Trithuria cowieana is a species of aquatic plant in the family Hydatellaceae endemic to the Northern Territory, Australia.

[1] Trithuria cowieana is an annual aquatic plant with linear, max.

The plant turns red, once it reaches the flowering stage.

[2] It is a monoecious species with bisexual reproductive units ("flowers").

[2] It occurs in swamps,[2] and in sand along roads and vehicle tracks.