Drosera arachnoides is a carnivorous plant in the family Droseraceae. It is endemic to Madagascar. Description. "Drosera arachnoides" is similar to the closely related "Drosera humbertii". Its leaves are 22-40 millimeters long, and a mature plant can have a stem that is 25-45 millimeters tall. Distribution. "Drosera arachnoides" is native to the Fianarantsoa and Toamasina provinces of Madagascar.