The Collaborative International Dictionary of English v.0.48:
Sharewort \Share"wort`\ (sh[^a]r"w[^u]rt`), n. (Bot.) A composite plant (Aster Tripolium) growing along the seacoast of Europe. [1913 Webster]WordNet (r) 3.0 (2006):
Aster tripolium n 1: a common European aster that grows in salt marshes [syn: sea aster, sea starwort, Aster tripolium]