The Collaborative International Dictionary of English v.0.48:
Sowbane \Sow"bane`\, n. (Bot.) The red goosefoot (Chenopodium rubrum), -- said to be fatal to swine. [1913 Webster]WordNet (r) 3.0 (2006):
Chenopodium rubrum n 1: common Eurasian weed; naturalized in United States [syn: red goosefoot, French spinach, Chenopodium rubrum]