Indicative distribution
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.
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The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Amphibromus fluitans
Profile last updated:
15 Aug 2018
Description
A perennial grass to 0.8 m tall that spreads by both underground and above-ground stems. Flowering stems tend to be somewhat sprawling, except for the flowering portion of the stalk, which is erect and up to 35 mm long. The leaf blade is 2 - 4.5 mm wide, rough to touch and deeply ribbed. The structure that breaks away from the flower-stalk (and contains the seed) is two-toothed, with a straight bristle arising about half way up its back. The species is virtually aquatic, often with only the flower heads above the water.
Distribution
There are many historic collections in the City of Greater Albury. It has been recorded recently in lagoons beside the Murray River near Cooks Lagoon (Shire of Greater Hume), Mungabarina Reserve, East Albury, at Ettamogah, Thurgoona (Charles Sturt University Campus), near Narranderra, and also further west along the Murray River (near Mathoura) and in Victoria. There is a recent record of this species near Laggan in Upper Lachlan Shire. It is also found in Victoria and in Tasmania.
Habitat and ecology
- Amphibromus fluitans grows mostly in permanent swamps. The species needs wetlands which are at least moderately fertile and which have some bare ground, conditions which are produced by seasonally-fluctuating water levels.
- Habitats in south-western NSW include swamp margins in mud, dam and tank beds in hard clay and in semi-dry mud of lagoons with Potamogeton and Chamaeraphis species.
- Flowering time is from spring to autumn or November to March.
- Amphibromus fluitans appears to fruit later than the other grasses with which it grows. The flower heads remain almost hidden by the leaf sheaths until the seeds are nearly mature, and even then elongation of the stems is barely sufficient to expose the heads completely.
- Disturbance regimes are not known, although the species requires periodic flooding of its habitat to maintain wet conditions.
- Has been observed covering several hectares in area. The species is also recorded as occasional to common in populations.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Pastoral development. Many suitable habitats are grazed and trampled by stock. All species of Amphibromus are generally very palatable to stock.
- Changing water regimes, such as the directing of water from nearby farmlands into the wetland habitats of Amphibromus fluitans, has resulted in a reduction in the period in which the shores are exposed and a raising of the fertility of the water, producing in turn more vigorous growth of competitive adventive grasses.
- Invasion of remnant habitats by exotic grasses and weeds.
- Human-induced disturbance to natural flow regimes including the altered natural flows of the river systems as a result of river regulation, the draining and conversion of natural wetlands to deeper, permanent dams, and the alteration of natural flows across the floodplains through the development of infrastructure including roads, channels and levee banks.
- Grazing and trampling by livestock and horses, particularly when the swamps dry out and the species become accessible
- Invasion of remnant habitats by exotic grasses and weeds
Recovery strategies
A Saving Our Species conservation project is currently being developed for this species and will be available soon. For information on how you can contribute to this species' recovery, see the Activities to assist this species section below.
Activities to assist this species
- Retain or reintroduce ecologically sustainable water flows to wetland habitat.
- Erect signs beside roadside populations to alert road maintenance staff to the presence of populations.
- Fence off habitat areas to protect from stock.
Information sources
- Hogbin, P. (2002) Review of the Threatened Species Conservation Act Flora Schedules: Recommendations to the Scientific Committee.
- Jacobs, S.W.L. and Hastings, S.M. (1993) Amphibromus. Pp. 596-7 in Harden, G.J. (ed.) Flora of New South Wales. Volume 4 (New South Wales University Press, Sydney).
- Jacobs, S.W.L. and Lapinpuro, L. (1986) The Australian species of Amphibromus (Poaceae). Telopea 2(6): 715-729
- Kirk, T. (1884) Notice of the discovery of Amphibromus in New Zealand, with description of a new species. Transactions and Proceedings of the New Zealand Institute 16: 374-375
- Morris, P.F. (1934) Some notes on the grass genus Amphibromus. The Victorian Naturalist 51(6): 144-147
- Murray Catchment Management Authority and Office of Environment and Heritage (2012) New South Wales Murray Biodiversity Management Plan: A guide to terrestrial biodiversity investment priorities in the central and eastern NSW Murray catchment. (Murray CMA, Albury)
- Ogle, C. (1987) A rarely seen native grass, Amphibromus fluitans. Wellington Botanical Society Bulletin 43: 29-32.
- Porteners, M. and Robertson, G. (2003) Threatened Plants in Western New South Wales: Information Review. (NSW NPWS, Hurstville)
- Pressey, R.L., Cohn, J.S. and Porter, J.L. (1990) Vascular plants with restricted distributions in the Western Division of New South Wales. Proceedings of the Linnean Society of New South Wales 112: 213-227
- Walsh, N.G. and Entwisle, T.J. (1994) Flora of Victoria. Volume 2, Ferns and Allied Plants, Conifers and Monocotyledons. (Inkata Press, Melbourne)
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