The water lily gets its genus name from the Greek nymphae, meaning “water nymph”1 or “water goddess”2. Venusta means “charming, handsome”, from Latin venustus, “charming, elegant”3.
1 :Growing Herbs with Margaret Roberts; First published 1985
2 nymphae, on The Botanary at Dave’s Garden
3 venusta on California Plant Names: Latin and Greek Meanings and Derivations