Periyar Tiger Reserve is one of the richest biodiversity pockets in the Western Ghats. Of nearly 4500 known flowering plants in the region, as many as 2000 species have been reported from Periyar itself. One fourth of these species are endemic to Southern Western Ghats.

Smithia racemosa is an endemic shrub that thrives in strong sunlight so is found growing in open areas along forest edges and mountain slopes.