Botanical name: Spermacoce articularis Family: Rubiaceae (Coffee family)
Synonyms: Spermacoce scabra, Borreria articularis, Spermacoce flexuosa
Jointed Buttonweed is an annual herb, growing to 60 cm tall. The stems have few 4-angled branches near the base. Leaves are obovate to oblong-lanceolate, 1-5 cm long, 4-20 mm wide. The leaves are covered with fine hair. Flowers occur in groups of few, and are stalkless. The flower-tube is narrow, white in color, and 3 mm long. The 4 oblong-ovate petals are tinged pale purple, and covered with fine hair at the back. The filaments of the stamens protrude out of the flowers. The fruit is spherical-ellipsoid, 3 mm across. The plant is found in open spaces at low elevations.
The flower labeled Jointed Buttonweed is ...