thorn

Examples of thorn in the following topics:

• Plant Defenses Against Herbivores

  • Other adaptations against herbivores include hard shells, thorns (modified branches), and spines (modified leaves).
  • Some Acacia tree species have developed mutualistic relationships with ant colonies: they offer the ants shelter in their hollow thorns in exchange for the ants' defense of the tree's leaves.
  • The large thorn-like stipules of Acacia collinsii are hollow and offer shelter for ants, which in return protect the plant against herbivores.

• Stem Modifications

  • Thorns are modified branches appearing as hard, woody, sharp outgrowths that protect the plant; common examples include roses, osage orange, and devil's walking stick.
  • (b) Thorns are modified branches.

• Herbivory and Pollination

  • Spines and thorns deter most animals, except for mammals with thick fur; some birds have specialized beaks to get past such defenses .

• Predation, Herbivory, and the Competitive Exclusion Principle

  • Mechanical defenses, such as the presence of thorns on plants or the hard shell on turtles, discourage animal predation and herbivory by causing physical pain to the predator or by physically preventing the predator from being able to eat the prey.
  • The (a) honey locust tree (Gleditsia triacanthos) uses thorns, a mechanical defense, against herbivores, while the (b) Florida red-bellied turtle (Pseudemys nelsoni) uses its shell as a mechanical defense against predators.

• Plant Adaptations to Life on Land

  • In turn, plants developed strategies to deter predation: from spines and thorns to toxic chemicals.