Eriocaulon carsonii

Eriocaulon carsonii Photo: DERM

Scientific name: Eriocaulon carsonii

Family: Eriocaulaceae

Conservation status: Eriocaulon carsonii is listed as Endangered in Queensland (Nature Conservation Act 1992), New South Wales (Threatened Species Conservation Act 1995), South Australia (Australian National Parks and Wildlife Act 1972) and nationally (Environment Protection and Biodiversity Conservation Act 1999). It is ranked as a high priority under the Department of Environment and Resource Management Back on Track species prioritisation framework.

Description

E. carsonii is a perennial herb (i.e. it reproduces more than once and lives for more than one year) that has a circular cluster of leaves at its base and clustered flowers that form a tight head. The plant usually forms mat-like colonies and varies in appearance. For example, smaller plants (up to 10 cm tall) with hairless flower heads are found in western Queensland, while larger plants (up to 50 cm tall) with hairy flower heads occur in southern, eastern and northern Queensland. Distinct sub-species have recently been recognised (Davis et al. 2007).

Habitat and distribution

E.carsonii is only known from spring wetlands fed by permanent groundwater in relatively flat landscapes except for one population which is found in a spring-fed area on the side of a gentle range. In Queensland E. carsonii is known from 12 spring complexes. A spring complex is a group of springs where neighbouring pairs of springs are not more than six kilometres apart and all occur on similar landforms (Fensham & Fairfax 2003). With the exception of two populations in the Einasleigh Uplands region of north Queensland, the Great Artesian Basin sustains the wetlands which support this species. E. carsonii is also recorded from one spring complex in New South Wales and nine in South Australia.

Spring wetlands in the Great Artesian Basin have been well surveyed and there is a high level of certainty that no further complexes containing E. carsonii will be found. Two populations are known to have become extinct as a consequence of Great Artesian Basin springs becoming inactive, one of these is in southern Queensland and is in the largest spring of the Eulo region (Wiggera Springs) (Fensham & Fairfax 2003).

Life history

E. carsonii can establish in suitable habitat within areas where it is known to occur, and is also capable of spreading over large distances. Reproduction is based on the production of abundant tiny seeds that germinate readily. This species is also capable of growth and spread through suckering which forms dense mats.

Threatening processes

Threats to E. carsonii and other native species dependent on natural discharge of groundwater from the Great Artesian Basin include:

The artificial removal of groundwater which reduces spring flows into wetlands can leave many spring complexes completely inactive.
Damage to spring wetlands through excavation.
The introduction of exotic species such as para grass and hymenachne in ponded pastures can compete with and may exclude native plant species from their habitat.
Trampling by grazing animals around the edges of spring wetlands which disturbs vegetation and native species populations.
The removal and destruction of vegetation by pig rooting (extensive digging to find food such as tubers, worms and soil invertebrates).

What can you do to help this species

Avoid excavating spring wetlands containing E. carsonii.
Do not plant exotic ponded pasture species or other exotic weed species in spring wetlands.
Fence spring wetlands to control stock-use and exclude feral pigs.
Do not construct dams that would result in the flooding of springs.
Avoid developing new bores for groundwater use or using existing bores that will negatively affect native species populations.

Further information

Fensham RJ, Ponder, WF and Fairfax, RJ 2010. Recovery plan for the community of native species dependent on natural discharge of groundwater from the Great Artesian Basin. Report to the Department of Environment, Water, Heritage and the Arts, Canberra. Queensland Department of Environment and Resource Management, Brisbane.

References

Davies, RJ, Craigie, AI, Mackay, DA, Whalen, MA, Cheong, JP, & Leach, GL 2007. Resolution of the taxonomy of Eriocaulon (Eriocaulaceae) taxa endemic to Australian mound springs, using morphometrics and AFLP markers. Australian Systematic Botany, 20(5), 428-447.

Fensham, RJ & Fairfax RJ 2003. Spring wetlands of the Great Artesian Basin, Queensland, Australia. Wetland Ecology and Management. 11:343-362.

Last updated 8 July 2011