Jervis Bay Leek 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: Prasophyllum affine

Conservation status in NSW: Endangered

Commonwealth status: Endangered

Profile last updated: 27 Oct 2022

Description

The Jervis Bay Leek Orchid is a ground orchid which produces a single onion-like leaf that can grow to 40 cm long. Flowers are produced on a cylindrical stalk that emerges from about two thirds of the way up the hollow leaf. Up to 35 flowers are clustered in a spike arranged along the top third of each flower stalk. Each flower is about 9 mm across and flower colour varies between plants; including light green, yellow, red-brown and purple. The Kinghorne Point population is dominated by plants with the red-brown and purple coloured flowers. Most orchid experts consider references to Victorian populations of this species to be incorrect and attributable to other species.

Distribution

Jervis Bay Leek Orchid is currently known from three areas south-east of Nowra on South Coast. These are Kinghorne Point, Wowly Gully near the town of Callala Bay, and near the township of Vincentia.

Habitat and ecology

Grows on poorly drained grey clay soils that support low heathland and sedgeland communities.
The underground dormant tubers commence shooting in mid winter and leaves are known to have emerged above ground by June.
The flowering period reliably commences in the first week of November and extends for about 3 weeks.
Pollination is primarily by specialised wasp species. The primary pollinator is the male of one species and they are attracted to the orchid flowers by a scent of the flower that mimics that of the female wasp.
The fruit (small green ovoid capsules) develop rapidly following flowering and eventually split to release fine dust-like seeds. Each capsule contains thousands of seeds that are primarily wind dispersed.
By January the leaves and fruiting stems have withered and the plants then persist as underground tubers until they resprout the following winter.

Regional distribution and habitat

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

Sydney Basin

Threats

Loss and degradation of habitat and/or populations by clearing of habitat for residential and commercial developments.
Loss and degradation of habitat and/or populations due to increased public use of the areas where the species occurs.
Some sites are on private land. Although the current owners are supportive of protecting this species, future owners of the properties may not be as sympathetic to the protection of the species.
The restricted distribution and small population sizes of this species make it inherently vulnerable to localised stochastic events such as drought, disease and heavy browsing.
One of the sites near Vincentia is threatened due to potential infestation of the habitat from nearby occurrences of the invasive weeds, African Love Grass and Buffalo Grass.
Detailed monitoring by Department of Planning, Industry and Environment has shown that a significant proportion of flowering and fruiting plants are browsed by native herbivores (probably wallabies) and this is likely to adversely impact on future recruitment potential.
Annual monitoring since 2001 has shown a significant decline in the number of flowering plants at both Vincentia and Kinghorne Point. The reasons for this are not clear but may be due, at least in part, to increasing competition from associated native vegetation in the absence of fire. A trial ecological burn is desirable to determine whether occasional burning may be beneficial to the survival of this 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

Protect known populations from changes to land use.
Protection measures have been implemented for all known sites.
Monitor known populations to ensure that management is retaining populations, and to increase the knowledge of the species’ ecology.
Mark sites and potential habitat onto maps used for planning (e.g. road works, rehabilitation and recovery).
Search for new populations in potential habitat.
Undertake a trial burn to determine whether the observed decline in flowering plants over the past 15 years is, at least in part, attributable to increasing competition from associated native vegetation due to an absence of fire.

Information sources

Backhouse, G.N. and Jeanes, J.A. (1995) The Orchids of Victoria. (The Meigunyah Press, Melbourne)
Bishop, T. (2000) Field Guide to the Orchids of New South Wales and Victoria. (New South Wales University Press, Sydney)
Harden, G.J. (ed.) (1993) Flora of New South Wales Vol. 4. UNSW Press, Kensington, NSW.
NSW National Parks and Wildlife Service (2003) Draft Recovery Plan for the Jervis Bay Leek Orchid (Prasophyllum affine) - Draft Recovery Plan. NSW NPWS, Sydney.
Walsh, N.G. and Entwisle, T.J. (1994) Flora of Victoria. Volume 2, Ferns and Allied Plants, Conifers and Monocotyledons. (Inkata Press, Melbourne)

IBRA Bioregion	IBRA Subregion	Known or predicted	Geographic restrictions region

Other State	Jervis Bay Territory	Predicted	Within 5 km of coast
Sydney Basin	Jervis	Known	Within 5 km of coast

Images

Jervis Bay Leek Orchid, Geoff Robertson Image 1 of 7.
View slideshow.

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