a naturalized annual herb of 10-30cm in height, originating in
Eurasia, inhabit roadsides or fields in coastal areas. Stems have
four ridges, with oval-shaped leaves, 1-2cm in length, 0.5-1.5cm in
width, branch well, and spread sideways. The leaves are of opposite
phyllotaxis, with no petioles and entire margins. Axils emerge
cymes, in which small tubular vermillion flowers cleft at the tips
in five blooms. Bloom time: March-May.