Grass blades, coffee or cacao leaves . . . probably all plants
"You've mistaken a fungus for a pine tree" can be a ticklish thing for one botanist to say to another. Yet, in the 1990s, one respected university researcher made that very accusation to another. Stories such as this have spiced botanist gossip for years, but in this case, the two scientists resolved their differences and published a paper telling the whole story.