Declared Rare and Poorly Known Flora in the Geraldton District

On the north-west side of the Yalgoo Sub-region, the Carnarvon Botanical District extends south into the GeraldtonDistrict as the southern part of the Toolonga Plateau. This is a flat sandplain bisected in the District by the MurchisonRiver. The red sands support Bowgada shrubland with scattered pines and eucalypts.The Southwestern Botanical Province occupies the western side of the District. Its higher winter rainfall supports morevaried plant communities than the Eremaean Province. To the north of Kalbarri along the coast, the Zuytdorp systemsupports wattle scrub and heath on the slopes of the high limestone cliffs facing the sea. Coastal heath or Melaleucathicket grows on hills, and on deeper soils, thicket of Acacia rostellifera, sometimes with patches of scrub heath. To theeast of this, north of the Murchison River, the Eurardy System has undulating sandplains with belts of yellow sandridges on the western side and red flatter sand to the east. Scrub heath with Actinostrobus arenarius, Banksia sceptrumand Xylomelum angustifolium grow on the sand ridges. Mixed scrub heath grows on the sandplain. The red sandplainto the east has Acacia-Allocasuarina thicket. On this side of the System, the North West Coastal Highway runs throughan area of mallee with thicket towards the northern boundary of the District.Along the Murchison River, the gorges and valleys are cut into the Tumblagooda Sandstone. Acacia acuminata andJacksonia cupulifera scrub occurs on the rocky areas, with Eucalyptus camaldulensis and Casuarina obesa along theriver.Along the coast south of Kalbarri, the Greenough System is associated with coastal limestone south to Dongara. Thelimestone belt varies in width and there are alluvial flats and lagoons. There are thickets of Acacia rostellifera andMelaleuca cardiophylla on rocky ridges, Acacia-Banksia scrub on sand over limestone and low forest of A. rostelliferaon alluvial flats.Much of the Kalbarri System lies within the Kalbarri National Park. It is a gently undulating sandplain of deep yellowsand and bleached sand over laterite, supporting scrub heath. Outcropping Windalia radiolarite forms low rocky hillswith Acacia-Melaleuca thicket and the heavier soils support mallees. East of this, the less resistant rocks of the AjanaSystem have allowed more extensive erosion by the Murchison River to produce shallow rocky soil. This supportsAcacia acuminata scrub with scattered York gum.The northern part of the Yuna System lies to the east of this, running south almost to the southern boundary of theDistrict. Mainly an undulating sandplain, the sand on the western side is yellow and loose, supporting scrub heath, andto the east with lower rainfall becoming red and more earthy, with Acacia-Allocasuarina thicket. The change in soiltype is patchy, producing a vegetation mosaic. On deep soils east of Yuna, there is York gum woodland, and this ispresent with salmon gum to the west of Mullewa. Where the Greenough River crosses the system, there is Acaciaacuminata scrub with scattered York gum in its valley.The Hutt System is made up of the lower drainage basin of the Hutt River, south of the Kalbarri System. Drainagechannels have cut into the plateau, exposing Tumblagooda Sandstone with thicket and scrub heath and Kockatea Shalewith Melaleuca-Hakea thicket. The remaining sandplain supports scrub heath. Eucalyptus camaldulensis, Casuarinaobesa and Melaleuca rhaphiophylla grow along the Hutt River.To the east of the Greenough System and south of the Hutt System lies the Northampton System. Here much of theplateau surface has been removed, with the remnants forming the flat-topped mesas of the Moresby Range andundulating country between. Scrub heath occurs on the mesa tops, Melaleuca-Hakea thicket on the steep scarp slopesand Acacia acuminata scrub on the lower country, with Hakea and scattered Eucalyptus loxophleba. E. camaldulensisis scattered in drainage lines.On coastal limestone around Dongara lies the northernmost section of the Ilyarrie System, which takes its name fromEucalyptus erythrocorys, which characteristically grows in small groves on exposed limestone. To the east of this liesthe northern part of the Tathra System. Low heath covers the laterite of ridges and breakaways. Scrub heath with smallpatches of Melaleuca thicket and woodland cover the sandplain between the ridges.The south-eastern section of the South Western Botanical Province in the District lies to the south-east of the YunaSystem. The Mullewa System has sandplains similar to those further west, with Acacia-Allocasuarina-Melaleucathickets. The residual sandplain of the Pindar System, around the headwaters of the Irwin, has been stripped on muchof the high ground, the shallow red loams over granite supporting Acacia ramulosa shrubland on hills, A. acuminatathicket on red sand and eucalypt woodland on red loam in the valleys.20