That’s a plant but more like a weed. I have had it infiltrate my garden plot by blowing in from my neighbor’s plot. They grow plentiful and tall.

It’s an ornamental variety of amaranth. If it were the native type and it were in your cornfield it would be called Pigweed. The seeds are small and get into (and grow out of) cracks. If someone put seeds in those cracks intentionally they’re both brilliant and lucky. More likely volunteers from some that were in the vicinity last year.

Weeds are plants… Just like herbs are weeds are plants. At any rate, these are popping up all around town. I don’t know why people think they are pretty. They are just purple weeds. I for one don’t care for them.

A “weed” is simply a plant that isn’t valued/appreciated/liked where it is growing, so the “plant or weed” question is wholly subjective. I you like it where it is, it’s not a weed. Intention is irrelevant to the “plant or weed” determination. I have several plants in my garden that pop up in different spots each year as volunteers from prior years (e.g., bronze fennel), which I love and care for as “plants.” I also cultivate at least one tuft of crabgrass (Digitaria) into an ornamental “plant” each year, while treating the rest of the crabgrass that springs up in my yard as a weed and tearing it out. “Weed” is in the eye of the beholder.

Those amaranth plants are very cool. Amazing that these grew out of a crack in the sidewalk and understand not everyone would appreciate them there. I’ve seen these in pots on 7th St NW and in a garden of the senior center (?) at NH Ave and Randolph St NW. They spread by seed and early in the year there are a lot of seedlings around. They get flowers made up of heads of thousands of tiny flowers that look a lot like a celosia plant. The flower heads are a dark burgundy color and very beautiful. I’ve been meaning to buy seeds of these – there are varieties called St. Joseph’s Coat (rainbow colored leaves) and Love Lies Bleeding (gets drooping flower heads in pink and red). I like that they’re unusual and interesting colors. Plus they do very well in DC’s heat and humidity.