Oxypetalum saxatile Oxypetalum hookeri Turrigera lessonii Cynanchum birostratum Cynanchum cheiranthoides Gothofreda birostrata Gothofreda obliquifolia Oxypetalum confertiflorum Tweedia brevipes Tweedia confertiflora Tweedia obliquifolia Gonolobus obliquifolius Gonolobus voquicilla Gothofreda brevipes Gothofreda confertiflora Oxypetalum brevipes Oxypetalum angustifolium Tweedia hookeri
World Flora Online, http://www.worldfloraonline.org/, accessed June 20, 2024