In my yard: goosefoot (aka lambsquarters or Chenopodium album), pigweed (Amaranthus retroflexus), purslane, carpetweed, plaintain, dandelion, goatsbeard, jewelweed, Canadian thistle, black nightshade, goldenrod, ragweed, stinging nettle, horsetail, Japanese knotweed, wood sorrel (aka 'sweet clover'), white clover, shepherd's purse, prostrate spurge (one of the few I actively dislike), creeping charlie (or creeping jenny or ground ivy), crabgrass, Queen Anne's lace, pokeweed, knotgrass, daisy fleabane, and I'm sure many more. I think all of these except jewelweed and purslane are introduced (invasive) species. This isn't too surprising considering these weeds are adapted to my lawn, garden areas, and the disturbed edge of a soybean field/sump pump drainage ditch/creek behind the yard.
I know there were native chenopods and amaranths; I have some lovely Mexican amaranth (pigweed) volunteers. But the really agressive ones here are the European varieties.
A flowering weed;
Hearing its name,
I looked anew at it.