Basalt Rustyhood

 

 

Basalt Rustyhood
Pterostylis basaltica
Kingdom:   Plantae
Phylum:   Magnoliophyta (Angiosperm)
Class:   Magnoliopsida (Monocotyledon)
Subclass   Liliidae
Order:   Orchidales
Family:   Orchidaceae
Status
Australia:    endangered (EPBC Act 1999)
Victoria:    endangered (DEPI 2014)  
FFG:    listed, Action Statement No. 137

 

The Basalt Rustyhood (also known as the Basalt Greenhood) was only described in 1993 (Jones & Clements 1993). It is regarded as being one of the most threatened orchids in Australia and is endemic to the south-west of Victoria. 

Flower stem grows to 30cm tall with 3-5 closely sheathing stem leaves. It has up to fifteen flowers 1.5cm in length, which are translucent with prominent green or greenish-brown stripes. Between 8 to 15 dull green basal rosette leaves (30mm long by 10mm wide) are closely arranged at the base of the plant, they are more pronounced during the non-flowering period and usually withered by the time of flowering.

Distribution

The Basalt Rustyhood is only known from two locations in close proximity to each other in the Dundonell area of the Victorian Volcanic Plains bioregion.

All known records of Basalt Rustyhood. Source:VBA 2015

Habitat & ecology 

The Basalt Rustyhood grows in a 500-700 mm rainfall area on 'stony rises' on the western basalt plains. It is found on shallow, sometimes bare, soil surrounded by basalt rocks occurring in native grasslands containing Kangaroo Grass Themeda triandra and Common Everlasting Chrysocephalum apiculatum.  The orchid's new growth commences in late summer to early autumn and the rosette of the orchid actively grows from May to October. Flowering takes place from November to January subject to seasonal conditions. Small flies or fungus gnats carry out pollination.

Threats

At present there are no known populations in conservation reserves which means close co-operation with private land holders and the Moyne Shire is required to ensure the long term viability of this species.

Weed invasion is considered a major threat to the Basalt Rustyhood, particularly as it grows in such a limited ecological niche, which includes sparse ground cover that can be easily occupied by weedy species. Physical disturbance to soil in and around the population has the potential to increase weed invasion.  Broad scale spraying near these populations may increase in the presence of weeds and result in loss of the population. Particular care needs to be taken with roadside works and the movement of stock in the area. Grazing by rabbits may impact on the success of flowering and development of seed. Genetic isolation and limited natural pollination may also have longer-term consequences.

Conservation of the Basalt Rustyhood

Detailed population monitoring of the site has occurred since 1996 and land managers are aware of the delicate state of the population.

Moyne Shire, volunteer groups, including Land Protection volunteers, the Australian Native Orchid Society, International Student Volunteers, Country Fire Authority and landholders have also assisted with the recovery of this species by taking part in roadside surveys, monitoring and maintenance.

Bi-annual monitoring involves collecting information on the number of plants present, number of pollinated plants, number of flowering plants and seed pod development.

Hand pollination has been use to successfully produce viable seed as natural pollination rates are very low. seed has been collected and stored in the Victorian Conservation Seed Bank at the Royal Botanic Gardens.

Hand pollination of Basalt Rustyhood is undertaken to increase the success of producing viable seed.

Specific conservation measures

Private Property site

Continue to monitor populations, collecting information on total number of plants, number of flowering plants and pollination success/seed pod development.

Protect key private land populations in cooperation with landholders, possibly through a formal area agreement.

Dundonell roadside site

Develop and implement a weed control plan for this site. This will involve a full evaluation of the weed flora on the site as well as an evaluation of all weed management options, taking into consideration the species involved, population sizes, locations, proximity to the orchids, etc.

Establish photo points at the site to provide useful information on recruitment success and orchid development. A monitoring protocol, specifically dealing with this site, the Basalt Rustyhood and other ''Pterostylis'' populations will also be prepared to ensure protection of the populations whilst undertaking monitoring.

Liaise with CFA over fire management issues.

Continue to monitor populations, collecting information on total number of plants, number of flowering plants and pollination success/seed pod development.

Undertake hand pollination.

Collect seed for propagation by Royal Botanic Gardens.

Recent outcomes

2009

2010

2011

2012

2013

2014

2015

2016

Selected references

Australian Government, Biodiversity Species Profile and Threats Database   Pterostylis basaltica Basalt Greenhood

Backhouse, G. and Jeanes, J.  (1995). The Orchids of Victoria. Melbourne University Press, Carlton, Victoria.

DEPI (2014) Advisory List of Rare Or Threatened Plants In Victoria - 2014 pdf Department of Environment, Land, Water & Planning Victoria

DSE (2003) Flora & Fauna Guarantee Action Statement No.137 Basalt Greenhood, ''Pterostylis basaltica'', Department of Sustainability & Environment, Victoria. Action Statement No.137 Basalt Greenhood pdf.

Ingeme, Y., Backhouse, G. (1999) Basalt Greenhood (Pterostylis basaltica) Recovery Plan 2000-2004 Department of Natural Resources and Environment, Melbourne.

Jones, D.L. & Clements, M.A. (1993). New Species of Pterostylis. R.Br. (Orchidaceae) from Victoria and New South Wales.  Muelleria 8 (1) 73-83.  National Herbarium of Victoria.

VBA (2015) Victorian Biodiversity Atlas, Department of Environment, Land, Water & Planning, East Melbourne, Victoria. Accessed October 2015.

Vlcek, K and Pritchard, A. (2010)  National Recovery Plan for Basalt Rustyhood Pterostylis basaltica. Department of Sustainability and Environment, East Melbourne. National Recovery Plan for Basalt Rustyhood Pterostylis basaltica 

Walsh, N.G. & Entwisle, T.J. (1994) Flora of Victoria, Volume 2 - Ferns and Allied Plants, Conifers and Monocotyledons.  Inkata Press,  Melbourne.

Basalt Rustyhood. Image: Yvonne Ingeme

Please contribute information regarding the Basalt Rustyhood - observations, images or projects. 

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