"Pygmy water-lily "

Description

Nymphaea tetragona is a species of flowering plant commonly called pigmy waterlily and small white water lily, belonging to the family Nymphaeaceae.In North America and Europe it native range is restricted to the boreal regions above 50° N latitude. Nymphaea tetragona is an aquatic perennial with floating leaves and white flowers growing from unbranched rhizomes. The leaves have entire margins and maybe tinted purple or sometimes mottled reddish brown or purple.The receptacle is four-angled.Plants produce a single floating flower that is 1.5 to 3 inches wide, with up to 15 petals; each flower has 30 to 45 yellow stamens.The sepals and out petals are produced in whorls of four, the sepals are green in color. The seeds are rounded in shape and 2-3 × 1.5-2 mm long, being 1.3-1.5 times as long as broad; the species has 112 pairs of chromosomes.Flowering occurs in summer and the flowers close at night. Nymphaea tetragona inhabits ponds, lakes, and quiet streams; and is native to: Alaska, Alberta, Altay, Amur, Assam, Bangladesh, Buryatiya, China North-Central, China South-Central, China Southeast, Chita, East European Russia, Finland, Hainan, Inner Mongolia, Irkutsk, Kamchatka, Kazakhstan, Khabarovsk, Korea, Krasnoyarsk, Kuril island., Magadan, Manchuria, Manitoba, Mongolia, Myanmar, North European Russian, Northwest European, Northwest Territories to British Columbia in Canada, Primorye, Sakhalin, Saskatchewan, Taiwan, Tibet, Tuva, Vietnam, Washington state in the USA, West Himalaya, West Siberia, Xinjiang, Yakutskiya, and the Yukon. It is listed as a threatened species in the US state of Minnesota, where it is found in slow moving streams often associated with beavers that provide suitable habitat by building dams. In Minnesota the plants are typically found in water that is 1 to 2 meters deep growing in association with Zizania aquatica, Sagittaria sp, Scirpus sp, and Typha sp; Nymphaea odorata var. tuberosa and Nuphar variegata (Yellow Pond-lily) are also commonly found in the same locations.