is a specific kind of: herb, herbaceous plant.

is a broader term that covers: meadow buttercup, Ranunculus acris, tall buttercup, tall crowfoot, tall field buttercup | common buttercup, Ranunculus bulbosus | Mount Cook lily, mountain lily, Ranunculus lyalii | Ranunculus occidentalis, western buttercup | creeping buttercup, creeping crowfoot, Ranunculus repens | celery-leaved buttercup, cursed crowfoot, Ranunculus sceleratus.

is a member of: genus Ranunculus, Ranunculus.