This is one of those yellow, usually spring flowering crucifers which are very tricky to identify. In this case the seed pods are upright and adpressed to the stem but don't have a seed in the beak at the end. As for the insect in the picture - a total fluke. It flew in and landed just as I took the photo.

The seeds when mixed with White Mustard (Sinapis alba) are ground into mustard flour for use in various mustard condiments. Mixed with water mustard flour makes English mustard and with vinegar it makes Continental Mustard.

This plant is very common in England and Wales but record become scarce the further north you go and it is rare in northern Scotland and uncommon in Ireland.

LHS: Banks of River Wye 6th September 2005 RHS Waste ground nr Cobh, Ireland 23rd June 2007

Added on September 18th 2005, updated 4th November 2008, updated 5th March 2010, updated 28th July 2013