GUWAHATI
A new study has flagged the threat to native biodiversity from a botanical Brazilian beauty.
The Ruellia elegans derives its name from its pleasing appearance or elegance but its presence in eastern Assam’s Digboi could be unpleasant for the local flora, a study by botanist Mamita Kalita said.
Digboi, where Asia’s first oil well was drilled in 1866, is about 490 km east of Guwahati.
Ms. Kalita’s paper, published in the Journal of Threatened Taxa, said Ruellia elegans is native to Brazil, where its conservation status has reportedly not been assessed. “The impact of this invasive species should be monitored to take appropriate measures to control its spread threatening the native biodiversity,” the study warned.
Ruellia elegans, predominantly thriving in wet tropical biome, is commonly known as the Brazilian petunia, Christmas pride, elegant Ruellia, red Ruellia, and wild petunia. It is one of four invasive species of the Acanthoideae sub-family in India, the others being Ruellia ciliatiflora, Ruellia simplex, and Ruellia tuberosa.
Scientists consider invasive plant species as a problem because they can rapidly spread and outcompete native plants for resources like sunlight, water, and nutrients. They disrupt ecosystems by altering biodiversity, impacting wildlife habitats, and potentially causing the decline or extinction of native species, often leading to significant economic and environmental damage.
India, though, has six native species of Ruellia — beddomei, ciliata, malabarica, patula, sibua, and sivarajanii.
The Brazilian flowering plant was introduced in the Andaman Islands, apart from Jamaica and Puerto Rico. Ms. Kalita said the species’ distribution extended due to human activities.
She said eight to 10 individuals of Ruellia elegans, each differing in their reproductive growth, were seen at the Digboi site. “Its occurrence has been documented as a new distribution record for the flora of Assam and the rest of northeastern India,” she said.
Beyond the Andaman Islands, the invasive plant was recorded from Odisha almost a decade ago.
