Najas, the water-nymphs or naiads, is a genus of aquatic plants. It is cosmopolitan in distribution, first described for modern science by Linnaeus in 1753. Until 1997, it was rarely placed in the Hydrocharitaceae, and was often taken as constituting the family Najadaceae.
Najas minor, known as brittle naiad or brittle waternymph, is an annual aquatic plant, a submersed herb. It is native to Europe, Asia and North Africa from the Netherlands to Morocco east to Japan and the Philippines, including China, Siberia, Central Asia, Iran, Turkey, Ukraine, Germany, France Italy and a host of other countries. It is now introduced to North America and considered a weedy invasive species in the eastern half of the United States from Florida to Oklahoma to New Hampshire to Ontario to South Dakota. This plant prefers calm waters, such as ponds, reservoirs, and lakes, and is capable of growing in depths up to 4 meters.
Najas flexilis is an aquatic annual plant native to parts of North America and Europe. It is native to northern and central Europe from Norway to Ireland to Switzerland, and from there across Russia. It is also considered native throughout most of Canada, and the northern United States in disjunct populations in southern California, Arizona, Missouri, South Carolina and Utah. Its common names include slender naiad and nodding waternymph.
Najas guadalupensis is a species of aquatic plant known by the common names southern waternymph, guppy grass, najas grass, and common water nymph. It is native to the Americas, where it is widespread. It is considered native to Canada, and most of the contiguous United States, Mexico, Central America, the West Indies and South America. It has been introduced in Japan, Israel and Palestine.
Alisma triviale, the northern water plantain, is a perennial semi-aquatic or aquatic plant in the water-plantain family (Alismataceae).
Sagittaria cuneata is a species of flowering plant in the water plantain family known by the common name arumleaf arrowhead or duck potato. Like some other Sagittaria species, it may be called wapato. It is native to much of North America, including most of Canada as well as the western and northeastern United States.
Sagittaria longiloba is a species of flowering plant in the water plantain family known by the common name longbarb arrowhead and Gregg arrowhead. It is native to the south-central and southwestern United States plus Mexico, Venezuela and Nicaragua. It is also reportedly naturalized in the western Himalayas of India and Bhutan. It grows in slow-moving, stagnant, and ephemeral water bodies such as ponds and small streams, and sometimes disturbed and cultivated habitat such as rice fields and irrigation ditches.
Najas wrightiana is a species of aquatic plant in the Hydrocharitaceae family. It is referred to by the common name Wright's waternymph, and is found in lakes and streams. It is native to Mexico, Guatemala, Belize, Honduras, the Bahamas, Cuba, and Venezuela. It is also considered introduced and naturalized in southern Florida.
Najas ancistrocarpa is a species of aquatic plant in the Hydrocharitaceae family. It grows in fresh water ponds and is a native to Japan (Honshu) and to parts of China.
Sagittaria isoetiformis, common name quillwort arrowhead, is an aquatic plant species native to Cuba and to the southeastern United States.
Sagittaria cristata, the crested arrowhead, is a plant species native to Ontario and north-central United States. It grows in shallow water along the edges of lakes, streams and marshes.
Sagittaria teres, the quill-leaved arrowhead or slender arrowhead, is an aquatic plant species in the genus Sagittaria native to the northeastern United States: Rhode Island, Massachusetts, New Hampshire, New York and New Jersey.
Sagittaria brevirostra, common name Midwestern arrowhead or shortbeak arrowhead, is an aquatic plant species native to North America. It is common in wet places in an area stretching from Michigan and Ohio south to Alabama and west to North Dakota, Colorado and northern New Mexico, plus isolated populations in Maryland, New Brunswick, Virginia, Saskatchewan and California.
Sagittaria filiformis, the threadleaf arrowhead, is an aquatic plant species native to the eastern United States, from Maine south to Florida and Alabama. it occurs in flowing streams in the northern part of its range, but more stagnant waters such as marshes and swamps in the South.
Sagittaria engelmanniana is an aquatic plant species native to eastern North America. It has been reported from every state bordering on the Gulf of Mexico or on the Atlantic Ocean from Mississippi to Massachusetts, plus Vermont and Ontario.
Sagittaria graminea, the grassy arrowhead or grass-leaved arrowhead, is an aquatic plant species native to eastern North America.
Sagittaria guayanensis, the Guyanese arrowhead, is an aquatic plant species. It is predominantly tropical, native to Mexico, Central America, the West Indies, and much of South America, as well as West Africa, south and southeast Asia, plus Sudan and Madagascar. It was unknown in the United States until a few populations were reported from Louisiana in 1969.
Liparis liliifolia, known as the brown widelip orchid, lily-leaved twayblade, large twayblade, and mauve sleekwort, is a species of orchid native to eastern Canada and the eastern United States. It can be found in a variety of habitats, such as forests, shrublands, thickets, woodlands, and mountains. The orchid is considered globally secure, but it is considered rare or endangered in many northeastern states.
Limnobium, common names spongeplant and American frogbit, is a group of aquatic plants in the Hydrocharitaceae described as a genus in 1814. It is widespread in freshwater environments in Latin America, the West Indies, and the United States.
Nymphaea tetragona is an aquatic perennial, species of flowering plant commonly called pygmy waterlily and small white water lily, belonging to the family Nymphaeaceae.
