Nymphaea 'Sulphurea Okechobee' is a hardy waterlily with large lemon yellow flowers that have long narrow petals. The leaves are mottled with purple. Waterlilies are rhizomatous aquatic plants with about 50 species Waterlilies are rhizomatous aquatic plants with about 50 species occurring in the wild, mostly found in the tropics of the Northern Hemisphere.  They are characterized by round notched leaves that lie flat on the water, and flowers with numerous petals produced at the end of a long lax stem and floating just above the water surface. In the center of each flower is a cluster of showy stamens. Waterlilies have been cultivated since at least 2,000 B.C. and are divided into hardy hybrids, tropical day-blooming and tropical night-blooming. Waterlilies need full sun to flower and need to be anchored in mud as they are not free-floating.