Centipeda Lour.

Involucral bracts with scarious margins, acute, in 2 rows Centipeda
Inner bisexual florets 0.6–0.8 mm long
Cypselas less than 1 mm long; 0.4–0.5 mm wide; area between ribs concave; trichomes arranged in rows. Heads 2.5–5 mm diam, sessile; 9–11 bisexual florets per head. Leaves ± spathulate, 3–12 mm long. Cottony annual with stems to 15 mm long. Uncommon. Wet places. Clay soils Centipeda nidiformis
Cypselas 1.5–2.5 mm long; trichomes scattered. Heads 4–9 mm diam., sessile. 20–50 bisexual florets per head. Leaves sessile, stem-clasping, 10–12 mm long, 2–3 mm wide, with sinuate margins. Erect to decumbent aromatic perennial up to 20 cm high, glabrous to woolly. Widespread. Wet places. Fl. summer. Sneeze Weed Centipeda cunninghamii