Shaluk or Blue water lily (Nymphaea nouchali, family: Nymphaceae) is an aquatic plant grows from underwater soil. The plant is found in ponds, canals, beels and jheels everywhere in Bangladesh along with Water lily, Keshordam, Water spinach, Bladderwort and other aquatic plants.
Leaves are shiny green, purplish or reddish beneath, round or ovate, irregularly serrated, 15-32 cm long and 10-25 cm wide, floating on water. The length of petiole and pedicel increases with the rise of water level.
Flower is purplish and slightly scented. Petals 10-30, oblong to oblong-lanceolate, acute, arranged in three layers. Stamens numerous, 10-50, yellow in color. Petiole is 20-150 cm long. Sepals usually green, sometimes dull red, often marked with darker dots and lines. The flower is little bit smaller than Shapla, Water lily. Flower blooms at night. It remains open till noon. Flowering occurs in the rainy season to late autumn (July to November).
Fruit a spongy berry, 4.5 in diameter, ripening under water enclosed by persistent sepals. The propagation of the plant is caused by seeds and by bulb. It is also found in East Africa and South and Southeast Asia. As an ornamental plant it is planted in the water tanks and lakes in parks and gardens in Bangladesh. The Blue water lily is the national flower of Sri Lanka.
Other Bangla names: Kumud, Shundi, Nilkomol, Nil shapla, Nil poddo, Nil kombol.