Orchids are an important part of the natural ecosystem just as much as any other floras. Furthermore, it has been playing a vital role in the culture and tradition of a community, boosting the economy through horticulture and floristry as well as the medicinal and pharmaceutical sector. Orchids belong to the Orchidae family, the second-largest family of any flowering plant. Therefore, it should be noted that there are more than 25,000 species of orchids with more than 700 genera identified and accepted by scientists. It can be found around the world with different habitats, distribution, habits and colours, yet there are still many new species being uncovered every now and then.

Arunachal Pradesh is one of those regions blessed with the existence of Orchids. It is dubbed "The Orchid State of India" for no odd reason, the state has been conferred with the name because it houses about 40% of India's combined orchid species. In this blog, I will attempt to briefly introduce the different orchids that can be found in the natural vegetation of Arunachal Pradesh.

Let's continue with the series where I last left off at Orchids of Arunachal- part 1

Orchids of Arunachal

1. Calanthe brevicornu

This plant of the larger Orchidaceae family classifies as belonging to the sub-family of Epidendroideae, of the Bletiteae tribe and Bletiinae sub-tribe under the genus Calanthe. From the sites of Shergaon and T/gaon in Arunachal Pradesh, this species was collected and identified by Dr Abbareddy Nageswara Rao (former Orchidologist in State Forest Research Institute, Itanagar), who has been credited with 30+ discoveries of orchid species.

Commonly known as The Short Spurred Calanthe, Calanthe brevicornu's flower is beautifully tinted as dull purple, maroonish or brick reddish with a Raceme inflorescence and a fleshy stem. The flower of Calanthe brevicornu can size anywhere from 4cm to 4.5 cm across. One can witness the flowers bloom in spring and summer with its flowering period starting in May and ending in July. Its habitats are in temperate forests of terrestrial regions with an altitude of approximately 2000 m - 3000 m. Apart from being found in the wilds across the world, it can be found in East Kameng, Lower Subansiri, Upper Subansiri and West Kameng Districts of Arunachal Pradesh.

2. Cymbidium ensifolium

Cymbidium ensifolium, commonly dubbed as Golden-thread Orchid and is also known by various other names such as spring orchid, burned-apex orchid and rock orchid. It is also vernacularly known by different names in different regions of the world such as in Thailand; Chulan, in Japan; Suruga-ran-Shiiran, in China; Jian Lan etc. This type of species of ensifolium is classified as belonging to the family of Orchidaceae with the sub-family being Vandoideae from the genus Cymbidium. It falls under the tribe of Cymbidieae and the sub-tribe of Cymbidiinae.

Cymbidium ensifolium's flower sizes are between 3-3.5 cm across with yellowish to green coloured flowers, having Raceme type inflorescence. The flowering period starts in April and ends in the month of July and can be witnessed in spring and summer. Its habitats are in wild and terrestrial regions under Sub-tropical forests, Tropical forests, and Temperate forests with altitudes ranging from a minimum of 1000 m to a maximum of 2000 m. It can be found across the globe but in Arunachal Pradesh, one can observe these sympodial orchid plants in the Districts of East Kameng and West Kameng. Its type species is also preserved in the Tippi Orchid Centre.

3. Vanda coerulea

Commonly known as The Blue Vanda or Autumn Lady’s Tresses and vernacularly called Fa Mui in Thailand and Da Hua Wan Dai Lan in China. This coerulea species of Orchid belongs to the genus Vanda under the sub-family Vandoideae of the larger family Orchidaceae with its tribe being Vandeae and sub-tribe Vandinae. In Arunachal Pradesh, it was collected from the sites of Munna, Doimara (Digging nallah), Doimara R. F, Sessa, Khella by Dr S. N. Hegde, Dr A. N. Rao and the Department of Science and Technology.

Vanda coerulea has a beautiful pale-blue to deep blue coloured flowers and Raceme inflorescence with its flower size being 12 cm across. Its flowering season is in summer which starts in July and ends in September. It's an epiphytic orchid thriving on dwarf oak trees and having the habit of Monopodial plants, surviving mostly in sub-tropical and deciduous forests or areas with a distinct dry season in the winter, at an altitude of 1000 m to 1500 m. They can be seen thriving in the Tirap District of Arunachal Pradesh and its type species has been preserved in Tippi Orchid Centre, West Kameng District.

4. Arachnis labrosa

Commonly known as The Lip-Like Arachnis, it is a plant belonging to the Orchidaceae family and the sub-family of Vandoideae. It is vernacularly known as Zhai Chun Zhi Zhu Lan in China. This type species of labrosa come under the genus Arachnis and just like the Vanda coerulea orchid, its tribe being Vandeae and sub-tribe being Vandinae. In Arunachal Pradesh, this beautiful orchid species was observed and collected by Dr A. N. Rao from the site of Namdang Village in Changlang District.

It is an epiphytic plant having a habit of monopodial type of orchid which grows upward with a single main stem or body that develops leaves and flowers. Its Raceme inflorescence flowers are pale-yellow and orangish hue with dark brown markings, its flower size being 2-4 cm across and its stem being slender and woody. The flowering season of this orchid is summer and autumn with the period starting in August and lasting till November.

The Lip-Like Arachnis habitats in sub-tropical forests and tropical forests at an altitude of a minimum of 800 m and a maximum of 1100 m. In Arunachal Pradesh, it can be observed in the Districts of East Kameng and West Kameng. Its type species has been preserved in the Sessa Orchid Sanctuary, Bhalukpong, West Kameng District.

There are several species of orchids undiscovered in the state, and those that have been discovered have little information but for detailed reviews on the orchids mentioned above, please check the reference section.

If you want to learn more about the Orchids of Arunachal Pradesh in brief, please await part 3. Meanwhile, If you haven't yet, please check out Orchids of Arunachal- part 1.

Reference(s): Orchid Flora of Arunachal Pradesh H. J. Chowdhery 1998; Orchids of Arunachal Pradesh S. N. Hegde 1984; Orchid Database of Arunachal Pradesh

(Department of Botany, Rajiv Gandhi University); Orchids of Ziro Arunachal Pradesh Naresh Swami; Terrestrial Orchids Naresh Swami; IOSPE (Internet Orchid Species Photo Encyclopedia); www.globalorchids.info; www.catalogueoflife.org; www.tropicos.org; Flora of China.