Ambrosia antemisiaefolia
is an annual herb originating in North America, growing wild in
various districts, and reportedly being a cause of pollenosis from
summer through autumn. Stems generally have vellus hairs and rise to
0.3-1m in height. Leaves are tender, opposite on lower parts,
alternate on upper legs, and bipinnately cut in deeply. Male flower
heads, 3-4mm in diameter, set themselves in slender racemes facing
downward, and female flower heads gather together at axils at the
bases of the inflorescences in a nearly unnoticeable way. Bloom
time: July-October. |