The large, elegant fragrant white flowers are held well above the water at the tip of a sturdy green stalk and appear almost constantly from spring until the end of summer. They are bisexual, star-like and regular with 4 sepals, green on the outside with many white petals. This is one of the most generously blooming water lilies, and frequently has as many as a half a dozen flowers open on a single day.
The thick rhizomes are un-branched, erect, and ovoid without stolons. The leaf blades are green with smooth purple edges, often spotted and the bottom leaves are reddish. They are ovate to nearly round, about 15-45 cm in diameter, with dentate margins and a radiated venation centrally prominent, without web-like pattern, and a glabrous surface.
The flowers are emersed, 7-18 cm in diameter, opening and closing diurnally, with only the sepals and outermost petals in a distinct whorl of 4. The sepals are green, flecked with short dark streaks and faintly veined. There are between 12-21 pointy white petals per flower, with 50-190 yellow stamens positioned around a 3 mm central yellow disk. The seeds are nearly globose to ellipsoid, with longitudinal rows of hair-like papillae. The Nymphaea Ampla blooms all year round in hot climate.
Hardiness zones: 4-11(-32c/-25f, 4c/40f)