Asteraceae
Daisy Family
Ambrosia psilostachya DC.
- Stem: perennial; 1 1/2’ tall; branching; hairy.
- Leaves: alternate; basal leaves deeply pinnately lobed; 3” by 1”; hairy.
- Inflorescence: at the tips of branches; elongated heads on stalks 2” long; male heads above, a few female heads at the base.
- Heads: fillaries 1/4” long in female heads obscuring flowers; flowering begins in early August and continues until mid-September.
- Fruits: top-shaped “seeds” (fruits) about 1/8” long with a central point at one end surrounded by several other points; fruiting begins in mid-September.
- Habitat: on dry and sandy prairies.
- Bibliography from Biodiversity Heritage Library
- Vascular Plants of Iowa
