Encompassing a wide altitudinal range and situated in the Eastern Himalaya and Indo-Myanmar Global Biodiversity Hotspots, Namdapha is florally exceptionally diverse and is a delight for plant lovers! Over a 1000 plant species from more than 600 families have been recorded from the area so far, and many more are likely to be found, especially from the poorly known higher elevations.

The wide altitudinal range (200 to 4571 m ASL) supports a huge diversity of habitats. Tropical evergreen forests, dominated by species of the dipterocarp tree family, blanket vast areas of the lower elevations. The two major dipterocarp species are Dipterocarpus macrocarpus (Hollong) and Shorea assamica (Mekai), which are endemic to the region and important timber species. Other emergent tree species include Terminalia myriocarpa (Hollock), Altingia excelsa (Jutuli) and Ailanthus grandis (Borpat). As one moves up along the elevation gradient, there is a transition in habitat to tropical semi-evergreen forests, subtropical broad-leaved forests, subtropical pine forests, temperate broad-leaved forests, alpine meadows and fields of perennial snow and ice. Though primary forests cover much of the park, landslides, extensive stands of bamboo, cane growth and secondary forest dot the landscape.

Extensive stands of bamboo and cane occur in some parts of the lower elevations, especially along streams and on hill-slopes. The lower elevations also have secondary forests. Bare exposed patches as a result of landslides are frequent in this high rainfall erosion- and earthquake-prone area. Secondary vegetation also often comes up on old landslides. The subtropical and temperate broadleaved forests are dominated by oak and chestnut trees with moss-covered branches and have a predominantly bamboo (Chimonobambusa spp.) undergrowth. Further up, stunted rhododendrons replace temperate forest, and these in turn give way to several montane bamboo species without any trees. Subalpine meadows occur at the highest elevations, and some exceptionally high areas are under perennial snow. Whereas lowland forests are found in the southern and central areas of the park, the northern boundary of Namdapha (bordering the Mishmi hills and the Eastern Himalaya) has temperate and subalpine habitats.

The high diversity of plant species supports a large variety of pollinator and frugivore (fruit-eating) species. A high diversity of tree species belonging to the Moraceae (figs), Annonaceae, Anacardiaceae, Lauraceae (laurels) and Meliaceae (e.g. Aglaia, Dysoxylum) plant families are found in Namdapha that support frugivorous birds like barbets, pigeons and hornbills, and mammals like hoolock gibbons and several macaque species, civets, deer and wild pig.

Sapria himalayana, a rare parasitic plant found in Namdapha National Park

Many plants found in Namdapha are rare, endangered or endemic species. Sapria himalayana and Balanophora spp. are rare root parasites of lianas and other plants. Of the twenty taxa of gymnosperms occurring in the North-East (out of a total of 54 for India), several are found in Namdapha, species of Amentotaxus, Cephalotaxus and Larix being endemic to this region. Some species, such as Pinus merkusii (Sumatran pine) and Abies delavayi (Delavay’s Fir) are found nowhere else in India. A variety of ferns are also found and among the most prominent is the primitive tree fern Cyathea sp. Several rare orchid species including Paphiopedilum fairrieanum (Host’s slipper Orchid) and Vanda caerulea (Blue Vanda) occur in Namdapha.

The area harbours wild relatives of cultivated plants, medicinal plants, orchids and economically important plants. For example, the national park is an important reservoir of wild varieties of several cultivated species such as wild tea (Camellia caudata), wild coffee (Coffea bengalensis), wild mango (Mangifera sylvatica), wild varieties of fruits such as persimmon (Diospyros sp.), rambutan (Nephelium sp.) and mangosteen (Garcinia sp.).

The plants of Namdapha are also an indispensable part of the local peoples’ lives. Bamboo and several timber species are used extensively in the building of houses, and a variety of baskets and other vessels of household use are woven from bamboo and cane. A stemless species of rattan palm called Zalacca secunda (Jengpat) is used for roofing houses. Leaves of Livistona jenkinsiana (Tokko pat) and of a dense mat-like creeping bamboo called diji (by the Lisu) are also used for roofing. Aconitum heterophyllum (aconite), a subalpine herb, is used as poison for tipping arrows to hunt wildlife. The rare and highly valued Coptis teeta (Mishmi teeta or Golden thread root) and Aquilaria agallocha (Agar or Aloe wood) are two species of high medicinal value used for ailments ranging from digestive disorders to fevers and skin problems. The latter is very rare in Namdapha now due to excessive extraction in the past. The Lisu use many plants for treating diseases like malaria, jaundice and wound abscesses, apart from many common ailments.

Botanical surveys in Namdapha till date have been preliminary and geographically restricted. Despite the lack of comprehensive data on Namdapha’s flora, several interesting and extremely rare species such as Gnetum ula, a climbing gymnosperm and Psilotum nudum, a primitive whisk-fern have been recorded from the park. More detailed surveys and documentation will very likely result in the identification of undescribed species and the discovery of many more rare plant species.