A bristly, rough to touch, erect, annual or biennial plant with wiry branches, small, 4-petalled, yellow flowers in spring and narrowly conical, hairy pods, 8-20 mm long held vertically and very close to the stem. The rosette leaves tend to wither before flowering and have 3-5 pairs of lobes that point back toward the base of the leaf.
Description:
Cotyledons:
Two, lean against each other(incumbent). Oval, slightly indented tip, 5-8 mm long with a petiole of the same length, and is hairless. They hypocotyl is very short, and there is no epicotyl.
First Leaves:
Arise singly, the first being 8 to 12 mm long with a petiole approximately the same length. Moderately long hairs on the upper surface with longer hairs around the edges. The earliest leaves have shallow lobes and are round with an obtuse tip. As the plant develops the leaves elongate and become more lobed and ultimately very deeply lobed.
Leaves:
Forms a rosette 300 to 400 mm in diameter that normally withers as the plant flowers.
Stipules - None.
Petiole - On basal leaves, 50-70 mm long.
Blade - Up to 120 mm long by 55 mm wide, deeply lobed, usually with 3-5 pairs of lobes, the end lobe is rounded and much larger than the side lobes. Sides lobes point towards the base of the leaf. Lobes usually toothed. Tips rounded. Stiff reflexed (bent back) hairs.
Stem leaves - Alternate. Lower stem leaves about 200 mm long with pointed tips and stalked. Upper leaves are smaller and may be stalkless and are often arrow shaped. A few bent back hairs on the upper side, and more on the lower side especially towards the tip and on the veins. The stem leaves tend to be narrower and have fewer lobes than the rosette leaves and become smaller up the stem.
Stems:
Erect, wiry, woody, solid and pithy, rigid, circular in cross section, up to 1000 mm tall, lengthwise stripes, often reddish at the base. Numerous small white hairs and a few stiff, strong downward directed hairs. Spreading branches from the base and short laterals along their length almost at right angles to the main stem. Stems very wiry when dry.
Flower head:
Long and stout, paniculate racemes at the ends of stems.
Flowers:
Yellow, 3 to 8 mm in diameter on short stalks(pedicels).
Ovary - Stigma entire and stalkless.
Sepals - Erect, 2-2.5 mm long, hairy.
Petals - 4, pale yellow, 2-4 mm long
Stamens -
Anthers -
Fruit:
The seed pods are short, narrowly conical, 10 to 20 mm long by 1.5-2 mm wide at the base, 2 celled and held close and parallel to the stem by short, 1-3 mm long, thick stalks(pedicels). Valves 3 nerved with an obvious midrib and thick walled. Tiny persistent style on top. Hairy. Opens when ripe.
Seeds:
Many, orange-brown, egg shaped to elliptical and not flattened, 1.5 mm long by 0.8 mm wide, cut off at an angle on top, in 1 row. Surface dimpled. grooved and hairless.
Roots:
Strong taproot and many fibrous roots.
Key Characters:
Cotyledons incumbent.
Hairs simple.
Leaves smooth and hairless or with scattered hairs.
Petals pale yellow, not twisted and usually less than twice as long as the sepals.
Pedicel appressed to stem, 2-3 mm long.
Pod narrowly conical, erect, closely appressed to stem, hairy, 3 nerved, dehiscent, 10-20 mm long, at least 3 times long as broad, not beaked and persistent style very short, seeds 1 rowed.
Valves with prominent midrib, compressed from the back.
From J.M. Black, N.T. Burbidge and B.L. Rye.
Biology:
Life cycle:
Annual or biennial. Seeds germinate mainly in autumn with some in spring. It forms a rosette of leaves over winter and sends up a branched flowering stem in spring. It usually dies off in summer but some plants in moist conditions may survive into their second season.
Physiology:
Reproduction:
By seed.
Flowering times:
Spring in western NSW.
September to December in SA.
October to November in Perth.
Seed Biology and Germination:
Vegetative Propagules:
None.
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Spread by seed.
Origin and History:
Europe. Mediterranean. North Africa. Western Asia.
Distribution:
ACT, NSW, QLD, SA, TAS, VIC, WA.
Found in most parts of Tasmania.
Habitats:
Climate:
Temperate. Mediterranean.
Soil:
Plant Associations:
Significance:
Beneficial:
Honey plant.
Leaves and shoots edible.
Used in herbal medicine for colds and chest complaints.
Detrimental:
Weed of roadsides, cultivation, fallows, orchards, cereal or vegetable crops and disturbed areas.
It is moderately competitive and the hard and wiry mature stems can interfere with cereal harvesting.
May taint milk.
Relatively unpalatable.
Toxicity:
Not recorded as toxic.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Manually remove isolated plants.
Prevent seed set. Spray small infested areas with 500 mL/ha of Brodal in winter each year.
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:
African Turnip weed (Sisymbrium thellungii)
Indian Hedge Mustard (Sisymbrium orientale) is almost identical as a seedling. At the rosette stage the terminal lobe is more elongated and pointed. When mature it has larger flowers, longer seed pods at right angles to the stem.
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P138-139. Diagram. Photo.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P374. Diagram.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P181-182.
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P334. Photo.
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). P122. Photo.
Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P46-47. Diagrams.
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). #1137.3.
Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P169.