This is rare indeed! The plant they call Pritcher's Porritch. See the pods, containing some thick, lumpy substance? I've only ever read about this. Its properties have never been classified, but they're rumoured to be dangerous. Collect a sample, but be careful how you use it!"
-- Zygmunt Budge (BoP)
Possibly a British colloquial pronunciation of "Preacher's Porridge," perhaps meaning a plant eaten by the clergy
While the plant is sometimes called "Preacher's Porridge" by fans who only heard the words spoken in the game, the correct spelling of "Pritcher's Porritch" was confirmed by Harry Potter Wiki from Book of Potions game files.