Stinking Roger
Common name
Stinking Roger
Scientific Name
Monoculus monstrosus previously named Osteospermum calandestinum
Type of plant
Daisies & Thistles (Family Asteraceae)
About this weed
This annual herb can be easily identified by its slightly sticky branches and leaves. It grows to about 0.5 m tall and the flowers are distinctive with a yellow edge and brown centre to each petal. As the name implies, this is a smelly plant when handled.
Description
Stinking Roger is an erect annual producing yellow daisy flowers with red/brown centres. The seed germinates in late autumn and reproduction is by seed that is dispersed by wind, water and soil movement. The bract is slightly larger than the flower and encloses papery seeds.
Impact on Bushland
If left will spread over bushland and may impact on plant communities.
Location
This weed is widespread across undulating sandplains, hills and slopes, valley slopes, creekbeds and saline watercourses. It prefers red-brown loams or sandy clays, yellow-white or grey-brown sandy loam, brown clay loam, limestone and granite outcrops across the South-West Province.
Priority for removal
Medium: if established can impact native plant communities.
Management (hand)
Hand remove small populations and/or isolated plants prior to flowering. Optimum treatment should be done between June and September and occasionally in October.
Management (herbicide)
Try spot spraying with glyphosate at 0.5% before flowering. Read the manufacturers’ labels and material safety data sheets before using herbicides. Optimum treatment should be done between July and September and occasionally in June and October.
Flowering month/s
October, November, December
Flower colour/s
Red, Yellow, Brown
Information source
https://florabase.dpaw.wa.gov.au/browse/profile/29418
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.