FRQ
   33 LEMNA MINOR L.          1-6
   29 LEMNA GIBBA L.          1-6
   28 WOLFFIA ARRHIZA (L.) WI 1-6
   24 LEMNA MINOR L.          3-6
   21 LEMNA TRISULCA L.       1-6

   20 LEMNA GIBBA L.          4-6
   19 SPIRODELA POLYRRHIZA (L 1-6
   16 LEMNA TRISULCA L.       4-6
   11 CERATOPHYLLUM DEMERSUM  1-6
    9 SPIRODELA POLYRRHIZA (L 3-6

    9 HYDROCHARIS MORSUS-RANA 1-6
    6 WOLFFIA ARRHIZA (L.) WI 5-6
    6 HELODEA CANADENSIS RICH 1-6
    4 AZOLLA FILICULOIDES LAM 1-6
    4 CERATOPHYLLUM DEMERSUM  4-6

    2 AZOLLA FILICULOIDES LAM 3-6
    1 POTAMOGETON CRISPUS L.  1-6
    1 HELODEA CANADENSIS RICH 4-6