bitter dock
Bitter dock is native to Europe but is now widely distributed all over the world, growing in anthropogenic environments such as farm land, meadows, waste ground, roadsides, and ditches. At Salter Grove, bitter dock is confined to the drier upland areas such as on the lawn south of the parking area. It bears a great resemblance to its close relative curly dock which prefers habitats near water and grows along the Marsh Trail and Causeway.
Despite its unpalatable sounding name, it is used in European countries for various food preparations. The leaves are used in salads, or used like spinach. The abundant seeds are used as a spice.
For more information:
https://gobotany.nativeplanttrust.org/species/rumex/obtusifolius/
https://www.illinoiswildflowers.info/weeds/plants/bitter_dock.htm
http://www.florafinder.com/Species/Rumex_obtusifolius.php
https://en.wikipedia.org/wiki/Rumex_obtusifolius
https://www.ediblewildfood.com/bitter-dock.aspx
Millspaugh, C.F. (1974). American Medicinal Plants. Dover Publications, Inc. pp. 577-579. (Original work published in 1892)