Columbetta is the diminutive of columba, a dove; so called from the color of the plant.
Orcellus is a diminutive meaning a small cask; from orca, a cask.
It is the diminutive of pluteus, a shed or penthouse, from its conical cap.
Paludosella is a diminutive of palus, gen. paludis, a swamp or marsh.
Cantharellus is a diminutive from a Greek word meaning a sort of drinking-cup.