Photographer: Kenneth J. Sytsma
Ambrosia psilostachya DC.
perennial ragweed, western ragweed
Ambrosia: Greek for "food of the gods"
psilostachya: derived from the Greek psilos, "bare," and stachys, "a spike," hence a "bare spike"
|Plant: ||erect, perennial, 12"-40" tall forb with upper branches; creeping, fibrous roots|
|Flower: ||inflorescence of many, small, green, bead-like heads on 6" spikes; blooms Aug.-Sept.|
|Fruit:||seeds not on fluffy pappus|
|Leaf:||usually once pinnately-divided, lower leaves opposite, upper leaves alternate|
|Habitat: ||dry; prairies, disturbed sites; in sandy soil|