"Madagascar has prickly forests made up of trees adapted to dry climates, like the octopus tree."
Explanation:
- We say "made up of" instead of just "made of" to show what the forests consist of.
- It's better to use "dry climates" (plural) because there can be more than one dry area.
- Adding "the" before "octopus tree" makes it clearer that we are talking about a specific kind of tree.