Methods and compositions for the efficient transformation of duckweed are provided. Preferably, the methods involve transformation by either ballistic bombardment or Agrobacterium. In this manner, any gene or nucleic acid of interest can be introduced and expressed in duckweed plants. Transformed duckweed plants, cells, tissues are also provided. Transformed duckweed plant tissue culture and methods of producing recombinant proteins and peptides from transformed duckweed plants are also disclosed.