This word for a cluster of trees or a clod of soil may come from the Dutch for "lump"
... [158090; akin to Dutch klompe lump, mass, Old English clympre lump 
of metal] ... an unshaped mass; a heap; a cluster of trees; a tuft of shrubs; a 
compact... [DOC] [TLE] Clods - definition of clods by The Free Dictionary [PAR] Define clods.