Interim profile, incomplete information
General Impact
Rumex crispus, along with R. obtusifolius are troublesome weeds in grasslands, pastures and arable land. In agricultural areas R. crispus competes with sown or native pasture species and arable crops. They also occupy area which could be used by more palatable crop species (Cavers & Harper, 1964) and thus reduce forage feeding value. While leaves of R. crispus had only 20% less palatability than ryegrass, and similar protein concentrations to lucerne, rumicin and chrysaborin from above-ground parts and roots, respectively may cause gastric disturbances and dermatitis in cattle if eaten in large quantities. There are also concerns that nitrate and oxalic acid may cause fatalities in livestock (Reviewed in Zaller, 2004). The presence of both species are to some extent, indicators of mismanagement of land, of high soil nitrogen concentrations and with R. crispus, soil compaction. They are successful on agricultural land due to flowering several times a year, production of large amounts of seed which remain viable for many years, ability to quickly establish from seed and ability to germainte in a wide range of conditions. They can also regrow from vegetative fragments left in the soil (Cavers & Harper, 1964) While in general R. crispus is not common in native plant communities (Ellenberg, 1986 in Zaller, 2004) it is stimulated and distributed by human activities, and is an early coloniser of disturbed areas in lowland and upland. R. crispus may also serve as a host for diseases, pests and parasites.
Location Specific Impacts:Saint Helena 
Reduction in native biodiversity: The writings of Joesph Banks, Daniel Solander and Georg Forster who visited Saint Helena in the 1770's mentions the invasion of introduced species (lists include as many as 300 species) on pastures of intermediate elevation. Introduced species include Rumex crispus, gorse Ulex europaeus, Solanum nigrumRubus pinnatus. The 'Extinct in the wild (EW) native redwood Trochetiopsis erythroxylon was absent in these elevations (In Cronk 1983).
Threat to endangered species: The writings of Joesph Banks, Daniel Solander and Georg Forster who visited Saint Helena in the 1770's mentions the invasion of introduced species (lists include as many as 300 species) on pastures of intermediate elevation. Introduced species include Rumex crispus, gorse Ulex europaeus, Solanum nigrumRubus pinnatus. The 'Extinct in the wild (EW) native redwood Trochetiopsis erythroxylon was absent in these elevations (In Cronk 1983).
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