Coarse Sumpweed - Iva xanthifolia
Other Names:
Cyclachaena xanthiifolia, Cyclachaena xanthifolia
Marsh elder Taprooted annual. Stems erect, unbranched below, 30–100 cm. Herbage strigose to canescent; stem villous above. Leaves long-petiolate; blades ovate to deltoid, cuneate to cordate, serrate, 5–20 cm long. Inflorescence of numerous, branched, axillary racemes. Involucres 2–3 mm high; phyllaries 5 to 8, obovate, mucronate, villous, glandular. Female flowers 5, obscure. Male flowers 5 to 10; corolla ca. 2 mm long. Achenes 2–3 mm long, glabrate (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).