Turnip Weed

Rapistrum rugosum (L.) All.

Synonyms - Myagrum rugosum

Family: - Brassicaceae.


Rapistrum is from the Greek rhapis (or Latin rapa) meaning Rape or Turnip and astrum meaning looks like hence it is a plant that looks like Rape.

Rugosum is Latin meaning rough and wrinkled and refers to the wrinkled upper segment of the fruit.

Turnip Weed because it is a weed of the Turnip family with a characteristic odour of the Turnips.

Other names:

Giant Mustard

Jointed Charlock


Wild Charlock

White Charlock

Wild Turnip.


Rapistrum has a rosette of large lobed, stalked, often bristly leaves. It is an annual to biennial plant with leafy, erect stems bearing yellow flowers usually in spring that are 10-20 mm in diameter with 4 petals and 6 stamens. The distinctive pod is 5-10 mm long has a cylindrical base with 0-2 seeds and a globular, ridged upper section with one seed and a short beak. The fruit is held close to the stem.

Native Europe it is a common weeds of roadsides and disturbed areas near cultivation but rarely invades bush. Most flower from autumn to spring.



Two. Heart shaped. Tip indented. Sides convex. Base tapered to squarish. Surface hairless. Petiole about the same length as the blade.

First Leaves:

Oval, tip round, edges toothed. Stalked. Hairy.


Alternate. Forms a basal rosette. Turnip odour when crushed.

Stipules - None.

Petiole - On lower leaves with longer hairs than the leaf.

Blade - Oval in outline, 80-250 mm, bluish green, deeply lobed with usually 3 pairs of side lobes and a much larger end lobe, irregularly and coarsely toothed edges. Acute tip on end lobe. Hairy to bristly.

Stem leaves - Usually narrower, lance shaped and without lobes but may be toothed. Upper leaves usually have no leaf stalk.


Erect, 150-1200 mm, stiff, branched. Lower portion has stiff, bristly hairs. Upper portion has shorter hairs. Turnip odour when crushed.

Flower head:

Panicle-like arrangement. Flowers and fruit borne on short 2-4 mm stalks on the ends of branches.


Yellow on short erect stalks.

Ovary -

Sepals - 3-5 mm long.

Petals - 4, pale yellow with dark veins, 5-10 mm long.

Stamens -

Anthers -


5-10 mm long (without beak) on erect, short, 2-5 mm long by 1 mm wide stalks that are held close to the stem. Top section globular and 3-6 mm long by 3-4 mm diameter, wrinkled and ribbed, 1 seeded with a conical, sometimes hairy beak. The beak is formed from the style and as long as the pod or 1-3 mm long. The lower section is cylindrical, 2.5-3.5 mm long by 1 mm diameter with 0-2 seeds. Alternate up the stem. 1-3 seeds per pod, lower section of pod may not have a seed. Pod does not release seed when ripe.


Egg shaped, yellow-brown, dimpled, 1-2 mm.


Branching, short taproot with many laterals.

Key Characters:

Cotyledons conduplicate.

Pod longer than broad, cylindrical or conical, usually splitting transversely into 2, indehiscent, superposed, usually single seeded articles.

Upper globular article with a short blunt beak.


Life cycle:

Annual or biennial. Germinates autumn to winter and forms a rosette of leaves. An erect, leafy flowering stem emerges in early spring and soon forms flowers. The pods mature in early summer and are often harvested with the cereal crop that it often infests. The plant usually dies with the onset of summer drought but under moist conditions may survive into the second season.



By seed.

Flowering times:

May and August to November in WA.

Late autumn to spring in western NSW.

October to December in SA.

Seed Biology and Germination:

Vegetative Propagules:




Population Dynamics and Dispersal:

Spread by seed mainly as a contaminant of grain.

Origin and History:

Central and southern Europe. North Africa. South west Europe.





Warm Temperate. Mediterranean. Sub tropical.


Wide range.

Plant Associations:

Wide range.




Honey plant.


Serious weed of wheat.

Weed of winter crops, cultivation, firebreaks, roadsides, railways, pastures, urban bushland and disturbed areas.

Causes yield reductions due to competition.

Contaminates grain.

Fibrous stems choke harvesters.


Taints milk, meat and butter.

Rarely toxic.


Noxious weed of WA (Pest plant in Esperance).

Management and Control:

Cultivation and delayed planting usually gives reasonable control. Hormone and other herbicides provide high levels of selective control in cereal crops.


1 plant/m2 can contaminate cereal grain.

10 plants/m2 often causes a cereal yield loss of around 10%.

Eradication strategies:

Remove isolated plants manually before flowering.

Treat small areas with a mixture of 500 mL/ha of Brodal plus 10 g/ha of Eclipse in winter each year until the plant disappears.

Most of the Brassicaceae weeds have dormant seeds that continue to germinate throughout the season and for several years. They often mature and set seed very quickly. Manual removal is effective but must be done at least every 8-10 weeks. Once pods are formed, seed will often mature even if the plant has been uprooted. Soil disturbance often leads to a flush of seedlings.

Many are somewhat unpalatable, so grazing only offers partial control. They often flourish in undergrazed, sunny areas.

In bushland situations, fairly selective control can be achieved with 100 mL spray oil plus 0.1 g Eclipse® or 0.5 g Logran® in 10 L water. 5 mL Brodal® is often added to this mix to provide residual control of seedlings. Spray the plants until just wet from the seedling stage up to pod formation.

Isolated plants should be removed manually and burnt if flowering or seeding and a 10 m buffer area sprayed with 10 mL Brodal® in 10 L water.

500 mL/ha of glyphosate(450g/L) can be used at flowering to reduce the seed set of most species on roadsides without causing significant damage to most native plants.

Wick application with 1 part glyphosate(450g/L) in 2 parts water or overall spraying with 100 mL glyphosate(450g/L) in 10 L water provides reasonable control of most species though Wild Radish tends to regrow.

Herbicide resistance:

Biological Control:

Related plants:

None in the same genus.

The native Brassicaceae species usually have short, broad and smooth pods.

Plants of similar appearance:

Wild Radish (Raphanus raphanistrum) is very similar and very difficult to distinguish at the cotyledonary stage.

Indian Hedge Mustard, Wild Turnip, Capeweed.


Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P136. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P388. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P330. Photo.

Gilbey, D. (1989). Identification of weeds in cereal and legume crops. Bulletin 4107. (Western Australian Department of Agriculture , Perth). P44. Diagrams. Photos.

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). P120. Photo.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #1045.1.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P351-352. Photos.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P83. Diagrams. Photos


Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.