There is no Plathymenia foliolosa in POWO, only Plathymenia foliolosa var. paraguariensis Chodat & Hassl. (https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:201704-2) as a synonym of Plathymenia reticulata Benth. (https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:328385-2), and several other sources also include Plathymenia foliolosa as synonym of the latter.