British Herb which Lets You Survive 5 days Without Food and Water

by Mezza

A few years ago i saw on some TV program a man described eating a little flower ( i seem to remember it was blue or purple).

It had the effect that the one who takes it can go on for longer periods without food or water. I think he said the ancients used to take it and go 5 days without a meal, and he had once tried it and went w/o food and water for 2 days.

Anyway, I would like your help to help me find the name and identify this flower. The plant was most defininatley a native british plant.

I am not entirely sure, but if it helps, I'm about 45% sure the program was an episode of BBC's Countryfile from 2006. Maybe featuring someone called Marcus Harrison.

Please help me find out what this was, names of hunches, links, or even similar plants with similar effects.

Thanks