Guwahati: Botanists have recorded a rare flowering plant species in Assam for the first time, marking its confirmed entry into mainland India and expanding the known range of the species within the country.
Researchers discovered Heliotropium ovatum, a climbing shrub belonging to the Heliotropiaceae family, during a field survey in Assam’s Dima Hasao district in November 2024. The finding has now been published in the journal National Academy Science Letters.
The species was previously known in India only from the Andaman and Nicobar Islands, while earlier reports from Arunachal Pradesh remained unverified and were later excluded during taxonomic revisions. Outside India, the species has been reported from Myanmar and Thailand.
The study was carried out by Selim Mehmud of University of Science and Technology, Meghalaya and Kangkan Kumar Das and Debjyoti Bhattacharyya of Assam University, Silchar.
According to the researchers, a review of records from the Botanical Survey of India digital herbarium and major herbaria in the Northeast and Kolkata found no authenticated specimen of the plant from mainland India before this discovery.
“This collection represents the first confirmed record of H. ovatum for mainland India from Assam,” the paper noted.
The plant was found in the Jatinga Hills area of Dima Hasao district, growing among large rocks near a stream under direct sunlight. Researchers observed only five to six mature individuals at the site.
Scientists described the species as a climbing shrub reaching nearly two metres in height, bearing greenish-white flowers arranged in rows along branched inflorescences. The flowering season was recorded between November and December.
Apart from documenting its presence in mainland India, the researchers also identified a previously unreported morphological feature in the species.
The discovery is considered significant because Northeast India remains one of the least explored regions for plant diversity despite being part of the Indo-Burma biodiversity hotspot.
Researchers said findings like these demonstrate the ecological importance of hill ecosystems such as Dima Hasao, which continue to yield rare and poorly documented species during field surveys.
The paper also noted that the conservation status of the species has not yet been formally evaluated under guidelines of the International Union for Conservation of Nature.
Also Read: Explained: Why is a medicinal plant being smuggled across the Mizoram border?
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