Dune Onion Weed
Common name
Dune Onion Weed
Scientific Name
Trachyandra divaricata
Type of plant
Bulbs or Corms
About this weed
This perennial herb is a native of South Africa and is now widespread on the Swan Coastal Plain especially in coastal heathland in white and grey sand. It is similar to Onion Weed Asphodelus fistulosus in appearance but has flat leaves and the flowering stalks is widely branched.
Description
A rhizomatous, perennial herb growing to 0.35 m high. The plant produces tall flowering stalks with small white flowers in spring. Wind dislodges and carries crowns of mature inflorescences acting as tumbleweeds, spreading numerous small seeds.
Impact on Bushland
A major weed of coastal dunes and is spreading inland. Fleshy leaves are able to spread over the sand surface and may be up to 1 m long,making older plants competitive for space. Has variable fruit set, affected by the age of plants and weather conditions. Has adaptions for dispersal by wind and water. Wind dislodges and carries crowns of mature infloresences acting as a tumbleweed, spreading numerous small seeds. Germination is inhibited by light, a response to blowing sand habitats where germination on the dry surface could prove detrimental. Poisonous to mammals.
Location
Usually found on white or grey sand on coastal dunes of the Swan Coastal Plain.
Priority for removal
High: is a major weed of coastal dunes but is spreading inland.
Management (hand)
Manually remove isolated or small infestations prior to flowering. Wipe with 50% Glyphosate solution before flowering. Optimum time for removal – any month.
Management (herbicide)
For dense infestations in degraded areas spot spray 0.4 g chlorosulfuron plus 25 ml wetting agent in 10 L of water when plants actively growing. Read the manufacturers’ labels and material safety data sheets before using herbicides. Optimal months for herbicide treatment are July, August and September.
Flowering month/s
August, September, October, November
Flower colour/s
White
Information source
https://florabase.dpaw.wa.gov.au/browse/profile/1368
Additional information
https://florabase.dpaw.wa.gov.au/weeds/swanweeds/
Hussey, B.M.J., Keighery, G.J., Dodd, J., Lloyd, S.G. and Cousens, R.D. (2007) Western weeds. A guide to the weeds of Western Australia, Second Edition, The Weeds Society of Western Australia, Victoria Park, Western Australia.
