Coronopus is the Greco-Latin name for a cress like plant and is from the Greek words korone meaning crow and pous meaning foot and refers to the crows foot like leaf arrangement.
Swinecress.
Other names:
Wartcress
Summary:
A light green divided leaf, low lying annual to biennial herb with pods that look like dog balls.
Description:
Cotyledons:
Two.
Leaves:
Petiole - Yes.
Blade - Light green, lobed to pinnate, with 3-5 pairs of deep lobes that are narrow and smooth edged or with cut segments. 6-25 mm long by 4-12 mm wide. Base tapered. Surface hairy or hairless.
Stem leaves - Pinnate with a short petiole, and hairless. Becoming stalkless and without lobes towards the top of the stem.
Stems:
Hairless. Light green. Low lying.
Flower head:
Raceme. Shorter than the leaf it is next to.
Flowers:
White. Small.
Ovary -
Sepals - persistent.
Petals - longer than sepals.
Stamens -
Anthers -
Fruit:
Pod 4 mm wide. On stalks shorter than the pod. 2 kidney shaped, deeply wrinkled lobes or cells that are notched at the base, rounded at the top and don't usually divide. Flattened. One seed in each cell.
Seeds:
Remain in pods.
Roots:
Key Characters:
Fruiting raceme shorter than leaf. Pod reniform, rounded on at summit.
Biology:
Life cycle:
Annual or biennial. Flowers October to February.
Physiology:
Reproduction:
By seed.
Flowering times:
October to February in SA.
Seed Biology and Germination:
Vegetative Propagules:
None.
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Spread by seed.
Origin and History:
Mediterranean.
Distribution:
SA, TAS, VIC.
Habitats:
Climate:
Temperate.
Soil:
Plant Associations:
Significance:
Beneficial:
Detrimental:
Weed of disturbed areas.
Toxicity:
Not recorded as toxic.
Legislation:
None.
Management and Control:
Thresholds:
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:
Related plants:
Lesser Swinecress (Coronopus didymus) is very similar but the fruit splits into 2 nutlets when mature and the flowering structure is longer than its opposite leaf.
The native Brassicaceae species usually have short, broad and smooth pods.
Plants of similar appearance:
Swinecress is difficult to distinguish from Cotula except when seed or flowers are present. The 'cressy' smell of Swinecress is distinctive, as are the small cotyledons of Cotula if present, but these do not usually persist. Though generally very similar there are differences in leaf shape; the terminal leaflet of Cotula often has three lobes while that of Swinecress is often single, and the leaflets on Cotula are usually pinnately lobed while the leaflets of Swinecress tend to have lobes on one side only and not pinnately paired lobes.
References:
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P387.
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). #354.2.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.