History
Rasna was said to be bitter and useful in treating rheumatism. It was an ingredient in oils prepared for rheumatism.

Habitat
It grows from Uttar Pradesh to West Bengal and extends to the south of India.

Morphology Description (Habit)
It is an epiphytic orchid with special whitish grey coloured velamen roots for the absorption of water. The leaves are thickly coriaceous, recurved, complicate

obtusely keeled, and 15-20 cm. x 1.3-2.0 cm in size. The flowers are in 6-10-flowered racemes. Sepals are tessellated with brown lines and white margins. Petals are yellow with brown lines and yellow margins, shorter than the sepals. Lips are bluish, dotted with purple and side lobes are rising from the mouth of the spur. The spur is straight and conical. The capsules are narrowly clavate-oblong, with acute ribs and a short pedicel.

Principal Constituents
Heptacosane (C₂₇H₅₆) containing traces of the higher homologue (C₂₉H₆0) and octacosanol (C₂₈H₅₈O) containing traces of higher homologue (C₃₀H₆₂O), (C32H66O) were identified.

Pharmacology
Heptacosane and octacosanol show anti-inflammatory activity. The observations are interesting as the anti-inflammatory activity of the long-chain alkanes and alkanols range from C27 to C32 which are ubiquitous in plants1.

Toxicology
No adverse effect was reported on usage of this plant as drug.

Indications
The roots are used in bronchitis and rheumatism. It enters into the preparation of medicated oils, used externally in rheumatism and nervous troubles.

1. Gupta et. al., Indian J. med. Res., 1946, 34, 253; Basu et. al., Curr. Sci., 1971, 40, 86.