Ranunculus spp. / Buttercup Family
Hold a buttercup under your chin, if it shines yellow, it means you like butter! Actually, since the flowers have shiny petals, EVERYONE would appear to like butter! Buttercups contain a glycoside toxin which can be a skin irritant, so handle them with care if you try the flower-under-the-chin trick! I've done that test on many a kid and never had a problem with it.