Poaceae The grass family including Cortaderia selloana (Pampas grass) and Miscanthus sinensis (Zebra grass)
I don't really think of members of the grass family as flowering plants, but of course they are. The grass family is huge with 780 genera divided into over 12,000 known species, making Poaceae the fifth largest plant family in the world. The grass family doesn't have pretty flowers because it doesn't need to attract insects. All grasses are wind-pollinated.
The grass family is ancient. Seeds from Poaceae species related to modern rice and bamboo have been found in fossilized dinosaur dung from the late Cretaceous period but the grass family really got going about five million years ago. New mountain chains (like the Rockies) created much larger dry habitats, ideal for the vast grasslands to develop. Today, just three species (rice, corn and wheat) provide half of humanity's daily calories.
I've never grown ornamental grass but one one of my neighbors has thoughtfully planted these two common species in the front garden. I know all about that combination of grass species we call a lawn and I've struggled with mine for thirty-five years. Incidentally, I'm giving away my rechargeable lawn mower next week because I've sold my house. The mower works just fine but I won't need it to mow my balcony. I'm moving at the end of the month to a fourth-floor condo.
It has come to this.