Periyar is rich in medicinal plants. More than 350 species
have been recognised as medicinally important. Majority of
the medicinal plants are trees followed by herbs and shrubs.
Among the families with species of medicinal importance, Fabaceae
comes first followed by Euphorbiaceae. The evergreen forests
support the majority of the medicinal plants followed by moist
deciduous forests and southern hilltop tropical evergreen
The common species are Glory Lily, (Gloriosa superba), Kino
Tree (Pterocarpus marsupium), Gymnema sylvestre, Hemidesmus
indicus etc. Begonia albo-coccinea is categorisd as vulnerable.