Broad-leaved Dock - Rumex obtusifolius

Medium to tall erect plant to 1 metre. The leaves large and oblong, the lower heart shaped at the base wavy-edged. The flowers in spreading branches, leafy below. Fruit valves triangular, toothed often only one valve swollen.

other docks

one well developed smooth tubercle, valves with long lateral teeth

The fruits have a central part, triangular in cross-section, with three membraneous valves surrounding a small, hard 'tubercle'.  The shape and arrangement of valves and tubercles is diagnostic, and close-up photos of fruits and leaves/general habit is needed.

Waste and disturbed ground, poor quality pastures.

June to October

Perennial

Very common throughout Britain and a scheduled injurious weed.

Very common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 605 of the 617 tetrads.

In the current Checklist (Jeeves, 2011) it is listed as Native, Frequent

http://www.kenadams.org.uk/esb/Docks.htm