Plant studies in Uttarakhand, Western Himalaya-A comprehensive review

The Indian Himalayan Region harbor about half of the flowering plant species recorded in India, of which nearly 30% species are endemic. The state of Uttarakhand, also known as the 'herbal state of India,' harbors more than 5000 species of vascular plants, of which one-third species have medicinal uses. Thus, considering the immense floral, ecological, and ethno-botanical values, the current communication aims to conduct an extensive review of scientific research on such aspects in this Himalayan state, in the absence of any such previous attempt. Based on an extensive review of 276 studies in the form of scientific peer-reviewed literature on floristics, medicinal and aromatic plants, ethno-botany, and threatened species, it is revealed that among various plant groups, vascular plants including angiosperms, gymnosperms and pteridophytes are the most studied group. Angiosperms alone accounts to 15% of the studies followed by pteridophytes and gymnosperms (10% each), whereas, the lower plants are distinctly understudied with lichens (8%) and bryophytes (6%). Interestingly, the alpine, sub-alpine, and temperate regions are explored in terms of floristic studies as compared to lower elevations such as Upper Gangetic Plains and adjacent Siwalik and Sub-Himalayan tracts in the state. The present review highlights that the remote cold-arid regions along the northern frontiers such as Nilang, Niti, Girthi, Mana, Johar, Darma, and Byans valleys, to name a few are under explored or unexplored in terms of current levels of pressure or patterns of plant diversity. Further, knowledge on the available growing stock of threatened vis-`a-vis high-value medicinal plants, information on agro-techniques of key threatened species-specific to their landscape, information on the quantity of raw material traded that eventually leads to decline in its natural population, regeneration, and survival are the matter of grave concern. Subsequently, addressing depleting ethno-botanical knowledge, studies pertaining to the lower plants, control over exploitation, illegal or pre-mature harvesting of economically valued threatened and medicinal species is the need of the hour.