Ageratina altissima,
a
0.3-1.3m tall perennial herb originating in North America, is
distributed in various places in this country. Stems erect and
branch well on upper parts, with short hairs. Leaves with long
petioles, 2-5cm long, are of opposite phyllotaxis, 7-15cm long,
4-9cm wide, ovate-shaped, with coarse serrations on margins. The
upper part's stems set many white flowers in a corymbs way. Flower
heads comprise disk florets only. Bloom time: September-October. |