Nymphaea nouchali, often known by its synonym Nymphaea stellata, or by common names blue lotus, star lotus, red water lily, dwarf aquarium lily, blue water lily, blue star water lily or manel flower, is a water lily of genus Nymphaea. It is native to southern and eastern parts of Asia, and is the national flower of Bangladesh and Sri Lanka. In Sanskrit it is called utpala. This species is usually considered to include the blue Egyptian lotus N. nouchali var. caerulea. In the past, taxonomic confusion has occurred, with the name Nymphaea nouchali incorrectly applied to Nymphaea pubescens.
N. nouchali is a day-blooming non-viviparous plant with submerged roots and stems. Part of the leaves are submerged, while others rise slightly above the surface. The leaves are round and green on top; they usually have a darker underside. The floating leaves have undulating edges that give them a crenellated appearance. Their size is about 20–23 cm (8" to 9") and their spread is up to 1.5 metres (5') from the rhizome.
This water lily has a beautiful flower which is usually white or blue in color. Its variants occur in white, blue,violet,purple,pink & cream/yellowish white colours.The flower has four or five sepals and 13-15 petals that have an angular appearance, making the flower look star-shaped from above. The cup-like calyx has a diameter of 4–15 cm (2" to 6").
The leaves of the lily can be affected by a water-born fungi, Doassansiopsis nymphaea.
This aquatic plant is native in a broad region from Afghanistan, the Indian subcontinent, to Taiwan, southeast Asia and Australia. It has been long valued as a garden flower in Thailand and Myanmar to decorate ponds and gardens. In its natural state, N. nouchali is found in static or slow-flowing aquatic habitats of low to moderate depth.