A botanical garden or botanic garden is a garden with a documented collection of living plants for the purpose of scientific research, conservation, display, and education. Typically plants are labelled with their botanical names. It may contain specialist plant collections such as cacti and other succulent plants, herb gardens, plants from particular parts of the world, and so on; there may be greenhouses, shadehouses, again with special collections such as tropical plants, alpine plants, or other exotic plants.
Most are at least partly open to the public, and may offer guided tours, educational displays, art exhibitions, book rooms, open-air theatrical and musical performances, and other entertainment.
Botanical gardens are often run by universities or other scientific research organizations, and often have associated herbaria and research programmes in plant taxonomy or some other aspect of botanical science. In principle, their role is to maintain documented collections of living plants for the purposes of scientific research, conservation, display, and education, although this will depend on the resources available and the special interests pursued at each particular garden. The staff will normally include botanists as well as gardeners.
The origin of modern botanical gardens is generally traced to the appointment of botany professors to the medical faculties of universities in 16th-century Renaissance Italy, which also entailed curating a medicinal garden. However, the objectives, content, and audience of today's botanic gardens more closely resembles that of the grandiose gardens of antiquity and the educational garden of Theophrastus in the Lyceum of ancient Athens.
The early concern with medicinal plants changed in the 17th century to an interest in the new plant imports from explorations outside Europe as botany gradually established its independence from medicine. In the 18th century, systems of nomenclature and classification were devised by botanists working in the herbaria and universities associated with the gardens, these systems often being displayed in the gardens as educational "order beds".
With the rapid expansion of European colonies around the globe in the late 18th century, botanic gardens were established in the tropics, and economic botany became a focus with the hub at the Royal Botanic Gardens, Kew, near London.
Over the years, botanical gardens, as cultural and scientific organisations, have responded to the interests of botany and horticulture. Nowadays, most botanical gardens display a mix of the themes mentioned and more; having a strong connection with the general public, there is the opportunity to provide visitors with information relating to the environmental issues being faced at the start of the 21st century, especially those relating to plant conservation and sustainability.
Definitions
The term tends to be used somewhat differently in different parts of the world. For example a large woodland garden with a good collection of rhododendron and other flowering tree and shrub species is very likely to present itself as a "botanical garden" if it is located in the US, but very unlikely to do so if in the UK (unless it also contains other relevant features). Very few of the sites used for the UK's dispersed National Plant Collection, usually holding large collections of a particular taxonomic group, would call themselves "botanic gardens".
The "New Royal Horticultural Society Dictionary of Gardening" (1999) points out that among the various kinds of organisations known as botanical gardens are many that are in modern times public gardens with little scientific activity, and it cited a tighter definition published by the World Wildlife Fund and IUCN when launching the "Botanic Gardens Conservation Strategy" in 1989: "A botanic garden is a garden containing scientifically ordered and maintained collections of plants, usually documented and labelled, and open to the public for the purposes of recreation, education and research."
This has been further reduced by Botanic Gardens Conservation International to the following definition which "encompasses the spirit of a true botanic garden": "A botanic garden is an institution holding documented collections of living plants for the purposes of scientific research, conservation, display and education."