Social Latin dances (Street Latin) include salsa, mambo, merengue, rumba, bachata, bomba and plena. Until 1953, Bomba and Plena were virtually unknown outside Puerto Rico. Part of this are the influences of the Bomba and Plena rhythms. Other instruments commonly heard in plena music are the cuatro, the maracas, and accordions. La plena is a genre of music and dance native to Puerto Rico. She also acted in six episodes of the series "En plena forma", starring Alfredo Landa. All-night vigils in the Church of the Ave Gratia Plena continue for several days. A form with doubled flowers (forma "plena") is popular in gardens. Plena music is generally folkloric in nature. "Flore Pleno" (RHS's Award of Garden Merit), "Multiplex", "Plena", "Semiplena". Plena is another form of folkloric music of African origin. Plena melodies tend to have an unpretentious, "folksy" simplicity. The plena originated in Ponce around 1900. The lyrics of plena songs are usually octosyllabic and assonant. A group of reboilers attached to a pair of plena is called a calandria.