That's a very old music hall joke. The wild is some wild flowers growing locally. The first our councils contribution to the environment - sow wild flower seeds and reduce mowing to encourage bees and butterflies, and cut costs at the same time (except managing a wild flower meadow does need a bit of skilled work). Poppies, cornflower and oxeye daisies
The second is of flowers springing up naturally along the river bank. Purple loosestrife in the foreground and theres some rosebay willow herb in there as well.
Purple loosestrife is good stuff to have on an English river bank, feeding bees and butterflies. But I just read that it is an invasive weed in the US, not palatable for local insects. Rosebay willowherb was probably the first flower I took notice of. It grew in profusion on the bomb sites of London (of which there were still plenty when I was a child, and on which we played always hopeing we might find a bomb, or buried treasure) and I would pick a bunch to take home. To some they were weeds, but they have a lovely name, and a lovely flower.