From The Collaborative International Dictionary of English v.0.48 :
Tradescantia \Trad`es*can"ti*a\, prop. n. (Bot.) A genus including spiderwort and Wandering Jew. [1913 Webster]From WordNet (r) 3.0 (2006) :
Tradescantia n 1: spiderworts [syn: Tradescantia, genus Tradescantia]