yellow dock rumex crispus(check) which in common in England 
   
 dock? The name Dock is applied to a widespread tribe of broad-leaved wayside weeds, having roots possessing astringent qualities united in some with a cathartic principle, rendering them valuable as substitutes for Rhubarb, a plant of the same family (I think this is the reference) 
   
   
  

http://health.howstuffworks.com/
yellow-dock-herbal-remedies.htm dock
 Rumex crispus (L)

Synonyms: curled dock, narrow dock, narrow-leafed dock, garden patience, sour dock, rumex.

Order: Polygonaceae

Description: The identifying characteristics of Rumex crispus are the narrowness of the leaves, usually curly along the long edges, and the deep yellow colour of the root when scraped. It is a native perennial British herb found in arable farmland, on roadsides and in ditches and waste places throughout the world. Its spindle-shaped taproot sends up a smooth, slender stem, up to a metre in height. Lanceolate to oblong-lanceolate in shape, the pointed light green leaves have predominantly wavy margins. The lower leaves are larger and longer-petioled than the upper leaves. Blooming from June to July, the numerous pale green, drooping flowers are loosely whorled in panicled racemes. The fruit is a pointed three-angled and heart-shaped nut.