Lacking dandelions in London

I am working in London this week - not the nice leafy park areas but gritty, run down Hoxton today. There are no dandelions anywhere, either in nature or in other people's art! Which has me thinking about where all the colour went in our cities? Specifically of course, where did the yellow go? ( That at least is a working quilt title - where does it go between bright flower and white seed head anyway?). Maybe I will superimpose dandelions on a cityscape. Of course maybe I won't because I am just starting to think.... but I do wonder - of all these people teeming past me on the street and streaming out of tube stations, how many are thinking obsessively about dandelions?