| marsh elder | (n) any of various coarse shrubby plants of the genus Iva with small greenish flowers; common in moist areas (as coastal salt marshes) of eastern and central North America, Syn. iva |
| burweed marsh elder | (n) tall annual marsh elder common in moist rich soil in central North America that can cause contact dermatitis; produces much pollen that is a major cause of hay fever, Syn. Iva xanthifolia, false ragweed |