In the 2 centuries since its founding by Emperor Dom João VI, the botanical garden has grown to 141 hectares (348 acres) and added 6,000 species of tropical plants and trees to its collection. Most visitors come to enjoy the peace and beauty, meandering along the many little paths and garden trails; the bromeliad and orchid greenhouses are especially nice. Those more scientifically minded may find themselves frustrated. The gardens are run as a research institute under Federal Environment Ministry, with the result that treatment of visitors is somewhat hit-and-miss. Many trees and shrubs are labeled with common and Latin names, but there's not much more species information. Free English-language guided tours are supposed to be available (call ahead or check in at the visitor center) but the service is sporadic and unreliable.