Five new polycarpaea or spiked rock-grass (acharam kolli) species have been discovered from Central Kerala regions. Till now, only ten species of spiked rock-grass have been known, and seven are endemic to the Western Ghats.

One of the five newly-discovered species, Polycarpaea kurialacherryana, has been named after Mar Thomas Kurialacherry (1873–1925), the first Bishop of the Archdiocese of Changanassery and the founder of St Berchmans College, Changanassery. The primary habitat of Polycarpaea kurialacherryana is the dry coarse soil area scattered in the rock crevices on the outskirts near Kanthalloor of Idukki district. Polycarpaea kurialacherryana sprouts after the beginning of monsoon. It has yellow-coloured flowers.

Yet another species was discovered from Kanthalloor: Polycarpaea kanthalloorensis. It has yellow-coloured sepals and ovate or egg-shaped dark brown-pinkish petals. It prefers dry, gritty soil found in rock fissures on the outskirts of Kanthalloor in Idukki district.

The dark green plant with yellow spots discovered from Cherthala has been named Polycarpaea johnii. It prefers sandy soil with coarse texture having low moisture retention. Its name comes from Rev Prof MC John, former Principal and Head of the Department of Botany, CMS College Kottayam, and the dedication recognises John's lifetime contributions to classical plant taxonomy.

Polycarpaea sureshii, found from Palakkad, is named in honour of Dr V Suresh, Professor, Department of Botany, Government Victoria College, Palakkad, in recognition of his contributions to the field of plant taxonomy and his efforts to conserve the floristic diversity of the Palakkad Gap region. The predominant habitat of Polycarpaea sureshii is the dry loose soil dispersed on the rock surfaces from Kollengode in Palakkad district. Its flowers are coffee-coloured with red spots.

Polycarpaea marayoorensis was discovered in the rock crevices on the outskirts of Marayoor in Idukki district. It appears after the onset of monsoon. The epithet 'marayoorensis' refers to the locality of the type specimen.

It was the close scrutiny of the structure of the flower, its seed and pollen grain that led to the discoveries of the five new species. The investigation had spread over three years. The team behind the discovery are: Salvy Thomas and Sindhu Arya of St Berchman's College Botany Department; Rogimon P Thomas of C M S College, Kottayam; and independent researcher Manuel Thomas.

The findings were first published in the peer-reviewed scientific journal Phytotaxa.