You may be familiar with field and hedge bindweed, both common climbing or spreading plants, but although carrying some of the same characteristics as these two in terms of leaf shape, stem colour and climbing nature black bindweed (Polygonum convolvulus) is not related. Black bindweed is more closely related to the dock family than to the convolvulus family. Closer inspection of the flowers will prove this point!
Black bindweed is a fast growing, climbing or binding, plant that entwines itself clockwise around the stems of stronger plants; it can grow to over a metre long. It is a plant almost entirely of arable fields winding its way through crops damaging the plant(s) it is climbing on and making harvesting difficult. As a result black bindweed is not a popular weed!
Apparently, like so many of our weeds, this was once an edible crop with the seeds being edible, but you need a lot of bindweed to harvest enough seed to make it viable! However, traces have been found in bronze age remains which show it was once valued even if that was around four thousand years ago.