giant goldenrod
Family
AsteraceaeScientific Name
Solidago giganteaeSynonyms (former Scientific Names):
Solidago serotina
Solidago pitcheri
Solidago serotinoides
Aster latissimifolius
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 Solidago altissima, 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
Growth Habit
upright and nonwoody
Thorns or Spines
not present
Approximate Flower Diameter
pencil
Dominant Flower Color
yellow
Flower Symmetry
radial symmetery
Leaf Hairs
Varies:
has hairs,
no hairs
Leaf Shape
Varies:
lance,
oval
Leaf Arrangement
alternate
Leaf Margin
serrated
Leaf Structure
simple
Leaf Stalk
Varies:
none,
shorter than leaf
Stem Hairs
no hairs
Stem Cross Section
round or oval
Milky Sap
not present
Root Structure
Varies:
fibrous,
taproot
Life Cycle
perennial
Ochrea
not present
Plant Type
Herb