That in plants the most valuable
active substances are formed and accumulate in plants during certain periods of their development, so the workpiece is performed at certain times. Distribution of these substances in plants is uneven: some have (a lily, bearberry, bilberry, plantain, trifoli, birch, digitalis, etc.) are concentrated in the leaves, while others (with valerian, Potbelly, sorrel horse, burnet, licorice, rhubarb and etc.) - in the roots and rhizomes, third (with lime, chamomile, immortelle, hawthorn, tansy, cornflower, etc.) - in the flowers, the fourth (the wild rose, wild strawberry, viburnum, blueberry, juniper, raspberry, zhostera) - in the fruit, etc. This defines the so-called raw morphological affiliation of medicinal plants.
In too many cases, the therapeutic effect is not due to any one substance, and with all natural complex of different substances in it.