Lollipop-plants (Pachystachys lutea) decorate the Conservatory of Longwood Gardens in Kennett Square, Pennsylvania. Built in 1919, the Conservatory spans 1/2 mile and houses 20 indoor gardens and 5,500 types of plants. Today, Longwood Gardens complements its horticultural displays with more than 400 musical and theatre performances, and other events, per year.