mushrooms, especially in the wild have hugely varying potencies... that said, psilocybe subaeruginosa (as with all woodloving psilocybes) is rated as one of the most potent magic mushrooms in the world.
copelandia cyanescens are often close to, or as potent, however tend to lose plenty of their potency if handled incorrectly.
most would agree that sub's are around about twice the potency, or more, of your average cubensis - that's 1-2 dried grams providing a fairly strong trip!
also - small, more juvenile specimens of woodloving psilocybes tend to be much more potent than fully grown mature specimens. at some point in their growth, psilocin/psilocybin production slows down. so 1 dried gram of small specimens is most likely going to get you tripping a hell of alot harder than 1 dried gram of larger specimens.