A annual herb to 400 mm tall, with star and simple hairs, a basal rosette of leaves and erect stems bearing heart shaped pods. It has small, white 4 petalled flowers in winter and spring.
Description:
Cotyledons:
Two. The cotyledons are oval, 4 to 8 mm long overall with a short petiole, rounded tip, tapered base and is hairless. The plant has a very short hypocotyl and no epicotyl.
First leaves:
The first leaves are paired. The first leaf is oval with a rounded tip, 5 to 10 mm long overall, hairy on both surfaces with a short, hairy petiole. It carries simple hairs, and star hairs, which can be distinguished only with the aid of a lens. The leaves are extremely variable in shape, the early leaves being oval with a scalloped or toothed margin.
Leaves:
Later leaves grow singly. Usually after the 4th to 6th leaf they develop deep lateral incisions cutting off a number of lobes in the middle of the leaf. In some cases, however, these lobed leaves are not produced. The plant develops as a rosette, which reaches 200 mm and occasionally 300 mm in diameter.
Stipules -
Petiole - In later leaves the blade often extends towards the base, and the petiole is much reduced, or entirely absent.
Blade - Variable from smooth edges to deeply lobed. Usually oblong in outline. 30-150 mm long by 7-75 mm wide. Tip rounded. Sides convex or lobed. Base tapered. Surface hairy.
Stem leaves - The stem leaves are lance shaped, approximately 40 mm long, smooth or serrated edges, sessile and clasping with basal lobes. They have simple and star hairs on the upper and lower surface.
Stems:
The stems are slender, branched, spreading, solid, up to 400 mm long and circular in cross section with shallow longitudinal grooves. Scattered star hairs occur along their length especially when young.
Flower head:
The inflorescence is a terminal, simple or branched raceme without bracts. The raceme is initially a dense cluster of flowers and elongates, up to 250 mm long, as the fruit develops.
Flowers:
The individual flowers are 3 mm in diameter and borne on 5-16 mm long slender stalks
Bracts - None.
Ovary -
Style - Very short, 0.25 mm long.
Sepals - Shorter than petals. Sometimes reddish in the upper part. 1.5-2 mm long.
Petals - Four white petals, 1.7-3 mm long, longer than sepals.
Stamens - 6, 4 nectary glands, one on each side of the outer stamens.
Anthers -
Fruit:
A distinctive flattened heart shaped, hairless, 2 celled, pod, 5-8 mm long by 5-7 mm wide, net veined on the surface. Borne horizontally on spreading stalks that are 8-17 mm long. Narrow septum. Valves are boat shaped, wingless and keeled. Expels seed when mature.
Seeds:
4-15 in each cell, exude mucus, egg shaped to oblong, orange to brown, 0.75 mm long, Surface hairless, grooved and with a honeycomb texture.
Roots:
Thin taproot.
Key Characters:
Biology:
Life cycle:
Annual. Germination occurs in autumn to early winter or spring. The mature plant is erect in habit with a rosette which, depending on competition at ground level, may persist for much of its life. It flowers in late winter to spring and dies in summer.
Physiology:
Reproduction:
By seed.
Flowering times:
August to October in SA.
June to November in WA.
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
WA specimens may be an intermediate form between C. bursa-pastoris and C. rubella.
Allelopathy:
Population Dynamics and Dispersal:
Origin and History:
Cosmopolitan temperate and sub tropical regions.
Distribution:
ACT, NSW, NT, QLD, SA, TAS, VIC, WA.
Shepherd's Purse occurs throughout Tasmania.
Habitats:
Climate:
Temperate and sub tropical.
Soil:
More common on heavy grey clays and red brown earths.
Grows on a wide range of soil types.
Plant Associations:
Bimble box and Black box communities.
Significance:
Beneficial:
Cooked stems and leaves formerly used as a vegetable.
Medicinal herb.
Detrimental:
Weed of fallows, arable crops, roadsides, lawns, gardens, pastures, and disturbed areas.
It is moderately competitive in young crops, but most soon overgrow it.
May taint milk.
May discolour egg yolks.
Relatively unpalatable and grazed sparingly.
Toxicity:
Horses have died from fibre balls after consuming large quantities.
Legislation:
None.
Management and Control:
Thresholds:
Generally doesn't cause significant yield losses in crops or pastures unless infestations are very dense.
Eradication strategies:
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:
It is commonly infested with white rust.
Related plants:
None.
The native Brassicaceae species usually have short, broad and smooth pods.
Plants of similar appearance:
Capsella pilosula has smaller pods (4 mm long by 2 mm wide) and bracts on the raceme.
Capsella rubella is very similar and has reddish sepals. WA specimens may be an intermediate form.
References:
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P131. Diagram. Photo.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P383. Diagram.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P188. Diagram
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P320. Photo.
Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P51. Diagram.
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). #246.1.
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). P162.