The distribution of Rorippa sylvestris, creeping yellow cress in South Australia

摘要

Rorippa sylvestris (L.) Besser (creeping yellow cress) is a member of the mustard family and has been recorded in South Australia in 1986 and Tasmania in 2000. It closely resembles the co-generic species R. palustris (L.) Besser (marsh watercress), aperennial of 1-2 years that has been recorded in similar habitats as R. sylvestris. Confusion between the two species has been noted. This survey found R. sylvestris only occurred at Aldgate Creek and not at the River Murray as previously recorded. The infestations were found to extend over 2.3 km along the Aldgate Creek and its tributaries. Populations of the plant varied in number from several to approximately twelve thousand in eighteen locations.