Corybas Dentatus Finniss Helmet-Orchid

PLANT Corybas dentatus Finniss Helmet-orchid

AUS SA AMLR Endemism Life History thought to be extinct but a few plants were rediscovered in 2007 (J. Quarmby pers. comm. 2009). V E E AMLR Perennial Recent surveys in Scott CP found plants that appeared Family ORCHIDACEAE to be hybrids between C. dentatus and C. incurvis (J. Quarmby pers. comm. 2009). Possible new populations were found in the southeast by the Native Orchid Society of South Australia (J. Quarmby pers. comm. 2009).

Post-1983 AMLR filtered records scattered from Lyndoch, Rowland Flat, Gumeracha, and Scott CP near Currency Creek.5

There are no pre-1983 records.5

Habitat Occurs in damp, grey, sandy soils under Callistemon sp. or under bracken in woodland of Eucalyptus baxteri and native pines (Jones 1991b).2

Recorded AMLR habitats include: Photo: © Cathy Houston  Scott CP: on sand under bracken

 Cockatoo Valley area: under native pines and Conservation Significance Callistemon sp. in damp soil in grazed area.6 Endemic to the AMLR where the species’ relative area of occupancy is classified as ‘Extremely Within the AMLR the preferred broad vegetation group Restricted’. Relative to all AMLR extant species, the is Heathy Open Forest.5 species' taxonomic uniqueness is classified as ‘High’.5

Within the AMLR the species’ degree of habitat C. dentatus at least in some forms may be of hybrid specialisation is classified as ‘High’.5 origin, perhaps C. incurvus crossed with a flared labellum form of C. despectans.2 Biology and Ecology

Flowers from July to August.2 Description

Terrestrial herb forming colonies (Jones 1991b).3 Leaf Aboriginal Significance to 4 cm across, green ground hugging. Flower Post-1983 records indicate the AMLR distribution occurs solitary, erect or decumbent, on short peduncle, 2-3 in southern Ngadjuri, central Peramangk and central cm across, purplish and green.2 Ngarrindjeri Nations.5

Synonym: Corysanthes dentata.7 Species of Orchidaceae are recorded as a traditional

food source for Aboriginal people in NSW. The tubers Distribution and Population were roasted (Flood 1980).1 In the AMLR occurs from Lyndoch southwards. May also occur in the Southern Flinders Ranges near Threats Wirrabara.2 Threats include:

 inappropriate use of herbicides (e.g. at Sandy Exact distribution uncertain due to possible confusion Creek CP for Bridal Creeper control)2 with C. incurvus and possible hybridisation (Jones  roadwork 1991b). In SA restricted to 250 – 450 m altitude.7  human impacts related to nearby residential

development4 Thought to occur in two populations, Sandy Creek  small population size and Scott CP. The Sandy Creek population was

Further information: Biodiversity Conservation Unit, Adelaide Region Phone: (61 8) 8336 0901 Fax: (61 8) 8336 0999 http://www.environment.sa.gov.au/  Department for Environment and Heritage FIS 90346 May 2008 Prepared as part of the Regional Recovery Plan for Threatened Species and Ecological Communities of Adelaide and the Mount Lofty Ranges, South Australia 2009 - 2014

 climate change. Environment and Heritage. DEWR Species Profiles and Threats Database, Canberra. Grazing by rabbits, kangaroos and livestock stock is probably not an important issue due to the plant’s 4 Department for Environment and Heritage. (2007). Adelaide and Mount Lofty Ranges Regional Recovery Pilot Expert Flora small size (R. Bates pers. comm.). Workshop, Unpublished Notes. Participants: Bickerton, D., Croft, T., Jury, T., Lang, P., Prescott, A., Quarmby, J. and Smith, Limited distribution within the AMLR region, however K., Adelaide. approximately half its known distribution occurs within 2 km of confirmed or suspected Phytophthora 5 Department for Environment and Heritage (2007). Adelaide infestations.5 and Mount Lofty Ranges Regional Recovery Pilot Project Database. Unpublished data extracted and edited from Additional current direct threats have been identified BDBSA, SA Herbarium (July 2007) and other sources. and rated for this species. Refer to the main plan 6 Department for Environment and Heritage (2007). State accompanying these profiles. Herbarium of South Australia Database. Unpublished data, extracted October 2007. Regional Distribution 7 Jones, D. L. (2006). A complete guide to native orchids of Australia including the island territories. New Holland Publishers, Australia.

Map based on filtered post-1983 records.5 Note, this map does not necessarily represent the actual species’ distribution within the AMLR.

References Note: In some cases original reference sources are not included in this list, however they can be obtained from the reference from which the information has been sourced (the reference cited in superscript).

1 Australian National Botanic Gardens (2007). Aboriginal Plant Use - NSW Southern Tablelands. Available from http://www.anbg.gov.au/apu/index.html (accessed August 2007).

2 Bates, R. J., ed. (2007). South Australian Native Orchids. Electronic version, August 2007. Native Orchid Society of South Australia.

3 Department for Environment and Heritage (2005). Draft Species Information Sheet for Corysanthes dentata. Draft report for Australian Government Department of