Wall Rocket

Diplotaxis muralis (L.) DC.

Synonyms - Brassica muralis

Family: - Brassicaceae

Names:

Diplotaxis is from the Greek diplos meaning double and taxis meaning row and refers to the 2 rows of seeds in the pod.

Muralis

Other Names:

Annual Wall Rocket

Dog Weed

Goat Weed

Nanny Weed

Sand Mustard

Sand Rocket

Stink Weed

Stinking Billy

Teetulpa Weed

Wall Mustard

Summary:

An annual or biennial, erect or spreading herb with 4 petalled, yellow flowers at any time of year that produce 2-4 cm pods with a short beak and 2 rows of seeds. The lobed leaves are mainly basal and emit a strong unpleasant odour when crushed.



Wall Rocket is an annual or biennial, erect or spreading, herb to 0.5 m high with stems that are bristly towards the base. The lobed leaves are mainly basal and emit a strong unpleasant odour when crushed. The flowers have 4 petals that are yellow and 4-9 mm long. The seed pods are 20-40 mm long with a short beak and 2 rows of seeds. It is scattered from Shark Bay to Esperance and flowers from mainly from summer to early spring.

Description:

Annual or biennial herb

Cotyledons:

Two. Round to oval. Tip round to flat. Edges smooth. Base tapered. Hairless. Petiole as long or longer than blade.

First leaves:

Oval. Tip Round. Edges irregularly toothed. Hairless. Veins not prominent. Petiole longer than blade.

Leaves:

Form a rosette or clusters up the stem or separate. Often yellowish green.

Stipules -

Petiole - about as long as the blade.

Blade - Variable, lobed or toothed, thin, 30-110 mm long by 5-25 mm wide. Unpleasant odour when crushed. Sparse stiff hairs mainly on the edges and petiole. Tip rounded to pointed.

Stem leaves - Oval, toothed or lobed becoming somewhat shorter up the stem. Short petiole.

Stems:

Flower stem - Erect, 100-600 mm tall. Usually bristly hairs on the lower portions.

Flower head:

Cluster or raceme at the ends of stems.

Flowers:

4 petals, pale yellow, 8-16 mm diameter.

Ovary - Stalkless.

Sepals - 4. Erect, 3-4 mm long.

Petals - 4. Yellow often becoming purple with age. 4-8 mm long. Overlapping.

Stamens -

Anthers -

Fruit:

2 celled cylindrical pod, 15-45 mm long by 1-3 mm diameter with many seeds and a seedless, conical beak about 1-2.5 mm long. Pod constricted between the seeds. Opens and releases seed when ripe. Pod stalk (pedicel) 5-20 mm long, usually about on third the length of the pod and held away from the main stem. 2 rows of seeds on each side of the membrane (septum) dividing the pod.

Seeds:

Tan to red brown or yellow brown, globular to egg shaped, small, about 1.2 mm long by 0.6 mm wide. Surface smooth, dull and hairless.

Roots:

Slender taproot.

Key Characters:

Cotyledons conduplicate

Typical form annual.

Stems with bristly hairs.

Petals yellow

Pod (siliqua) dehiscent, at least three times long as broad.

Pods compressed with a short beak.

Seeds in 2 rows

Adapted from John Black.

Biology:

Life cycle:

Annual or biennial. Seeds germinate from autumn to spring.

Physiology:

Reproduction:

By seed.

Flowering times:

Most of the year in western NSW.

Most of the year in SA.

January to August in WA.

Seed Biology and Germination:

Vegetative Propagules:

Hybrids:

Variety Babingtonii is biennial or perennial, larger, more leafy, the stems are always somewhat hairy ant the style is broader and shorter.

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

Mediterranean, Western, Central and Southern Europe, South Africa, New Zealand, North and South America.

Distribution:

ACT, NSW, SA, TAS, VIC, WA.

Habitats:

Climate:

Temperate.

Soil:

Mainly on sandy soils and limestone areas

Plant Associations:

Significance:

Beneficial:

Does not host Root Lesion Nematodes (Pratylenchus neglectus or thornei) 63

Detrimental:

Weed of disturbed areas, roadsides and occasionally crops and pastures.

May taint milk and meat but generally not grazed by stock.

Toxicity:

Not recorded as toxic.

Symptoms:

Treatment:

Legislation:

None.

Management and Control:

Encourage vigorous growth of other pasture species.

Grazing does not provide control.

Thresholds:

Eradication strategies:

Mechanical removal for several years is effective on small areas.

For larger areas 0.5 g Eclipse® plus 10 mL Brodal® in10 L water applied each year before flowering will provide control of existing plants and leave a soil residual to control later seedlings.

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:

None reported.

Biological Control:

Related plants:

Sand Rocket (Diplotaxis tenuifolia) is larger and perennial with hairless stems and larger flowers and pods. The pedicel (pod stalk) is longer and usually about the same length as the pod and it has an obvious stipe (small stalk between the pedicel and pod). All leaves have petioles.

Plants of similar appearance:

Radish, turnips, mustards, flatweed.

References:

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

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P378. Diagram.

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P322. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume . P. Diagram.

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). P118.

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

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #354.1.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P164.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P67 Diagrams. Photos.

Acknowledgments:

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