The report from the World Wildlife Fund (PDF) highlights the "vast botanical world" hidden beneath the Himalayas' mountainous and tropical veneer.
Discoveries over those six years range from "families of flowering plants, aromatic plants celery, carrot or parsley family, cashew family, ferns, daisy or sunflower family, sedges, spurge, pea or bean family, shrubs, orchids, poppies and pines, bananas, nettles and heather, herbs and rose families", the report says.
In 2013 a research team from India discovered six new species in the country's north east, including one impatiens, two colocasia and three wild bananas, bringing the number of Indian banana species to 23.
Fifteen new orchids were discovered over the period, including Bulbophyllum nepalense, collected from Shivapuri National Park, Kathmandu at an altitude of 2300m above sea level. The species has "oblong dorsal sepals, the elliptic petals and oblong decurved ligulate lip with narrow pseudobulbs, the falcate, acute-acuminate lateral sepals, and two strips of papillae or short hairs on the adaxial side of the lip, close to the margins".
Ione kipgenii was also discovered by a research team from the Centre for Orchid Gene Conservation of the Eastern Himalayan Region, during a survey in the forests of the region.
Between 2009 and 2014 39 invertebrates, 26 fish, 10 amphibians, one reptile, one bird and one mammal were also discovered in the region, the report says.
WWF says climate change, road and dam construction and mining, oil and gas pose major threats to the region's biodiversity, as do invasive species, pollution and tourism. Just 25 per cent of the region's original habitats remain intact.
WWF-UK's chief adviser of species, Heath Sohl, said: "These new discoveries show that there is still a huge amount to learn about the species that share our world. It is a stark reminder that if we don’t act now to protect these fragile ecosystems, untold natural riches could be lost forever."