If you hold a buttercup flower under your chin and your chin glows yellow, it is a sure sign that you are fond of butter, apparently. Actually it is because the petals have two flat epidermal layers of very reflective cells, separated by an air gap, which makes them doubly glossy and reflective. They also reflect a huge amount of UV light to attract pollinating insects.
The creeping buttercup, Ranunculus repens, and taller meadow buttercup, Ranunculus acris are yet more of my lawn “weeds” (perhaps I should call it a small meadow rather than lawn). They are good for bees and hoverflies, but toxic to people and domestic animals.
I shall leave you with an excerpt from Emily Dickinson’s poem, “Could I but Ride Indefinite“:
Could I but ride indefinite
As doth the Meadow Bee
And visit only where I liked
And No one visit me
And flirt all Day with Buttercups
And marry whom I may
And dwell a little everywhere
Or better, run away