Eupatorium altissimum is a perennial herb 80 cm to 2 m tall, stems solitary or paired, usually finely whitish hairy above, very leafy.
Leaves opposite, stalkless, or almost so, blade 5-12 cm long, 0.8-3 cm wide, narrowly elliptic, pointed at both ends, strongly 3-veined from base, margin toothed above middle.
Flowers white, 5 per head, no rays, bracteate base 0.5-0.7 cm long, finely hairy, bracts overlapping, blunt-tipped; blooms Aug-Oct.
Fruit a 5-angled plumed seed (achene).
Wetland status: UPL.
Frequency in NYC: Very infrequent.
Origin: Native to N. J., south, and west.
Habitat: Dry, open woods.