The following article was written for the Orchid Species Bulletin published by the Orchid Species Society, which is based in Brisbane, Queensland in January 2001.
Bear in mind that any cultivation notes refer to the sub-tropical conditions of Southern Queensland, Australia.

Dendrobium crystallinum Rchb.f. is a widespread species that is distributed from northeast India, Burma (Myanmar)  Thailand, Cambodia, Laos and Vietnam. It often grows on small trees in exposed situations between 900-1,700 m altitude. Colonel Robson Benson discovered it in Myanmar in 1867 and sent plants to Messrs. Veitch, where it flowered at their Chelsea Nursery in 1868. Heinrich Gustav Reichenbach described it in the Gardeners' Chronicle that same year. He gave it the specific epithet from the Latin crystallinus (crystalline) for the anther cap, which is covered with glassy papillae, giving it a crystalline appearance.

Den. crystallinum can form large clumps and has tufted slender pseudobulbs that are 30-60 cm long and 8 mm diameter. They may be erect or pendulous due to their weight. Its new stems bear soft linear-lanceolate leaves that are 10-15 cm long in two ranks along their upper third. Following maturation of the pseudobulb the leaves are deciduous at the beginning of the dry winter season. Short inflorescences emerge from nodes along the upper portion of the stems mainly in summer. These bear 1-3 beautiful white flowers that are 4-5 cm across, which are very fragrant. The petals and lip have a pale to dark purple or magenta blotch on the tips and the sepals may also have a similarly colour tip. Its lip is white or yellow with a white border and the base is orange. Den. crystallinum fma. ochroleucum Guillaumin is the form that lacks the purple-magenta blotches.

Due to its generally hanging or semi-pendulous habit, Den. crystallinum is perhaps best grown in a hanging pot or basket. Alternatively it can be mounted on tree fern or cork bark, however daily watering and high humidity will be necessary in summer. In winter when it is deciduous provide it with a cooler, drier rest with occasional misting to prevent the pseudobulbs shrivelling. Plants are able to withstand very cold temperatures down to 0 ^oC if kept dry, however I would suggest a winter minimum of 10 ^oC.

References:

Baker, M.L. & C.O. Baker. (1996) Orchid Species Culture - Dendrobium. Timber Press, Portland, Oregon.

Lavarack, P.S., Harris, W. & Stocker, G. (2000) Dendrobium and its Relatives. Kangaroo Press, East Roseville, N.S.W.

Schelpe, S. & J. Stewart. (1990) Dendrobiums - An Introduction to the Species in Cultivation. Orchid Sundries Ltd, Stour Provost, Dorset.

Seidenfaden, G. (1985) Orchid Genera in Thailand XII - Dendrobium Sw. Opera Botanica, Copenhagen.

Stewart, J. & M. Griffiths. (1995) Manual of Orchids. Timber Press, Portland, Oregon.

Veitch, J. & Sons. (1887-94) A Manual of Orchidaceous Plants. H.M. Pollett & Co., London.