A couple of months ago I looked briefly at some of the weeds growing on a well cultivated part of the allotment and found that though there was a range of plant families, the most common species was Veronica persica. This photo shows a the inhabitants of a more established bed that had not been weeded for a few years. From the left there is Couch Grass or Twitch Elytrigia repens, Dandelion Taraxacum agg, Dock (probably Rumex obtusifolius), Creeping Cinquefoil Potentilla reptans and Creeping Buttercup Ranunculus repens. Not shown is the ubiquitous Horsetail Equisetum arvense.
V persica is hardly present and the title for the most apparently dominant plant is now taken by Potentilla reptans. This chap is incredibly difficult to weed because it tends to break off at the surface leaving the tough wiry roots behind. It spreads rapidly with runners that root readily where they land and it ingratiates itself with garden plants so that the two cannot be separated. The use of runners is a strategy common amongst the Rose family (Rosaceae), for example bramble, but it is used successfully by other families. Ranunculus repens (Ranunculaceae) spreads in much the same way.