This species originates from Bhutan, Northeast India (hence the epithet after Assam), Burma, China, Loas, Vietnam and Thailand. It grows in relatively low (700m) and humid areas along river valleys as an ephiphyte.
Cultivation Suggestions: Avoid frosts completely - it doesn't like getting below about 15C. Because of its origins you will need to provide partial shade, high humidity and water well. The flower spikes are slightly below the broad-leaf canopy and although semi-erect, they are slightly hidden. This can be overcome by placing the plant in a slightly raised position - hanging on the wall or on a pedestal or in a low hanging basket.
As with most of orchids, bring them inside the house while they are flowering so that they can be admired to the maximum. As soon as the flowers start to get past their peak, return them to the orchid house.
As with all Coelogynes, give them a small dose of slow release fertiliser at the start of spring and again at the start of autumn.