What are some factors that account for plants distribution across the earth?

Question

In botany, we are discussing this. Our book is c**p and doesn't have anything. My two theories are water cycling across the globe, meaning that even dry environments still get rain occasionally; and Pangaea-when it broke apart it moved the plants with it and the plants adapted to their new enviroments and account for the numerous species we have today. Thanks for your help! Just some website would be great, I can look through them.

Answer 1

Ocean currents -- coconuts can float thousands of miles

Wind -- dandelions, milkweed

Animals - fruits and berries