The naturalized vascular plants of Western Australia 1: Checklist, environmental weeds and distribution in IBRA regions

Greg Keighery and Vanda Longman, Department of Conservation and Land Management, WA Wildlife Research Centre, PO Box 51, Wanneroo, Western Australia 6946, Australia.


There are 1233 naturalized vascular plant taxa recorded for Western Australia, composed of 12 Ferns, 15 Gymnosperms, 345 Monocotyledons and 861 Dicotyledons. Of these, 677 taxa (55%) are environmental weeds, recorded from natural bushland areas. Another 94 taxa are listed as semi-naturalized garden escapes. Most are herbaceous annuals or grasses with the largest groups being the Poaceae (196), Asteraceae (115), Papilionaceae (106) and Iridaceae (53).

The largest numbers of weeds are recorded from the natural regions encompassing the capital Perth, with 801 and 705 recorded for the Swan Coastal Plain and Jarrah Forest Bioregions respectively.

Most weeds are still localized in extent with only 60 occurring in 10 or more natural regions, the vast majority in less than three, suggesting that further spread will occur in most weeds.


Plant Protection Quarterly (2004) 19 (1) 12-32.