I´ve observed that the outfit of plants changes with the climatical conditions like to much sun light, to wet etc. I can´t imagine, if this happens to identical plants causing colour changes, it will also change the genes and as a consequence the kind of "medical substances". I only can think about concentrations of such pharmaca.

It can be used as identification marker. In traditional medicine (TM) system recommend to use tender leafs (which normally have flavonoid more). Considering fruit, Ripen fruits good in medicinal value. Again it all depending upon the species and also purpose of usage. But definitely colored flower and leaves is highly having bio activity.

Geographical aspects also play a role in making plants effective in treating, When I was young, I seen one folk healer growing certain medicinal plants himself in his garden to curing one particular disease, same plant, which grown other region not had that much effectiveness in curing same disease. I don't know why during my young age. Its true geographical area also very important. high or low altitude plants/ near sea shore or in plains all matters.

Good topic to discuss.

Plants change their morphology and physiology according to the change in geographical areas, for adapt to the new environnement.

These changes are controlled by genes, which can cause a structural and functional changes in the cells, therefore the bioactivity of this plant may change.

I´ve observed that the outfit of plants changes with the climatical conditions like to much sun light, to wet etc. I can´t imagine, if this happens to identical plants causing colour changes, it will also change the genes and as a consequence the kind of "medical substances". I only can think about concentrations of such pharmaca.

Plants produce many chemicals compounds that are bioactive, not just in themselves, but also in other organisms. Bioactive compounds in plants can be defined as secondary plant metabolites eliciting pharmacological or toxicological effects in man and animals. Secondary metabolites are produced within the plants besides the primary biosynthetic and metabolic routes for compounds associated with plant growth and development, and are regarded as products of biochemical “side tracks” in the plant cells and not needed for the daily functioning of the plant. Several of them are found to hold various types of important functions in the living plants such as protection, attraction or signalling. Most species of plants seem to be capable of producing such compounds.

@Massakib,

True, "Plants change their morphology and physiology according to the change in geographical areas, for adapt to the new environment" as micro-evolution and ecological studies tell us, but, Hanno is equally correct that their genetic makeup will change and they will not have same medicinal property in an environment which cause stress on them.