Mimosa pudica or 'Sensitive Plant'
Although this is a great plant for children it can tend to become a weed so be careful. Mimosa pudica or 'Sensitive Plant' gets its name from the fern like foliage which is 'sensitive' to touch.
If touched gently the leaves will simply 'fold' if given hash treatment the whole plant will droop, (at night the whole plant tends to 'fold up')
Green foliage with thorns, and pretty little 'powder puff' flowers that are a pale mauve, we would only grow it in containers and them indoors, in all but the coldest climates, where winter will usually kill them off.