The majority of early plant studies used the Sensitive plant (M. pudica). Mimosa has much to recommend it for learning studies. They are easy to maintain, much is known about its natural history, and they have a visible leaf closure response to external stimuli. However, there are drawbacks in the use of Mimosa, for example, it takes about 15 min for a leaf to recover (Holmes and Gruenberg, 1965) and not much is known about its genome in contrast to model species such as Arabidopsis thaliana whose entire genome is known.