The savanna gets a fair amount of rain, at least 20 inches a year.
Tundra
Desert
Grassland
Temperate forest
Asia
Antarctica
Australia
North America
Different temperatures
Midlatitudes
Rain shadows
Bajadas
Spring and summer
Winter and fall
Winter and summer
Dry and wet
They have thorns
They have toxic chemicals
A combination of the above defenses
Ants protect them
They all migrate in different directions
Their territories don't overlap
They eat different foods
They avoid each other as much as possible
Developing fire-resistant cover
Growing quickly
All of the above
Having deep roots