Hydrocharitaceae

Partially or wholly submerged herbs, sometimes marine Hydrocharitaceae

Ovary inferior; male flowers with more than 1 stamen

Fresh water plants

Leaves cauline, opposite or whorled, on elongated occasionally branched submerged stems with adventitious roots. Flowers unisexual, axillary

Leaves serrulate, often crisped on the margins. Styles undivided, free to the base Hydrilla

Leaves with entire or minutely denticulate margins. Styles in female flowers lobed or notched