Sand-hill Spider Orchid - profile

Indicative distribution

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Key:

known

predicted

The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.

Scientific name: Caladenia arenaria

Conservation status in NSW: Endangered

Commonwealth status: Endangered

Gazetted date: 18 Jul 1997

Profile last updated: 07 Jun 2022

Description

Sand-hill Spider Orchid is from a group of orchids characterised by five long, spreading petals and sepals around a broad down-curled labellum (‘lip’). Its densely hairy leaves are reddish at the base, up to 10 cm long and 6 mm wide. The flower stalk is up to 40 cm tall and has 1 or 2 pale yellow flowers. The petals and lateral sepals are stiffly spread into a cross shape; the tips of all are red and hairy. The labellum is only 8 mm across when flattened out and without lobes; this combination of flower characters is unique. The flowers appear between September and November.

Distribution

Caladenia arenaria is found mostly on the south west plains and western south west slopes. The original description is of a plant from Nangus, west of Gundagai (1865) and there is a report of the species from Adelong near Tumut. A record near Cootamundra needs verifying. The Sand-hill Spider Orchid is currently only known to occur in the Riverina between Urana and Narranderra.

Habitat and ecology

Occurs in woodland with sandy soil, especially that dominated by White Cypress Pine (Callitris glaucophylla).

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.

Threats

At risk from stochastic events because of the low number of plants.
Sensitive to browsing by feral herbivores.
Sensitive to grazing and ground disturbance by domestic stock.
Competition from native species.
Forestry operations such as thinning, harvesting, roads, and track construction impact the species.
Unsure about the impacts of Callitris thinning and fire on the species.
Possibly sensitive to browsing by native herbivores.
Hybridisation occurring at some populations reducing genetic viability of species.

Recovery strategies

A targeted strategy for managing this species has been developed under the Saving Our Species program; click here for details. For more information on the Saving Our Species program click here

Activities to assist this species

Weed control should be performed as required.
Forests NSW and OEH implement appropriate strategies for the protection and recovery of this species in State Forests. Negotiations be undertaken with the owner of the population on private property to enter some form of conservation agreement.
Monitor all populations each year to determine trends in mortality and recruitment.
Pollination and seed-set is monitored for each of the populations.
Establish exclosures to examine the influence of vertebrate herbivores.
The germination requirements of the species are researched and an ex-situ strategy developed. Re-introduction could be considered in appropriate habitat.

Information sources

Bernhardt, P. (1993) Caladenia. Pp 196-209 in Harden, G.J. (ed.) Flora of New South Wales. Volume 4. (New South Wales University Press, Sydney)
Bishop, T. (2000) Field Guide to the Orchids of New South Wales and Victoria. (New South Wales University Press, Sydney)
Department of Environment and Conservation (NSW) (2004) Caladenia arenaria Fitzg.Recovery Plan. (NSW DEC, Sydney)
Murray Catchment Management Authority and Office of Environment and Heritage (2012) New South Wales Murray Biodiversity Management Plan: A guide to terrestrial biodiversity investment priorities in the central and eastern NSW Murray catchment. (Murray CMA, Albury)
NSW Scientific Committee (1997) Caladenia arenaria (a terrestrial orchid) - Endangered species determination - final.
Porteners, M. and Robertson, G. (2003) Threatened Plants in Western New South Wales: Information Review. (NSW NPWS, Hurstville)

IBRA Bioregion	IBRA Subregion	Known or predicted	Geographic restrictions region

NSW South Western Slopes	Inland Slopes	Known	None
NSW South Western Slopes	Lower Slopes	Known	West of Lockhart and north of Rand
Other State	SA	Known	None
Riverina	Murrumbidgee	Known	East of Jerilderie