Ruppia maritima


Ruppia maritima is a species of aquatic plant known by the common names beaked tasselweed, widgeon grass, ditch-grass and tassel pondweed. Despite its scientific name, it is not a marine plant; is perhaps best described as a salt-tolerant freshwater species. The generic name Ruppia was dedicated by Linnaeus to the German botanist Heinrich Bernhard Ruppius and the specific name translates to "of the sea".

Distribution

It can be found throughout the world, most often in coastal areas, where it grows in brackish water bodies, such as marshes. It is a dominant plant in a great many shoreline regions. It does not grow well in turbid water or low-oxygen substrates.

Description

Ruppia maritima is a thread-thin, grasslike annual or perennial herb which grows from a rhizome anchored shallowly in the wet substrate. It produces a long, narrow, straight or loosely coiled inflorescence tipped with two tiny flowers. The plant often self-pollinates, but the flowers also release pollen that reaches other plants as it floats away on bubbles.
The fruits are drupelets. They are dispersed in the water and inside the guts of fish and waterbirds that eat them. The plant also reproduces vegetatively by sprouting from its rhizome to form colonies.

Taxonomy and nomenclature

On the basis of molecular phylogenetic analyses, a species complex, named R. maritima complex, had been discerned, which was then extended to include eight lineages, or nine lineages.
A lectotype for R. cirrhosa is designated and the name is shown to be a homotypic synonym of R. maritima.

Wetlands and wildlife

This plant is an important part of the diet of many species of waterfowl. In many areas, wetlands restoration begins with the recovery and protection of this plant.