Brian had re-discovered Greater Lettuce Lactuca virosa which was first recorded in the county by Henry Spare in Leighton's Flora of 1841. Brian said "That record is not widely accepted, but I found L. virosa turning up on the side of the A5 at Preston (SJ 535 121) and Upton Magna (SJ 554 118), both in 2009".
Take a look at the distribution map here. If you pass the cursor over the screen, you can see which grid square you are on. And you can see the black dot on square SJ 51 which represents Brian's two records.
Brian wasn't able to get a photo of the plant so here is an illustrative plate courtesy of Mr. Google. If you want to see a fresh specimen, you'll just have to emulate Brian. Grab your "Poland" or "Stace" and get out plant-hunting this year. If you re-find something that hasn't been recorded for a few years, we can share it on this page and you will have added a black dot of your own to a BSBI distribution map!