What is "trithuria"

Trithuria is a genus of small aquatic herb, which represent the only members of the Family Hydatellaceae found in India, Australia, and New Zealand. Most of the 12 formally characterised species of Trithuria are found in Australia, with the exception of T. inconspicua and T. konkanensis, which are found in New Zealand and India, respectively.

These diminutive, moss-like, aquatic plants are the closest living relatives of the two closely related families Nymphaeaceae (water-lilies) and Cabombaceae. Together, these three families compose the order Nymphaeales in the APG III system of flowering plant classification. Trithuria (Hydatellaceae) diverged from the rest of Nymphaeales soon after Nymphaeales diverged from its sister taxon, which comprises all of the flowering plants except the two orders Nymphaeales and Amborellales.