Ruppiaceae

Ruppiaceae is a small family of aquatic flowering plants. The family contains only one genus, Ruppia, and is commonly known as the pondweeds or ditch-grasses. These plants are found in brackish and saltwater habitats worldwide, including salt marshes, estuaries, and alkaline lakes.

Ruppia species are submerged herbaceous plants with slender, creeping stems. Their leaves are typically thin and grass-like, often only a millimeter or two wide, and may be simple or finely divided. The flowers are inconspicuous, lacking petals and sepals, and are borne on short stalks. Reproduction can occur through sexual means, with pollination often facilitated by water currents, or vegetatively through rhizomes and fragmentation.

The family is characterized by its adaptation to saline environments, where few other vascular plants can survive. Ruppia plays a role in aquatic ecosystems by providing habitat and food for some aquatic animals. The taxonomic placement of Ruppiaceae has been debated, but it is generally placed within the order Alismatales.