Japanese name: オオキンケイギク（大金鶏菊） Scientific name:Coreopsis lanceolata
[Overview]
A perennial 30–70 cm tall.
It is found along roadsides, on riverbanks and in vacant lots, and often forms large colonies.
There are basal leaves and stem leaves; the basal leaves consist of 3–5 leaflets, with narrow spatulate lobes that are entire.
The basal leaves have long leaf stalks.
The leaves on the stem are alternate, and those in the upper part are not divided.
Both sides of the leaves are covered with coarse hairs.
Flower heads about 5–7 cm across are borne at the stem tip.
The ray florets are orange-yellow with irregular notches at the tip.
The tubular florets are also orange-yellow.
Some plants have reddish brown bases on the ray florets, and some have double flowers.
The fruit is a flat achene with a thin, translucent wing along the edge.
[History]
It was introduced as an ornamental in the mid-Meiji period.
[Notes]
It is designated a "Specified Invasive Alien Species" under the Invasive Alien Species Act.
