27 LEMNA MINOR L.          1-6
   27 SPIRODELA POLYRRHIZA (L 1-6
   22 CERATOPHYLLUM DEMERSUM  1-6
   22 MYRIOPHYLLUM SPICATUM L 1-6
   17 LEMNA GIBBA L.          1-6
   16 SPIRODELA POLYRRHIZA (L 3-6
   15 LEMNA MINOR L.          3-6

   14 AZOLLA FILICULOIDES LAM 1-6
   11 POTAMOGETON PECTINATUS  1-6
    6 RANUNCULUS FLUITANS LAM 1-6
    6 POTAMOGETON LUCENS L.   1-6
    6 POTAMOGETON PERFOLIATUS 1-6
    5 CALLITRICHE OBTUSANGULA 1-6
    3 CERATOPHYLLUM DEMERSUM  4-6

    3 HELODEA CANADENSIS RICH 1-6
    3 LEMNA GIBBA L.          4-6
    3 POTAMOGETON PECTINATUS  4-6
    2 RANUNCULUS CIRCINATUS S 1-6
    2 POTAMOGETON FLUITANS RO 1-6
    2 AZOLLA FILICULOIDES LAM 3-6
    1 MYRIOPHYLLUM VERTICILLA 1-6

    1 SAGITTARIA SAGITTIFOLIA 1-6
    1 POTAMOGETON CRISPUS L.  1-6
    1 POTAMOGETON LUCENS L.   4-6
    1 POTAMOGETON TRICHOIDES  1-6