just want to say, i've always used them. as material components for spells or foci. or for the creation of magic items.
not only human, demi-human, and humanoid heroes/saints/villians... but also animals, elementals, whatever...
The Great Druid commands you to gather the remains of the Hart of X Forest burn and scatter them about the Forest.... while Archmage Y needs them for creating a pair of boots which will allow the wearer to travel thru even thick brush unhindered... and High Priest W wants them for prolonging a special rite during High Feast...