Arunachal Pradesh is known as "the Orchid State of India" because of its abundance of over 600 kinds of orchids, the second-largest family of flowering plants. Given that it is home to more than 40% of the nation's orchids, it is not surprising that the title is true. You may like to read about the documented orchids that can be found in the lovely "Land of the Rising Sun" by visiting my blogs: Orchids of Arunachal- part 1, Orchids of Arunachal- part 2, Orchids of Arunachal- part 3, Orchids of Arunachal- part 4,  Orchids of Arunachal- part 5, Orchids of Arunachal- part 6; Orchids of Arunachal Pradesh- A New Species of Orchid Identified: Schoenorchis mishmensis; Orchids of Arunachal: Orchids found in the state with the initial letter A. And this blog will highlight the Types of Calanthe species of orchids found in Arunachal Pradesh.

Calanthe biloba Lindl. 1854

A member of the Tribe Bletiteae, Subtribe Bletiinae, Genus Calanthe, and Species biloba, Calanthe biloba is a member of the Epidendroideae Sub-Family. It is known by the common name "The Two Lobed Calanthe '' and by the Chinese vernacular name "Er Lie Xia Ji Lan". It is a sympodial plant with a terrestrial habitat that can be found in subtropical and temperate forests at altitudes between 1200 and 2000 metres.

Autumn and Summer are the flowering seasons of this orchid species, and the flowering season lasts from September through October. It has flowers that are ochre-yellow and mottled purplish-brown in colour. The flower is 4 cm across and has a raceme inflorescence.  It was obtained in Arunachal by Dr. S. N. Hegde from the collection site of Sessa in the West Kameng district. Both the Sessa Orchid Center and Tipi Orchid Center in Arunachal Pradesh, India, have orchid collections of this species that visitors can view.

Calanthe brevicornu Lindl. 1833

Calanthe brevicornu belongs to the Tribe of Bletiteae and Sub-Tribe of Bletiinae, under the Genus: Calanthe and the Species are named brevicornu. It originates from the Family of Orchidaceae and the Sub-Family of Epidendroideae. It is Commonly named 'The Short Spurred Calanthe' and was first collected in Arunachal Pradesh from the Collection Site of Shergaon and T/gaon, by Dr. A. N. Rao.

This orchid thrives in a terrestrial habitat and has a sympodial plant habit. It can be found in temperate forests between 2000 and 3000 metres above sea level. The flowering season is between spring and summer, with the beginning of the flowering period in MAY and the end of the flowering period in JULY. Its stem is fleshy, and its inflorescence is a raceme with flowers that measure 4-4.5 cm wide and are dull purple or brick red in colour.

Calanthe chloroleuca Lindl. 1854

Commonly Named 'The Greenish-White Calanthe', Calanthe chloroleuca was first collected in Arunachal Pradesh from the Collection Site: Sessa; Panch Basti; Dirang in West Kameng district by Dr. S. N. Hegde and Dr. A. N. Rao. It is classified as belonging to the family of Orchidaceae and the sub-Family of Epidendroideae. It comes under the Genus: Calanthe and

Species: chloroleuca with its Tribe being the Bletiteae and Sub-Tribe being the Bletiinae.

Like other Calanthes, it also has a Sympodial habit and a Terrestrial habitat and it also prefers Temperate forests like Calanthe brevicornu, and it can be found at an Altitude Minimum of 2000 m and Maximum of 3000 m. This orchid has a raceme-like inflorescence and flowers that are 2.5 cm across and yellowish-white in colour. This orchid's flowering season is spring, which begins to flower in April and continues through June. The type specimens of this orchid species have been conserved by orchidariums like the Tipi Orchid Centre in Arunachal Pradesh's West Kameng district.

Calanthe densiflora Lindl. 1833 

In terms of its essential characteristics, it is often referred to as "the densely flowered calanthe," and in China, it is known as "Mi Hua Xia Ji Lan." It is a member of the tribe Bletiteae and subtribe Bletiinae of the Epidendroideae subfamily under the genus Calanthe and species Densiflora. The orchid blooms between the months of autumn and summer, with the flowering season lasting from September through October. It has raceme inflorescences with sheathed, covered rhizomes and yellow coloured flowers that measure 2 cm across.

This calanthe favours a terrestrial environment and has a sympodial habit like other calanthes. It can be found in subtropical forests between 1200 and 1800 metres above sea level. Dr. S. N. Hegde collected Calanthe densiflora in Arunachal Pradesh at the Selari collection site. According to experts, the districts of Siang, East Siang, Upper Siang, and West Siang in the state of Arunachal Pradesh preserve its germplasm.

Reference(s): Orchid Flora of Arunachal Pradesh H. J. Chowdhery 1998; Orchids of Arunachal Pradesh S. N. Hegde 1984; IOSPE (Internet Orchid Species Photo Encyclopedia); Terrestrial Orchids Naresh Swami; An Illustrated Guide to the Orchids of Bhutan Dhan Bahadur Gurung.

Ecology; RGU- Orchid Database of Arunachal.