Scientific Name: Solidago giganteae

Common Name: giant goldenrod

Synonyms: Aster latissimifolius, Solidago pitcheri, Solidago serotina, Solidago serotinoides

Habit: Erect perennial weed that is often 1 to 2 m tall. Sparsely branched on the upper half of the plant only.

Leaves: Elliptic to lanceolate in shape 6 to 17 cm long and 1 to 4 cm wide. Leaves have short petioles and the younger leaves almost appear sessile. Older leaves will also senesce and eventually fall off. Hairs can be found along the midrib on the underside of the leaf.

Identifying Characteristics: This weed grows from underground rhizomes and slowly spreads. Stems are hairless and leaves are pubescent only on the underside. The inflorescence is only at the terminal and is almost panicle like. This species can be confused with <a href='../../weedimg/30'>Solidago altissima</a>, Canada goldenrod, but can be distinguished by its glabrous stem unlike S. altissima which has a densely pubescent stem.

Flower Seed Head: Panicle like clusters of 10 to 20 flowers that are yellow that may be green on the tips. Each individual flower is 2 to 3 mm across.

Seed Fruit: The fruit is an achene that is 1 to 1.5 mm long and has a papus on one end. The papus looks like fibers protruding from the end of the achene.

Where Found: Fallow fields, pastures, meadows, roadsides

  • Life cycle: perennial

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Asteraceae

  • Leaf arrangement: alternate

  • Leaf shape: lance; oval

  • Ochrea: Not Present

  • Leaf margin: serrated

  • Stem hairs: no hairs

  • Flower color: yellow

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: has hairs; no hairs

  • Flower diameter: pencil

  • Flower symmetry: radial symetery

  • Root structure: fibrous; taproot

  • Leaf stalk: shorter than leaf; none