Mimosa pudica* has an extraordinary defense system. The leaves of this plant along with its stem fold inward and droop in seconds when touched or shaken. If the disturbing force persists, it will do a second downward movement exposing sharp needles covering its stem. This is enough to expel insects. The mechanism required for this action is activated by electrical currents. These currents are similar to those used in the human nerve system. Plant reactions are not as fast as ours. However the electrical currents conducted by the nectar channels can cross a distance of 30 centimeters in just a couple of seconds. Reaction rate will be higher as the ambient temperature rises. Bottom of each leaf (at the junction of the leaf stem) is noticeably swollen. The cells here are filled with water. When the warning signal reaches here, the lower half of the water at the bottom of the swelling empties itself, whilst the upper half takes in this water. And the leaf droops down. All the leafs shut down one by one in succession like dominoes as the signal propagates through the stems. After such a defensive action the plant will need 20 minutes to refill its cells and raise its leaves. (Malcolm Wilkins, Plantwatching, New York, Facts on File Publications, 1988, s. 141-142)
Like all other living beings Allah created the plants and furnished them with perfect systems as to demonstrate His Greatness, His Might and His Infinite Wisdom. This perfection of the system created by our Lord is described in Qur’an as:
“He Who created the seven heavens in layers. You will not find any flaw in the Creation of the All-Merciful. Look again – do you see any gaps? Then look again and again. Your sight will return to you dazzled and exhausted!” (Surat al-Mulk, 3-4)
* Mimosa pudica (also called Sensitive Plant), is a creeping annual or perennial herb.