Spirodela punctata is a species of duckweed (Lemnaceae). The species is morphologically intermediate between Lemna

Lemna

Lemna is a genus of free-floating aquatic plants from the duckweed family. These rapidly-growing plants have found uses as a model system for studies in community ecology, basic plant biology, in ecotoxicology, in production of biopharmaceuticals, and as a source of animal feeds for agriculture...

and other species of Spirodela

Spirodela

Spirodela is a genus of aquatic plant. It is one of several genera containing plants commonly called duckweed. Spirodela species are members of the Araceae under the APG II system. They were formerly members of the Lemnaceae....

. In 1999 D.H. Les and D.J. Crawford proposed segregating the species to a new genus Landoltia containing just the species L. punctata, on the basis of biochemical and DNA studies.

S. punctata originally was found in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and South Asia

South Asia

South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

, but today it can also be found in the Southern and Eastern United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.