpopulations 2 and 4 have been affected by weeds. Specifically, subpopulation 4 is affected by Arum Lily and Afgan Thistle (WA DEC 2007).

Cape Spider-orchid habitat has been modified through the removal of granite rocks, presumably for their value to landscape gardeners. Grazing by kangaroos also appears to have some impact on Cape Spider-orchid subpopulations (1, 2 and 3), as many plants have been damaged. Usually only the leaves are affected and not the flowers, and not all plants in the subpopulation are damaged. Subpopulation 2 had been heavily grazed in some areas when surveyed in 2006. There has been no evidence of direct grazing of Cape Spider-orchid plants by rabbits or any other introduced herbivores. However, in view of the potential such introduced species have for degrading habitats, it is strongly recommended that populations be monitored for any possible threat from such grazing (WA DEC 2007).

Subpopulation 3a is particularly close to a track and is regarded as healthy, but the surrounding vegetation is degraded through weeds and human activity as recreational use is heavy (WA DEC 2007).

A survey of subpopulation 6 in August 2006 noted that horses had been walked along the path and that there was potential for weeds to be spread into the Cape Spider-orchid population and the associated Meelup Granite TEC (WA DEC 2007).

The subspecies is vulnerable to damage or destruction owing to the small areas occupied by its populations, and should be protected from accidental destruction by bulldozing (of access roads, firebreaks or for nature walks), rubbish dumping, and spraying of potentially damaging herbicides or insecticides (WA DEC 2007).

Subpopulation 5 and part of subpopulation 2 occur on private property and are potentially at risk in the future from development (WA DEC 2007).

Landowners have been made aware of the occurrence of this subspecies on their property. Where appropriate, road markers have been installed (WA DEC 2007).

The taxonomy was originally described by Hopper and Brown (2001b).

The conservation genetics and population ecology of the Cape Spider-orchid was studied by Carstairs and Coates (1994).

There is a draft interim recovery plan in place for the Cape Spider-orchid: Cape Spider Orchid (Caladenia caesara subsp. maritima) Interim Recovery Plan No. 232 (2007–2011) (WA DEC 2007b).

The subspecies is described in the Declared Rare and Poorly Known Flora in the Central Forest Region Wildlife Management Program No. 33 (Williams et al. 2001).

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
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Caladenia caesarea subsp. maritimain Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006cw) [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].
Human Intrusions and Disturbance:Recreational Activities:Soil disturbance and/or trampling due to bushwalking Cape Spider Orchid Caladenia caesarea subsp. maritima Recovery plan (Department of Environment and Conservation, 2010) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Oryctolagus cuniculus (Rabbit, European Rabbit) Cape Spider Orchid Caladenia caesarea subsp. maritima Recovery plan (Department of Environment and Conservation, 2010) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Cape Spider Orchid Caladenia caesarea subsp. maritima Recovery plan (Department of Environment and Conservation, 2010) [Recovery Plan].
Caladenia caesarea subsp. maritimain Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006cw) [Internet].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, predation and/or habitat degradation by kangaroos and wallabies Cape Spider Orchid Caladenia caesarea subsp. maritima Recovery plan (Department of Environment and Conservation, 2010) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Cape Spider Orchid Caladenia caesarea subsp. maritima Recovery plan (Department of Environment and Conservation, 2010) [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].
Species Stresses:Indirect Species Effects:Low numbers of individuals Caladenia caesarea subsp. maritimain Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006cw) [Internet].
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].

Brown, A., C. Thomson-Dans & N. Marchant, eds. (1998). Western Australia's Threatened Flora. Como, Western Australia: Department of Conservation and Land Management.

Carstairs, S. & D. Coates (1994). Conservation Genetics and Population Ecology of Five Rare and Threatened Western Australian Orchids. Endangered Species Unit, Australian Nature Conservation Agency.

Department of Environment and Conservation (2010). Cape Spider Orchid Caladenia caesarea subsp. maritima Recovery plan. [Online]. Kensington, Western Australia: DEC. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/caladenia-caesarea.html.

Hoffman, N. & A. Brown (1992). Orchids of South-west Australia 2nd edn. Nedlands, Western Australia: University of Western Australia Press.

Hoffman, N. & A. Brown (1998). Orchids of South-west Australia Rev. 2nd edn. Nedlands, Western Australia: University of Western Australia Press.

Hopper, S.D. & A.P. Brown (2001b). Contributions to Western Australian orchidology: 2. New taxa and circumscriptions in Caladenia (Spider, Fairy and Dragon Orchids of Western Australia). Nuytsia. 14(1/2):27-314. Perth, Western Australia: Department of Conservation & Land Management.

Western Australia Department of Environment and Conservation (WA DEC) (2007). Records held in DEC's Declared Flora Database and rare flora files. Perth, Western Australia: Department of Environment and Conservation.

Western Australian Department of Environment and Conservation (WA DEC) (2007b). Cape Spider Orchid (Caladenia caesara subsp. maritima) Interim Recovery Plan No. 232 (2007-2011). Perth: Department of Environment and Conservation.

Western Australian Herbarium (n.d.). FloraBase - The Western Australian Flora. [Online]. Western Australia, Department of Conservation and Land Management. Available from: http://florabase.calm.wa.gov.au/.

Williams, K., A. Horan, S. Wood & A. Webb (2001). Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2. [Online]. Western Australian Wildlife Management Program No. 33. Department of Conservation and Land Management. Available from: http://www.dpaw.wa.gov.au/plants-and-animals/threatened-species-and-communities/threatened-plants.

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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 caesarea subsp. maritima in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 24 Jul 2014 18:06:32 +1000.