An umbel-shaped flower cluster of Cynanchum viminale may be densely many-flowered when conditions allow. All-year-round flowering after rain may peak in summer. These flowers were seen in the Kammanassie during April.

The five-pointed star of ascending, convex sepals surround the white corolla and tiny central corona of each flower (Smith, et al, 2017; Vlok and Schutte-Vlok, 2015).