Nymphaea nouchali Burm.f.

General description

Nymphaea nouchali is an aquatic plant whose tuberous rhizome is rooted in the soil and the leaves are under the surface of water or floating. The leaves are carried by a petiole of variable length depending on the height of the water. The leaf blade, variable in size, is circular with sinuous margin, with a deep basal sinus, smooth, glabrous, and yellowish green on the upper surface, bronze-green on the lower surface. Solitary terminal flower above the water surface, 5 to 12 cm in diameter, with 4 reddish sepals and numerous lanceolate petals with many shades of blue. Many bright yellow stamens. Ovary is yellow with numerous loculus.
 
General habit

Aquatic plant whose tuberous stem is rooted in the soil and the leaves floating on the water surface at the end of long petioles. It can be very variable in size, depending on the depth of water level and fertility of the medium.
 
Underground system

Tuberous rhizomes, robust and spongy, short, erect with thick, more or less branched, roots. It has circular scars embossed all along the leaf petioles and floral stalks.
 
Stem

There is no individualized stem, leaves and flowers emerge from the rhizome.
 
 
Leaf

Leaves simple alternate, stipulate. The petiole of variable length (0.2 to 1.9 m) depending on the depth of the water, is cylindrical, purple at the base and becoming bronze green in the upper portion (near the surface). It is hollow, with aeriferous canals. The leaf blade is more or less circular to elliptical, peltate with deep, asymmetrical basal sinus and rounded apex. It is very variable in size, can measure 20 to 40 cm in diameter. The leaf blade is inserted at the top of the petiole, a few millimeters from the base of the sinus. The margin is deeply and irregularly sinuous and curved upwards. The upper side is green to yellowish green, smooth and shiny, covered with a very hydrophobic waxy cuticle. The underside is bronze-green, smooth, hydrophilic and marked with 7-15 palmate radiating, slightly prominent veins and a network of secondary anastomosing veins. Both sides are hairless. Some remain under the surface of the water, others spread on the surface. They have a short life span and are replaced regularly throughout the growing season.
 
Inflorescence

Terminal solitary flower at the end of a long erect, cylindrical, smooth stalk, 1 to 2 cm in diameter.
 
Flower

The flower blooms on the surface or up to 30 cm above the water surface. It measures 5 to 12 cm in diameter. The calyx consists of four reddish lanceolate sepals. The corolla consists of numerous lanceolate petals showing shades of blue more or less dark from the top to the bottom. The numerous stamens (20-60), are bright yellow. The multilocular ovary is yellow.
 
Fruit

Spongy fleshy fruit, 1.5 to 4.5 cm in diameter, surrounded by accrescent sepals that ripens under water. It contains many small seeds embedded in a spongy substance.
 
Seed

Seed ovoid,  2 mm long and 1 mm wide, finely reticulated.