Coronopus squamatus (Forssk.) Asch. (Cochlearia coronopus, Senerbiera coronopus )
An annual or biennial herb, probably native, that occurs locally in waste and cultivated places, farmyards, pastures, along paths, in gateways and by roadsides, it is not usually troublesome. Swinecress is common in southern and eastern England but infrequent further north. It is not found above 1,000 ft. Swine-cress is characteristic of clay and prefers nutrient rich soil. It is tolerant of trampling. Leaf size and shape is variable.
The closely related lesser swine-cress, Coronopus didymus, is an introduced weed found on cultivated and waste ground. The origin is unknown but it was first recorded in Britain at the end of the 18th century. It is widespread especially in southern and eastern England but rarely abundant.
Swine-cress flowers from May to October. It can be found in fruit for 3 months of the year.
Seedlings emerge from February to October with peaks of emergence in April and September. Seed sown in May takes around 14 days to germinate.
There is no obvious seed dispersal mechanism. Swine-cress is often found around manure heaps.
Swine-cress is not considered a serious arable weed. Surface tillage and the cultivations associated with growing root crops should keep it in check.
In pasture, intensive grazing encourages the development of swine-cress.
Updated October 2007.