Helianthus decapetalus L.

• Authority

  Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

• Family

  Asteraceae

• Scientific Name

  Helianthus decapetalus L.

• Description

  Species Description - Perennial from slender rhizomes; stem 0.5–1.5(–2) m, glabrous below the short-hairy infl; lvs thin, pale beneath, moderately scabrous to subglabrous, broadly lanceolate to ovate, 8–20 × 3–8 cm, long-acuminate, serrate (generally sharply so), ± abruptly contracted near the base and decurrent onto the 1.5–6 cm petiole; upper lvs usually alternate; disk yellow, 1–2 cm wide; invol bracts very loose, thin, green, conspicuously ciliate, occasionally hispidulous on the back, attenuate- acuminate, at least some of them usually conspicuously surpassing the disk; rays 8–15, 1.5–3.5 cm; 2n=34, 68. Woods and along streams; Me. and Que. to Wis. and Io., s. to Ga. and Mo. Aug.–Oct. (H. trachelifolius)

• Common Names

  forest-sunflower