Guwahati: In a remarkable botanical breakthrough, scientists from the Botanical Survey of India (BSI) have discovered a new flowering plant species — Crassicaulis middletonii — in the evergreen forests of Arunachal Pradesh’s West Siang district.
The find marks the first-ever record of the genus Crassicaulis in India, extending its known range by more than 1,200 kilometres westward from China’s Yunnan province.
The discovery, published this week in the international journal Taiwania, was made by botanists Krishna Chowlu, Akshath Shenoy, and Althaf Ahamed Kabeer of BSI’s Arunachal Pradesh Regional Centre in Itanagar.
“This is a significant addition to India’s flora,” said co-author Akshath Shenoy, the corresponding author of the paper. “Crassicaulis middletonii not only represents a new species but also a new genus for India — a rare event in plant taxonomy.”
The newly described plant, belonging to the Gesneriaceae family (commonly known for ornamental species like African violets), grows up to 30 cm tall and thrives along stream banks near small waterfalls at about 800 metres elevation.
Its leaf base, white flowers tinged with pink, capsule shape, greenish ovary, and calyx distinguish it from its only known relative, Crassicaulis guiliangii, found in Yunnan.
The researchers named the species in honour of Dr. David J. Middleton, a leading taxonomist and former Head of Research at the Singapore Botanic Gardens, for his contributions to Asian plant science.
Field surveys revealed fewer than 50 individual plants in a single population near Pushi Doke village. The habitat — small forest streams surrounded by rice cultivation and grazing land — faces pollution, landslides, and flooding, putting the newly found species at high risk of extinction.
Given its extremely restricted range and anthropogenic pressures, Crassicaulis middletonii has been assessed as “Critically Endangered” under the IUCN Red List criteria.
“This discovery highlights both the botanical richness and the vulnerability of Arunachal Pradesh’s ecosystems,” said co-author Krishna Chowlu. “It underscores the urgent need for habitat protection and further exploration of understudied regions in the Eastern Himalayas.”
Until now, Crassicaulis was known only from China, where it was described just months ago. Its discovery in Arunachal Pradesh shows that the Himalayan biodiversity corridor continues to reveal new evolutionary links between India and Southeast Asia.
“This finds bridges a biogeographical gap,” Shenoy explained. “It suggests that many plant lineages thought to be confined to Southeast Asia may have undiscovered representatives in India’s northeastern forests.”
By uncovering Crassicaulis middletonii, scientists have once again demonstrated that the Eastern Himalayas — one of the world’s biodiversity hotspots — still hold secrets waiting to be revealed.