ABSTRACT
Diversity of medicinal plants can be analysed from three viewpoints, phytotaxonomy, eco-physiology, and chemotaxonomical diversity. A detailed survey of the literature conducted by S. S. Samant et al. indicates that more than 50% of the ethnomedicinally important species are from the Himalayan region. The magnitude of diversity seems to be much higher than expected, as exemplified by Podophyllum hexandrum. Over-exploitation of medicinal plants has created very serious problems in terms of conservation of such species. Some of the medicinal plants are on the verge of extinction. Under extreme stress, such as that found at high altitudes, excessive restriction in the diversity of alleles for genes that regulate stress tolerance may occur and this can potentially result in fixed alleles. While mountains are often rich centres of plant diversity, the capacity to convert this diversity into economic returns through science and technology resides predominantly outside the mountains, and is mainly in the hands of private industry.
