I. Helenium: stems stout, erect, scarcely branched, 3-5 feet high; leaves often a foot long, oblong, narrowed into a stalk; the upper ones clasping the stem, downy beneath; flower-heads very large, the ray-florets numerous, linear, yellow; involucral bracts broadly ovate, softly hairy. - Elecampane. - Moist pastures. Fl. July, August.
I. Conyza: biennial; stems hard, erect, 2-3 feet high, roughly downy; leaves ovate-lanceolate, downy, the upper sessile; flower-heads numerous, in a terminal corymb; the ray-florets numerous but very small. - Ploughman's Spikenard. - Hedges, banks, and roadsides. El. July to September.