Wild or garden flower? ID please

[Pete Collins]

I've no idea what this is - not sure if it's a wildflower or something escaped from a garden (though it was 200+ yards from the nearest house).

It was in a hedgerow close to the river Chess on the Herts/Bucks border, between Latimer and Chenies. So the chalky soils of the Chilterns again, if that helps.

Thanks in advance for your help.

[aeshna5]

Common Wintercress, Barbarea vulgaris.

[Pete Collins]

Thanks aeshna5!

That was one I actually looked at in the little Collins Gem Guide (because it was yellow with four petals), but I didn't recognise it from the drawing!

I know its a common plant, but it's a new one for me.