Families (As per The Plant List)

 
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

H

Haloragaceae - 4 (Laurembergia coccinea, Myriophyllum oliganthum, Myriophyllum tetrandrum, Myriophyllum tuberculatum)

Hernandiaceae - 1 (Gyrocarpus americanus)

Hydrocharitaceae - 11 (Blyxa aubertii, Blyxa echinosperma, Blyxa octandra, Hydrilla verticillata, Najas graminea, Najas indica, Najas minor, Nechamandra alternifolia, Ottelia alismoides, Vallisneria natans, Vallisneria spiralis)

Hydroleaceae - 1 (Hydrolea zeylanica)

Hymenophyllaceae - 1 (Hymenophyllum exsertum)

Hypericaceae - 4 (Cratoxylum polyanthum, Hypericum gaitii, Hypericum japonicum, Hypericum mysurense)

Hypodematiaceae - 1 (Leucostegia truncata)

Hypoxidaceae - 4 (Curculigo capitulata, Curculigo orchioides, Curculigo trichocarpa, Hypoxis aurea)