Ah yes, Dormilonas or Sensitive Plant (Mimosa pudica) in the Pea Family (Fabaceae). There are many species of Mimosa, and several of them are thigmonastic, but M. pudica is the most commonly grown horticulturally. Mimosa is also used as a common name for plants in other genera, such as the Pink Silk Mimosa (Albizia julibrissin).