Grassy wetlands occur in depressions in the upland grassland regions in New South Wales and the Australian Capital Territory and cover approximately 1565 ha on the Monaro Plateau. Because upland wetlands are not connected to rivers or streams, the duration of water inundation depends on their catchment area, rainfall patterns and the degree of past and current disturbance, but it ranges from near permanent (rarely dry), through intermittent (seasonally dry) to ephemeral (occasionally full). Plant species diversity tends to be highest in the seasonally dry wetlands, because water levels protect them from grazing but are not so high as to exclude most species. Most of the wetlands are small (less than 10 ha) and situated in agricultural landscapes, which makes them vulnerable to threats such as damming, draining, grazing, trampling and fertiliser pollution.
The Upland Wetlands of the Monaro Plateau are dominated by sedges such as Eleocharis acuta (Common Spike-rush), E. pusilla (Small Spike-rush), E. sphacelata (Kaya), Carex gaudichaudiana and C. bichenoviana, or by grasses such as Lachnagrostis filiformis (Blown Grass), Amphibromus nervosus (Common Swamp Wallaby-grass) or Glyceria australis (Australian Sweet-grass). The extent of these species is determined by water depth; deeper wetlands tend to have vegetation only on their shores and shallow reaches, but shallow wetlands have vegetation across the depression and may appear as grassland during dry periods. Commonly associated aquatic species include Potamogeton tricarinatus (Floating Pondweed), Myriophyllum variifolium (Varied Water-milfoil), Nymphoides geminata (Entire Marshwort), Stellaria angustifolia (Swamp Startwort), Lobelia surrepens, Hydrocotyle tripartita (Pennywort), Epilobium billardiereanum subsp. cinereum (Variable Willow-herb), Brachyscome radicans (Marsh Daisy), Crassula helmsii (Swamp Crassula), Limosella australis (Austral Mudwort), Ranunculus diminutus (Brackish Plains Buttercup) and Persicaria prostrata (Creeping Knotweed).
Amphibromus nervosus, Carex bichenoviana, Carex gaudichaudiana, Centipeda cunninghamii, Crassula helmsii, Eleocharis acuta, Eleocharis pusilla, Eleocharis sphacelata, Glossostigma elatinoides, Hydrocotyle peduncularis, Isolepis platycarpa, Lachnagrostis filiformis, Lepilaena bilocularis, Limosella australis, Myriophyllum caput-medusae, Myriophyllum simulans, Myriophyllum verrucosum, Montia australasica, Nymphoides montana, Ottelia ovalifolia, Persicaria prostata, Potamogeton tricarinatus, Pratia surrepens, Ranunculus diminutus, Schoenoplectus pungens, Stellaria angustifolia