Common name: Water willow. Tamil Name: Kotakaalai.
Water willow is found in swampy wet stretches of Western Ghats, it is a gregarious herb that grows to around 10 cm in height. Often found crowded together in small patches in shaded areas. This plant is native to the Indian subcontinent. The simple leaves are arranged in an opposite manner. The leaves are ovate and measure around 2 cm in length. The inflorescence is in the form of a terminal dense spike of overlapping bracts. The sessile bi-lipped bisexual flower is pink. Rostellularia genus belongs to the Acanthaceae family and consists of about around 25 species. They are mostly prostrate/ascending herbs with angular stem with leaf bearing large curved cystoliths. Water willow besides being a source of nectar for insects is also the larval host plant for Lemon pansy and Blue Pansy butterflies.
