The Collaborative International Dictionary of English v.0.48:
Water agrimony \Wa"ter ag"ri*mo*ny\ (Bot.) A kind of bur marigold (Bidens tripartita) found in wet places in Europe. [1913 Webster]WordNet (r) 3.0 (2006):
Bidens tripartita n 1: bur marigold of temperate Eurasia [syn: European beggar- ticks, trifid beggar-ticks, trifid bur marigold, Bidens tripartita]