I've seen a few plants which confused me as leaves and flowers did not seem to match - until I realized they were two different plants but growing through each other - what I like to call Frankenstein plants.
The first one I saw that made me think of the name, "Frankenstein" plants, hemlock water dropwort and smooth sow thistle.
Sept 2021
hawkweed oxtongue and smooth sow thistle
gallant soldier and smooth sow thistle
smooth sow thistle and pellitory-of-the-wall
end of August 2021, annual wall rocket and Oxford ragwort
hoary mustard and hawkweed oxtongue rosettes
another example of hoary mustard and hawkweed oxtongues rosettes growing together
petty spurge growing through smooth sow thistle
thale cress and greater celandine
one I saw in my garden, claytonia and delphinium