Family: - Asphodelaceae.Names:
Summary:Dune Onion Weed has clumps of drooping, flattened, somewhat succulent, strap-like leaves, 350-450 mm long, emerging from underground rhizomes. The many and widely branched, stout, somewhat sprawling flowering stems carry white, 6 'petal' flowers. The “petals” are 4-14 mm long with a brownish or purplish central stripe and have two yellowish spots near their base. It has 6 stamens with yellowish anthers and a slender unbranched style. It has little or no odour.
Leaves:Several, arising from the base. Enclosed at the base by brown-purple membranous scales. No aroma.
Flower head:Many flowers, each in the axil of a bract, along the branches on erect, 5-10 mm long stalks(pedicels). Pedicels jointed just below the flower.
Flowers:Ovary - 12-20 ovules per cell. Thread like style. Stigma small, smooth edged.
Seeds:Brown or grey, angled.
Roots:Slightly thickened at the base and tapering. Fibrous. Rhizomatous.
Key Characters:Leaves and scapes enclosed at the base by brown or purplish membranous tubular scales.
Flowering times:September and October in Perth.
Seed Biology and Germination:Vegetative Propagules:
Soil:Most abundant on sandy limestone soils.
Plant Associations:Inter dune beach heath land.
Origin and History:South Africa.
Distribution:NSW, SA, WA.
Significance:It is rapidly spreading along the coast in WA.
Detrimental:Weed of pasture, bush land, coastal heath, roadsides, islands and disturbed areas
Toxicity:Relatively unpalatable and generally causes few problems where adequate feed is available. It is toxic when grazed. It appears to be toxic to most stock and most cases are recorded in horses.
Symptoms:Stiff, stumbling, uncoordinated gait, tremors and sweating leading to partial paralysis. Muscular ability but not sensation are affected. Animals tend to collapse on their sternum and death from dehydration, starvation or complications of paralysis follows. It may take 1-3 months for the symptoms to progress.
Treatment:If detected early and stock are removed from the infestation then partial or full recovery follows. In most cases it is detected too late and the disease runs its course.
Management and Control:Blanket wipers applying glyphosate and metsulfuron have given good selective control in pastures.
Herbicide resistance:None reported.
Biological Control:Related plants:
Plants of similar appearance:Onion Weed (Asphodelus fistulosus) is similar and grows in similar locations. It is distinguished by its hollow cylindrical leaves.
References:Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P22-23. Diagrams.
Acknowledgments:Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.