Weeds in Australia

Search

Sisymbrium runcinatum

Description
 

African Turnip Weed (Sisymbrium runcinatum) is an annual herb that grows up to 50 cm tall. The stems arise from a basal rosette of leaves and either lie flat against the ground or grow obliquely upwards. The basal leaves are deeply and jaggedly lobed with the lobe tips pointing backwards to the leaf base. The upper leaves are similar in appearance to the basal leaves but diminish in size along the stems. The flowers occur in long, loosely-flowered racemes (elongated stem with flowers produced along its length). There is a small, leaf-like bract occurring just below each flower. The flowers consist of four, white to yellow petals with each petal up to 3.5 mm long. The fruits are long and narrow (1-3.5 cm long, 1-2 mm wide) and densely hairy. The short stalks that attach the fruits to the stem are held erect, causing the base of the fruits to be pressed against the stem. The seeds are small (about 1 mm diameter) (Hewson 1982; Rich 1991; Hussey et al. 2007).

For further information and assistance with identification of African Turnip Weed contact the herbarium in your state or territory.

Distribution:

In Australia, African Turnip Weed is only known to be naturalised in Western Australia where, it occurs in the Coolgardie, Yalgoo, Avon Wheatbelt and Geraldton Sandplains regions (Western Australian Herbarium 1998 -).

Habit:Herb
Key points:

  • African Turnip Weed (Sisymbrium runcinatum) is a prostrate annual herb to 0.5 m high.
  • It is similar to other cruciferous weeds so care should be taken with its identification.
  • It is a potentially significant weed in cropping situations but is as yet a relatively unknown weed in Australia.

How it spreads:

African Turnip Weed is an annual species, hence reproduction occurs by seed. Although no published information could be found on the dispersal mechanisms used by African Turnip Weed, it is assumed that it spreads in the same manner as other similar weedy cruciferous species such as Wild Radish (Raphanus raphanistrum) and Sand Rocket (Diplotaxis tenuifolia).

Theses species spread by water, especially where plants grow in riparian habitats and on steep terrain where erosion and runoff occurs. Contaminated soil, fodder, vehicles and other equipment are potential vectors for seed transport. Seeds may also be readily dispersed along roadsides during roadside maintenance works. Dispersal via contaminated agricultural produce is also a potential means of spread (Parsons & Cuthbertson 2001).

Where it grows:

In Western Australia, African Turnip Weed is found as a localised weed of road verges and granite rocks in the southern part of the state (Hussey et al. 2007). African Turnip Weed has been recorded growing on a range of soil types including clay, sand/loam and loam. It has been collected from various habitats including cropland, pasture, roadsides, open shrubland and eucalypt woodland (Western Australian Herbarium 2007).

Flower colour:

Yellow, White

Distribution map:

Western Australian Herbarium (1998-). FloraBase - The Western Australian Flora. Department of Environment and Conservation. Available at http://florabase.calm.wa.gov.au/browse/profile/3073 

Impacts:

African Turnip Weed is recorded as a weed of crops, pastures and in native bushland in Western Australia (Western Australia Herbarium 2007).

Origin:

African Turnip Weed is native to south-western Europe (Ball 1996) and northern Africa (African Flowering Plants Database 2007).

History:

The earliest records of African Turnip Weed in Australia are two herbarium collections taken from Mullewa and the Yilgarn Range in Western Australia in 1960 (Western Australian Herbarium 2007). It is not known how or why African Turnip Weed was introduced into Australia.

Photograph
 


More photos

Top

Disclaimer
This database is designed to provide information, including biological and ecological, on invasive plant species that are on a national weed list, or are legislated against in a state or territory. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. For further information on the images contained in the database please contact the copyright owner. All images in the weed identification tool are managed by the Australian Plant Image Index (APII). Various copyright conditions apply for these images. For further information on the copyright conditions of images contained in the database please contact the APII at: photo@anbg.gov.au.