Eutrochium fistulosum  (Eupatorium f., Eupatoriadelphus fistulosus) hollow-stemmed joe-pye weed Asteraceae EUFI; Bx, pb (DeCandido 2001); NY, iw; Q (DeCandido 2001); K, p; R, c, cs, gb, is, lp, w;

   

eutrochium-fistulosum-close-up-copyright-david-g-smith-delawarewildflowers-org

Eutrochium fistulosum.close-up.Copyright David G. Smith.delawarewildflowers.org

Eutrochium fistulosum is a perennial herb, much like E. purpureum but larger, to 3 m, stem purple, (usually not spotted), with a conspicuous waxy bloom (strongly glaucous), hollow between nodes. 

Leaves in whorls of 4-7, narrowly elliptic to lance-shaped, marginal teeth finer, blunter than those of E. purpureum, pointed at both ends, surface often puckered by impressed veins, veins pinnate. 

Flowers purple-pink, about 0.4 cm long, 5-8 per head, no rays; inflorescence dome-topped or pyramidal, 10-50 cm tall 10-30 cm wide, branches divergent; blooms July-Sept. 

Fruit dry, 1-seeded, 5-angled plumed achene about 0.4 cm long; winter flower stalks tipped by tiny white button-like receptacles. 

Wetland status: FACW. 

Frequency in NYC: Infrequent. 

Origin: Native. 

Habitat: Marsh edges, wet roadside ditches.