Although sometimes found near saltmarsh and dunes you are most likely to encounter red goosefoot (Chenopodium rubrum) down on the farm; it thrives in disturbed, nutrient rich soils with a particular fondness for manure heaps! The Chenopodium family in Britain consists of about nine species (some of which are quite rare nowadays) and they are similar to the Atriplex family which provide another seven species one might encounter and they are all quite similar in my estimation. The advantage of red goosefoot is that it has a beetroot coloured stem and a red tinge to the flowers. That said there are other reddish coloured members of the family but they seem to be pretty rare so that is not something I would bother myself with!
Along with these relative species, red goosefoot is considered a food plant in some cultures and is grown for that purpose whereas here, where it could grow freely if allowed, we try to rid ourselves of it. One of the ironies of modern agriculture perhaps?
Read more: Red Goosefoot: agricultural irony | Nature Notes from Dorset