Japanese name: アメリカキカシグサ Scientific name:Rotala ramosior
[Overview]
An annual 10–40 cm tall, found in rice paddies and damp places.
The stem is erect, with ascending branches.
The leaves are simple and cross-opposite, linear to lanceolate, 1–5 cm long.
The leaf margin is entire.
There is no petiole.
The flowers are solitary in the leaf axils and are white to pink with 4 petals, but the petals fall early.
The calyx is 4-lobed, and triangular appendages of the same size as the sepals are present in the positions alternating with the sepals.
There are 2 bracts at the base of the calyx.
The fruit is a globose to urn-shaped capsule.
[History]
It was collected and reported in Yokohama in 1993, and naturalization has since been confirmed in various places.
