Japanese name: アメリカアゼナ Scientific name:Lindernia dubia
[Overview]
An annual 10–30 cm tall, found in damp places such as rice paddies.
The stem is hairless and branched.
The leaves are simple and opposite, ovate to oblong, about 1–3 cm long and 0.5–1.3 cm wide, with a slightly pointed or blunt tip.
The leaves have 3–5 parallel veins, are hairless on both surfaces, and usually have 2–3 pairs of low teeth on the margin.
The flowers are solitary in the leaf axils on the upper part of the stem, and the flower stalk is often as long as the leaf or shorter.
The flowers are very pale purple and two-lipped; the upper lip is shallowly 2-lobed and the lower lip is 3-lobed.
There are 4 stamens, but the lower 2 have no anthers.
The calyx is 5-lobed almost to the base, and the lobes are linear, 0.5 cm long, with pointed tips.
The fruit is an elliptic capsule of almost the same length as the calyx lobes.
