A vertical world of forests
The highlands around Putao in northern Myanmar represent a unique biological crossroads. This area is where the eastern edge of the Himalayas converges with the mountains of south-central China and the tropical flora of Indochina. The result is a region of extreme altitudinal range and biodiversity, contained largely within Hkakabo Razi National Park, which covers 3,810 square kilometers.
The landscape is a series of vertically stacked ecosystems. Subtropical evergreen forests dominate the lower elevations, transitioning to temperate evergreen and mixed deciduous forests between 2,000 and 3,000 meters. Further up, these give way to evergreen coniferous and subalpine snow forests, which finally yield to alpine scrub and meadows above 3,352 meters. This rapid change in vegetation creates distinct biological communities in close proximity. The alpine zone, which begins around 4,000 meters, is considered a separate floral region with a different origin from the forests below it. This intense layering of habitats, driven by elevation, is the main reason for the area's high concentration of plant species.
A hotspot for discovery
The Putao highlands are part of the Himalaya and Indo-Burma biodiversity hotspots, global important areas for conservation. The region's complex geography and historical isolation have made it a factory for speciation, and modern botanical surveys still uncover species new to science. Since 2001, researchers have added more than 10 new species and 40 new records of Orchidaceae to the flora of Myanmar, many from this region.
Specific discoveries show the area's unique character. Odontochilus putaoensis, a terrestrial orchid with a bright yellow lip, was found growing in montane forest between 1,500 and 2,000 meters. Another new orchid, Coelogyne magnifica, grows on moss-covered trees at elevations of 2,400 to 2,500 meters. Other finds include Bulbophyllum putaoensis from the Hponkanrazi Wildlife Sanctuary and Colocasia kachinensis, a new species of Araceae found in the mountain rainforest understory. In 2025, botanists formally described Mappianthus kachinensis, a woody climber, showing that many species in the region remain undocumented. This constant rate of discovery confirms the Putao highlands as one of the important centers for plant diversity in Asia.