Photographer: Kenneth J. Sytsma
Helianthus giganteus L.
giant sunflower, swamp sunflower, tall sunflower
Helianthus: derived from two Greek words helios, "sun," and anthos, "flower," in reference to the sunflower's supposed tendency to always turn toward the sun
giganteus: very large, from Giganteus "of or belonging to the giants"
|Plant: ||erect, perennial, 3'-10' tall forb; stems usually with spreading hairs but sometimes hairless, often purplish|
|Flower: ||head 1 3/4"- 3 1/4" wide with 10-20 yellow rays, yellow disks, hairy bracts (phyllaries) long and loose; inflorescence in loose clusters of several to many heads on stalks less than 4" long; blooms July-Oct.|
|Leaf:||opposite on the lower stem, upper alternate, flat, narrow, at least 3 times as long as wide, upper surface rough, lower with long hairs|
|Habitat: ||moist; forests, swamps|
|Notes: ||very similar to H. grosseserratus except for longer hairs on underside of leaf, and rougher upper side.|