The plants in the picture have leaves that open during the day and close at night. What kind of plant is this?

Alias: Pearl grass, night grass (Sichuan Snow Mountain), Alpine ginseng (Chaoshan), Alpine ginseng, Alpine ginseng (Chaoan, Chaozhou), licorice (Puning, Chenghai), litsea grass (Jieyang, Puning), Hedao grass, Wushi River (Jieyang), Tian Yougan, Ching Tien, etc. Concave-bellied pearls or Tadou pearls (Huilai). Bird wheat (South Australia, Raoping, Chenghai), Bi Liangcao (sound, Anhui).

Morphological characteristics:

Annual herbs, 20~50 cm tall, with rhizomes. The stems are erect and much branched. Leaves small, alternate, arranged on both sides of branches, like pinnately compound leaves; Leaf blade oblong, apex acute or obtuse, base rounded, entire, petiole extremely short, or subsessile. In summer and autumn, reddish-brown flowers bloom in the axils of leaves, and reddish-brown small oblate fruits, about the size of matchsticks, are arranged under the leaves, hence the name.

Growing environment: Born in wet places or roadside gardens.