Plant Structures for Defense

Plants have special structures that function for defense, survival, and reproduction.

Structures for defense protect plants from threats Structures for defense protect plants from threats. They might die without these defenses.

Thorns Are sharp outgrowths on the stems of plants Defend the plant from being eaten by some animals

Cactus

Poisons Some plants have chemical substances designed to discourage animals from eating them. Some taste bad; some sicken or kill the predator. Some have high poison levels only until the fruit matures, then it decreases so the fruit can be eaten and seeds dispersed. Ex. Poison ivy, poison oak, sumac

Poison Ivy

Other Defense The ability to close its leaves when touched is called (thigmotropism).