Question
Is the Mimosa Pudica a tree? Or is it a plant? This tree/plant grows in Vietnam, Indonesia...

Answer
It is a shrub growing about 5 feet tall. Here is a web link to information on Mimosa pudica: By the way "plant" is the kingdom and anything with chlorophyll is a plant including trees. Everything else is classified as either an animal or mineral.
http://www.bio.miami.edu/mimosa/mimosa.html