Water lilies (Nymphaea)(睡蓮, 子午蓮, 瑞蓮 or 小蓮花) are aquatic herbs that grow from rhizomes (modified roots) in soil under bodies of water, with leaves and flowers floating on the surface. The plant grow in the temperate and tropical climates round the world.
Some species have flowers open in the morning and close in the evening and at night, its Chinese name is sleeping water-lilies 睡蓮. Not all water lilies are day-blooming, some varieties are night-blooming.
Water lilies are different from the lotus (Nelumbo)(蓮, 蓮花 or commonly known as 荷花). They belong to different Order, Family and Genus.
In the Chinese prose Ài Lián Shuō (愛蓮說) by Zhou Dunyi (周敦頤) (1017 – 1073): Out of the turbid waters, it stands pure and unsullied (蓮之出淤泥而不染), most scholars believe that Zhou was describing the lotus flower rather than the water lilies.
The difference between water lilies and the lotus
First the leaves of the water lilies float on the surface of the water, whereas the leaves of the lotus are raised above the water surface.

Secondly, the leaves of water lilies are quite flat whereas the leaves of the lotus has an inverted umbrella shape.

Thirdly, the leaves of water lilies have a radial notch or groove whereas the leaves of the lotus is round and complete.


Chinese painting of waterlilies
There are much fewer water lilies paintings than lotus paintings. Some contemporary artists eg Bao Shao-you (鮑少游). Yú Zhìzhēn (俞致貞) and Chao Sung-ch’Uan (趙松泉) did some water lilies paintings. Perhaps the popularity and the beauty of lotus overshadows that of water lilies.




Claude Monet and water lilies
Claude Monet (1840 – 1926) a founder of French Impressionist painting is famous for his water lilies paintings.

Early Water lilies of Monet




Late Waterlilies of Monet




Japanese bridge and pool of water lilies


Acknowledgements :
I would like to express my sincere gratitude to Ms Joanne Lam for her consistent support.
Bibliography :
https://en.wikipedia.org/wiki/Nymphaeaceae
https://zh.wikipedia.org/wiki/%E9%AE%91%E5%B0%91%E6%B8%B8
http://baike.baidu.com/view/225402.htm
https://en.wikipedia.org/wiki/Claude_Monet
https://en.wikipedia.org/wiki/Water_Lilies_(Monet_series) (highly recommended)
http://www.claudemonetgallery.org/
https://en.wikipedia.org/wiki/Mus%C3%A9e_de_l%27Orangerie
http://www.ngansiumui.com/about/vanessa-lam_essay.html
Chao Sung-ch’Uan (1981) Chao Sung Ch’uan Paintings, published by Ho Kung-shang, Art Book Co., Ltd, Taiwan
Gordon, R and A Forge A,(1983) Monet, Abradale Press ISBN 0-8109-8091-6
Monet’s Years at Giverny: Beyond Impressionism (1978) The Metropolitan Museum of Art. Abrama ISBN 0-8109-2183-9