My observation is that spring flowering buttercups will grow very short if in grown amongst grass that is regularly mown and very tall if grown amongst long meadow grasses. Ranunculus bulbosus grows plentifully in the verges around where I live but at this time of year the the local council workmen are busy cutting the grass and that's the end of the buttercup flowers. Although the buttercups are still in full flower when cut, I guess mowing still spreads enough viable seed for them to survive.
