Phenological Studies of High Value Endangered Medicinal Herbs: Picrorhiza kurroa and Saussurea costus in Sub-alpine Regions of Garhwal Hiamalya, Uttarakhand India (original) (raw)

International Journal of Medicinal Plants and Natural Products

In nature it is often seen that each species has a definite period, month, season in a year during which its seeds germinate, seedlings grow or show maximum vegetative growth, leaves fall (if it is deciduous), flushing of new leaves, flowering and then fruiting. The study of all these periodic behaviour of a species is called its phenology. In the life cycle of a plant each and every stage is greatly influenced by a number of environmental factors. The different stages of the plant species remain completely embedded in an environmental complex. It is very interesting to note that being fixed at a particular place, the requirement of germination, growth, flowering, fruiting, leaf fall, etc. of the species are met with at the same place but of course in different times of the year. There is a synchronization of phenological behaviour of the species and the various factors of the environment that plants are spoken of biological clocks. This is mostly regulated by external signals from the environment. But the interactions of each and every species are different at different stages of their life cycle. Thus plant phenological study has great significance because it not only provides knowledge about the plant growth pattern but it also provides the idea on the effect of environment and selective pressure on flowering and fruiting behavior (Zhang et al 2006). 1.1. About Picrorhiza kurroa Picrorhiza kurroa Royle ex Benth. (Family: Scrophulariaceae) native to Western Himalayan region, between 3000-5000m elevation (Hooker 1885; Agrawal 2003) is valued as hepato-protective, antiperiodic, cholagouge, and stomachic, antiamoebic, anti-oxidant expectorant, etc. (Singh et al 2006). The rhizome of Picrorhiza has been traditionally used to treat worms, constipation, low fever, scorpion sting, asthma and ailments affecting the liver. Picrorhiza kurroa also known as kutki is found in the NorthWestern Himalayan region from Kashmir to Kumaun and Garhwal regions in India. Kutkin is the active principal of Picrorhiza kurroa and is comprised of kutkoside and the iridoid glycoside picrosides I, II, and III. Other identified active constituents are apocynin, drosin, and nine cucurbitacin glycosides (Stuppner and Wagner 1989). Apocynin is a catechol that has been shown to