The park is floristically rich due to its characteristic climatic condition. 803 taxa (76 Pteridophytes and 727 Angiosperms) were collected and described from the park. They belong to 332 genera representing 134 families. Dicotyledons dominated with 505 species belonging to 240 genera and 90 families. Monocotyledons were represented by 222 species under 92 genera and 16 families. 10 dominant families with respect to species richness are Poaceae (105 species and 39 genera), Orchidaceae (66 species and 23 genera), Asteraceae (48 species and 24 genera), Rubiaceae (43 species and 17 genera), Balsaminaceae (39 species and 1 genus), Acanthaceae (31 species and 7 genera), Papilionaceae (26 species and 12 genera), Lauraceae (32 species and 6 genera), Melastomataceae (18 species and 4 genera), Lamiceae (17 species and 7 genera). Fern groups here are endemic and comprises of 76 species under 35 genera and 28 families. Nearly 190 species are Western Ghat endemics and 89 among these are placed under various threat categories. During the study, 36 species of Impatiens were collected in and around the park of which 18 are locally endemic and not seen anywhere in the Western Ghats.
They harbour 15 species of Arisaema which are confined to this area alone and 2 species of Ophiorrhiza which was recollected after 68 year. Other endemics of this region are Anaphalis barnesii, Begonia aliciae, Didymocarpus mcrostachya, Habenaria flabelliformis etc. (Floristic studies on Eravikulam National Park Biju S.D. TBGRI, Palode 2004)