Endangered plants
Lamington eyebright. Euphrasia bella.
Photo: Wayne AbbotAbout 13 percent of Queensland’s native plant species are rare or threatened.
23 species are Extinct in the wild, 151 species are Endangered, 274 species are Vulnerable and 688 species are rare. These plants are in danger of extinction in the next 10–50 years unless action is taken to reverse their decline.
Triunia robusta, a small rainforest tree related to the macadamia nut tree, was presumed extinct until re-collected near Nambour in 1989. This tree has since been found in two other small rainforest remnants on the Sunshine Coast but is still considered endangered.
The exquisite moth orchid found in wet tropical rainforests and Tectaria devexa, a fern found only Rockhampton, are endangered.
Queensland's floral emblem, the Cooktown orchid, Keys’ boronia which grows in the coastal lowlands east of Gympie, and ooline, a relict rainforest tree growing in dry vine thicket in southwestern and central Queensland, are considered vulnerable.
Calamus aruensis, a climbing palm found in Australia only in monsoon rainforest pockets in far north Cape York Peninsula, is listed as rare.
All plants are Common unless otherwise indicated. Silver-leafed ironbark Eucalyptus melanophloia is very widespread and more likely to survive than plants which are under threat or very restricted in habitat.
Lists of rare and threatened plants are included in the Nature Conservation (Wildlife) Regulation 1994 under the Nature Conservation Act 1992.
What causes species to decline?
Loss of natural habitat through land clearing for pastoral purposes, urban development and agriculture is the main reason. Grazing pressure from domestic stock and introduced animals (such as rabbits), changing fire patterns and the spread of weeds are others.
The long-term effects of fire, weeds, and pests on plants are poorly understood.
Changes in the frequency and intensity of fire can cause plant populations to decline. Some species such as south-east Queensland’s Keys’ boronia Boronia keysii depend on a suitable fire regime for successful regeneration and survival.
Collecting native plants and plant parts for the nursery, floral and bush tucker trade is another threat to some of our native plants.
Apart from vegetation clearing, plant collecting is the greatest threat to attractive rare and threatened species such as orchids and ferns. Under the Nature Conservation Act 1992 and Nature Conservation (Wildlife) Regulation 1994, the harvesting and sale of native plants and plant parts are closely regulated.
What happens?
Although extinction can take a long time, the process is not always obvious until the situation is critical. Take the case of the Christmas bell Blandfordia grandiflora.
Christmas bells once flourished in south-east Queensland’s swampy coastal lowlands between the New South Wales border and Fraser Island. The flowers appeared during summer and the plants flowered most profusely up to two years after fire.
The spectacular show of the yellow (or yellow and red) flowers attracted the attention of florists, particularly around Christmas time, and the flowers were commonly sold at roadside stalls.
Today, many people have never seen a Christmas bell. Many coastal swamps have been cleared and drained for pine plantations and for housing. Christmas bells are now rarely found outside reserves such as national parks and state forests.
The Christmas bell is now classed as rare — its population has declined markedly. Loss of habitat, excessive harvesting, changed bushfire frequency and weed infestation have been the major causes of its decline. The Christmas bell is a protected plant.
How can plants be conserved?
The Environmental Protection Agency has a research and monitoring program for Queensland’s rare and threatened plants. Once the extent of a plant species’ distribution and population numbers are determined, a recovery plan can be developed to ensure the plant’s survival.
The first step is to conserve significant habitat areas. The reasons for rarity or scarcity must then be identified and controlled or eliminated. Key plant populations must be protected. This can require fencing, de-stocking, ongoing research, propagation and reintroduction.
Protecting only one population is not a viable option as it could be destroyed by a catastrophe such as a cyclone or fire. Protecting several populations of a species is essential. Without genetic variation, a species becomes weak and more susceptible to disease and other threats.
Protected areas
Habitat protection is critical for plant survival. Only half the state’s rare and threatened plant species occur in protected areas which cover about four percent of the state.
National parks alone will not guarantee the long-term survival of our native plants. Other protection measures are needed.
The presence of rare or threatened plants is one criteria used to decide whether a particular area should become a protected area.
Under the Nature Conservation Act 1992, private landholders can enter into agreements which will protect rare and threatened plants on their properties.
Controls on the plant trade
Collecting rare and popular native plants and selling them is a profitable business.
Some ferns, tree ferns, cycads and orchids are seriously threatened by collecting for the nursery and floral trade and private gardens. Overcollecting even threatens common plants like grasstrees and staghorns.
Individual plants can be damaged when stems, fruits and flowers are removed for florist use. Whole plants are often removed from the wild for planting in home gardens or sale in nurseries. Collecting a plant’s seeds reduces the prospects for successful regeneration.
Collecting protected native plants and plant parts from the bush and selling native plants is controlled through a licensing system. Restrictions apply to sought-after native plants and some rare and threatened plants.
All rare and threatened plant species and some common species offered for sale must be tagged by the collector or propagator.
These controls should ensure that plant species survive in the bush, not just in national parks and botanic gardens.
Conservation through cultivation
Botanic gardens and plant nurseries may have a role in conserving rare and threatened plants by propagating and cultivating species to lessen the demand for wild-collected plants.
Botanic gardens in Brisbane, Townsville, Atherton and Cairns grow rare and threatened species. Members of the Society for Growing Australian Plants also keeps many native plants in cultivation.
The Queensland Parks and Wildlife Service operates a plant nursery at Lake Eacham on the Atherton Tableland. Here, more than 50 rare and threatened plant species and many common species suitable for rehabilitation projects are cultivated.
Case studies
Cadellia pentasylis (ooline) Vulnerable
This medium to large small-leaved tree is found in inland southern and central Queensland and New South Wales.
A relict of the Gondwanan rainforests which once covered inland Australia millions of years ago, ooline is an example of a tree once relatively common but now threatened as a result of human activities.
Clearing for agriculture, grazing as well as fire are the main reason’s for ooline’s decline.
One very small stand remains in Sundown National Park and other populations survive in Tregole National Park and the Moolyamber Section of Carnarvon National Park.
The remainder are on private lands. Landholder co-operation is needed to protect these remaining colonies.
Tectaria devexa Endangered
This fern is known in Australia from a single site north of Rockhampton. Here, it grows on walls, crevices, ledges and large rocks.
Because it is so restricted, this fern is susceptible to local extinction as a result of gradual loss of vigour or a single catastrophe.
Graptophyllum reticulatum Endangered
This small shrub grows in remnant rainforest in the Sunshine Coast. This plant is not known to occur on any protected area in Australia. Whether it can be successfully propagated is also unknown.
Diploglottis campbellii (small-leaved tamarind) Endangered
This large straight rainforest tree with dense cream flowers and yellow-brown fruit is found only in the coastal lowlands of extreme south-east Queensland and northern New South Wales.
Because this tree’s habitat has been cleared for agriculture and urban development, only five mature trees are known to remain in Queensland. All known trees grow outside protected areas but it can be propagated.
Triunia robusta Endangered
This straggly, multi-stemmed small tree has white flowers and red fruit.
Previously believed to be extinct, this species has since been located in subtropical rainforest in Noosa Shire. It also grows in Triunia National Park (Scientific) on the Blackall Range. This tree has not been propagated successfully.
Acronychia littoralis (scented acronychia) Endangered
This is a small tree with lush creamy-yellow flowers. Scented acronychia is known from two trees at a single site on the Gold Coast and from trees in and near the Cooloola Section of Great Sandy National Park.
Cultivation and re-introduction into its former habitat might be the only way to guarantee this plant’s survival.
Acacia peuce (waddy) Vulnerable
Known from only three locations in Australia, waddywood’s foliage resembles pine needles.
The largest remaining stand is in the channel country near Boulia in far western Queensland.
Forming pure stands of open woodland or found as single trees, waddy is possibly a relict of previous wetter times and was stranded when the Simpson Desert formed.
The main threats to its survival are drought, fire and grazing pressure from rabbits and stock.
Eucalyptus hallii (Goodwood gum) Vulnerable
This tall-growing gum grows only in the coastal lowlands between Bundaberg and Howard.
Much of its habitat has been cleared for agriculture and urban development.
Small populations are protected in Burrum Coast National Park but further habitat reservation is essential to guarantee its survival.
The future
Protected areas such as national parks play an important role in conserving plants.
Controls on harvesting and selling native plants should ensure that future activities are ecologically sustainable and do not threaten the survival of attractive native plants.
You can help by getting your garden native plants from nurseries not from natural bushland.
With continuing research, effective management and the community’s help, no further endangered plant species should become extinct and the future of rare and threatened plants should be secure.
Last updated: 20 June 2007
