When it comes to weeds of cultivation I guess there are few so widespread and vigorous as broad-leaved dock (Rumex obtusifolius). It is the most sturdy and imposing of the dock family with stout stems, large leaves and elongated flower spikes; it is quite easily recognised as being different to its cousins.
Broad-leaved dock can be found on disturbed or bare ground anywhere including farm fields, spoil heaps, hedgerows, waste ground, river banks, even coastal shingle beaches. Growing to over a metre tall, sometimes even bigger it can also in less favourable conditions be as small as one foot tall. The heart shaped leaves are always large being six to eight inches long. The small, yellowish brown flowers occur in whorls around the stem and can extend some distance along the stem; they are visible from May right through until October.
The leaves contain chemicals that are believed to soothe nettle stings and are used also in the treatment of burns and blisters. It is sometimes known as bitter of butter dock.