Latest revision as of 10:48, 29 June 2023

[edit] An overview

Floral Diversity Arunachal pradesh/ ENVIS CENTRE ON ECO – TOURISM/ Hosted by Department of Science & Technology, Sikkim 05/08/2014

The varied forest types of eastern Himalaya exhibit an enormous floristic diversity. Apart from large number of timber species, there are innumerable varieties and kinds of orchids, medicinal plants, ferns, bamboos, canes, wild relative of large number of our cultivated plants, and even plants of biological curiosi ties, such as parasites, saprophytes, etc. are found. Other important group of plants are Rhododendrons, Hedychiums and oaks etc. Orchids form a dominant group of plants with their attractive and unique blooms.

There are more than 600 species of orchids, 52 species of rhododendron, 18 species of hedychium, 16 species of oak, 18 species of canes, 45 species of bamboo in addition to large number of medicinal and aromatic plants. Arunachal Pradesh has many species of endangered, endemic, primitive, and relict flora, Magnolia Pterocarpa pterocarpa is one such primitive angiosperm, which occurs in the foot-hills. Some rare and endangered flora that occur in Arunachal Pradesh are: Amentotazus assamica in Lohit District . Rhododendron arunachalense found in Subansiri District, Rhododendron dalhousie, and Tetracentron sinense, occurring in Kameng District, Rhododendron santapaul recorded in Subansiri District.

Gomphogyne macrocarpa found in Tirap and Kameng Districts, Gymnocladus assamicus and Lithocarpus Kamengensis available in Kameng district. Rhynchoglossum lasulinum in kameng and Subansiri District. Dendrocalamus sahni in Subansiri District. Hypericum griffitthii in Kameng District, Coptis teeta of Dibang Valley Districts, etc.

The State harbours about 52 species of of Rhododendrons, 18 species of Hedychium , 16 species of Qaks, 33 species of Coniters and a large number of fems and lichens.

About 500 species of orchids occur in Arunachal Pradesh. These include about 140 species of terrestrial orchids with 15 saprophytes and about 340 epiphytes found in the different forest types. The prominent species are: Cymbidium ansifolium , C, grandiflorum, Coelogyne corymbosa. Dendroblum aphylla, D. fimbriatum var occulatum, D. densiflorum, Calanthe masuca, Phaius flavus, Paphiopedilum. Tairriearum, venustum renanthera imschootiana, vanda coenulea , etc. Rhynchostylis refusa is the state flower of Arunachal pradesh.

The vegetation of Arunachal Pradesh falls under four broad climatic categories and can be classified in five broad forest types with a sixth type of secondary forests. These are tropical forests, sub-tropical forests, pine forests, temperate forests and alpine forests

[edit] Balsom species

[edit] Discovery: October 2017

Shiv Sahay Singh, 16 balsam species found in 5 years in Arunachal, October 8, 2017: The Hindu

Locations in Arunachal Pradesh where the balsom species were discovered, October 2017;
From: Shiv Sahay Singh, 16 balsam species found in 5 years in Arunachal, October 8, 2017: The Hindu

Impatiens lohitensis;
From: Shiv Sahay Singh, 16 balsam species found in 5 years in Arunachal, October 8, 2017: The Hindu

Impatiens zironiana;
From: Shiv Sahay Singh, 16 balsam species found in 5 years in Arunachal, October 8, 2017: The Hindu

Impatiens paramjitiana;
From: Shiv Sahay Singh, 16 balsam species found in 5 years in Arunachal, October 8, 2017: The Hindu

Impatiens pathakiana;
From: Shiv Sahay Singh, 16 balsam species found in 5 years in Arunachal, October 8, 2017: The Hindu

Impatiens rugosipetala;
From: Shiv Sahay Singh, 16 balsam species found in 5 years in Arunachal, October 8, 2017: The Hindu

Discovery of new species crucial as balsam varieties are facing a threat to their habitat from fast-changing landscape of the region

In August 2017, a research paper describing Impatiens walongensis, a new species of balsam, was published in the peer-reviewed scientific journal Phytotaxa.

The species was discovered from Arunachal Pradesh’s Anjaw district, one of India’s easternmost. About a meter tall with ovate elliptical leaves and light pink flowers, the plant was named after Walong, the locality where it was found. Impatiens walongensis is the latest but not the only new discovery of balsam in Arunachal Pradesh.

In 2017 alone, scientists discovered and published their findings on five other new species of balsam, taking the total number of balsam species discovered this year to six.

Impatiens arunachalensis, which bears purple flowers and a pink throat, was discovered from the Upper Siang district. Since only 50 plants of the species were found at a particular location, scientists described the conservation status of the plant as critically endangered.

Another species, Impatiens zironiana, with lanceolate pale yellow floral buds flowering and fruiting in the rainy season from July to September, was discovered from the Lower Subansiri district.

Two more species of balsam, Impatiens rugosipetala from the State’s Lower Dibang valley, and Impatiens tatoensis from the West Siang district, were also discovered and described earlier this year.

“Three new species of balsam were discovered from Arunachal Pradesh in 2016, and five [were discovered] in 2015. Since 2013, at least 16 new species of plants under the genus Impatiens, commonly referred to as balsam, have been discovered from Arunachal Pradesh,” said Rajib Gogoi, a scientist with the Botanical Survey of India (BSI), who has been working on balsams in Arunachal Pradesh since 2012, told The Hindu.

He said that botanists have found 55 species of balsam from the northeastern State, 16 of which are new discoveries to science.

Soil requirement

Known for their starkly differing flower shapes, which are produced along the stem with vivid colours like pink, red, white, purple and yellow, balsams grow in rich moist soil. Across the world, about 1,000 species of these angiosperms or closed seeded plants are known to occur.

In India, about 210 balsam species were known till these new discoveries from Arunachal Pradesh emerged. Now, the number of balsam species has increased to 230.

“What makes the Impatiens interesting is the high endemism among these plants. In most cases, while collecting the specimens, only a handful of plants are spotted. Since these plants have a very small habitat, they face a threat from the fast-changing landscape of the region,” said Souravjyoti Borah, another botanist associated with these discoveries.

Mr. Borah, who has been working with Mr. Gogoi on genus Impatiens, pointed out that inaccessibility and the difficult terrain of the region were among the reasons why it took so long for the new species to be discovered.

The researchers also had to dissect and study their morphology in the field itself.

Study on hybrids

Both botanists emphasise that balsams have immense horticultural importance. Studies on hybrids of the plants have been undertaken in parts of the country to produce flowers that can sustain in different environmental conditions. Different hybrids can be created from wild balsam species, so it is important to know the actual number of balsam species in the wild, Mr. Borah said.