The Collaborative International Dictionary of English v.0.48:
Nyctaginia \Nyctaginia\ prop. n. A genus consisting of only one species. Syn: genus Nyctaginia. [WordNet 1.5]WordNet (r) 3.0 (2006):
Nyctaginia n 1: a caryophyllaceous genus of the family Nyctaginaceae having only one species [syn: Nyctaginia, genus Nyctaginia]