Flowers are for insects and the flowers you buy from the florist are eugenic monstrosities that in an entomological episode of Snog, Marry or Avoid would get a 100% avoid rate.
Street plants, real plants, have beauty not for their flowers but for the variation of their strategies, the history of their travels and the intricacies of their survival. You do not study urban wild plants to find rarities, though you wouldn't want to miss them, and you never tire of the common plants. The only goal is to learn about what is out there.
Plants are outside and so must you be.
Plants are everywhere and so can you be.
Early on I met a woman with verifiable botanical skills, "she knows her plants". This was at a plant finding expedition near a train station and after taking the first corner we came across a grassy sloped patch with a rosette she, Oh Shock, did not recognize. That is how enormous you can find the world in one little, secluded and everyday place. That is when I learned that the study of wild plants is a process that takes a lifetime. So I take it slow and don't worry about not knowing the name of a plant. It will come to me.
The study of wild plants begins with identification but that is only the way in. Once you know its name you know you can recognize it next time you see it. Once you have seen it twice you can enter into the history (where is it from) and the geography (why is it here) of the plant itself and the place it grows in.
Plants watcher are a nerdy bunch and they have collected data, described places and wrote travel guides for centuries. You know things have gone wrong when you rate a book for the inclusion of plant lists.
My favourite book is the "New Atlas of Dutch Flora" that gives the historic distributions for 1500 individual plants.
But I could not do without many other books, especially the books that take you back to the Utrecht of 1843 or to the Terschelling of 1886 or the Amsterdam of 1975. Often the archaic language alone works miracles.
To speak about plants as a way into something else is all good but the pleasure of seeing a plant is what drives it.
I have not yet used the words 'nature', 'environment' and 'ecology' but they enter the story as well, somewhere.
Plants are just a tiny aspect of urban life but their study gives so much context in so many ways to my surroundings that I now can't imagine ever forsaking it.