A very odd Linaria

A very odd Linaria

Observation - A very odd Linaria - UK and Ireland. Description: So - the base of the stem appears normal - it then flattens going up the stem - almost as though the

So - the base of the stem appears normal - it then flattens going up the stem - almost as though there has been a mutation of some kind - with a screwed up mass of buds at the end ; I've included a picture of the end of an adjacent plant of the same species for comparison. What's going on here? - grateful for a proper botanical answer as this looks very strange!