The Botanic Garden of Viterbo
The Botanic Garden of the University of Tuscia is an institution created to support teaching, research, educational and recreational facilities, is an ideal outdoor laboratory and place of culture and preservation, promotes biosystematic studies and experiments on the acclimation ability of different plant species, in collaboration with the local, national and international scientific community.
In addition to the ex situ conservation of plant species obtained through the care of the collections, and the sampling, storage and exchange of seeds, it operates for the habitat preservation, by means of plant diversity in the natural environment directly, in collaboration with the Museum Herbarium and the Tuscia Germoplasm Bank, using in situ conservation techniques.
The Botanical Garden, inaugurated in 1991, is located near a sulphurous thermal spring in the natural area of the Bullicame Park (9 hectares). It covers an area of approximately 6 hectares, gently sloping, up to a travertine platform which stops abruptly forming two almost vertical walls.
The area is rich in Etruscan and Roman archaeological remains and it is believed that there was located Fano Voltumna, a place sacred to the Etruscans; in later times, the area had important Roman thermal baths. The importance and the area's reputation is evidenced by several quotations in the Cantos of Dante's Inferno. Even during the Medieval period and until the end of the nineteenth century, the area overlaid great importance for the economy of the City of Viterbo, because destined to maceration of hemp and flax in the reservoirs connected to the source of hot sulphurous water through a system of channels.
Plant collections
Plant collections are organized according to taxonomic and phytogeographic criteria and are compatible with the climatic and soil conditions of the area, characterized by strong thermal variations (min -10° C or max 40° C) and a highly calcareous soil. The reservoirs and channels were recovered as ponds and streams for the reconstruction of aquatic and marsh plants.
At the entrance is a legumes collection, with both shrub and tree species; away is a rose garden that hosts over two hundred specimens of Rosa, with different species and their hybrids, both natural or artificial. The Garden of simples, reminiscence of the origin of the botanical gardens, is divided into plots on which more than 100 phytotherapeutic species are cultivated; just in front, it was realized the collection of "useful plants": textile, dyeing and used in perfumery, with specimens of Linum usitatissimum L. (common flax), Gossypium herbaceum L. (cotton), Lavandula stoechas L. (lavender), Papaver rhoeas L. (poppy), etc..
The palm grove houses several species which, although being particularly sensitive to low temperatures, are able to vegetate also thanks to the heating of soils by the hot underground aquifer. Nevertheless, in the coolest months, it is essential to protect the most sensitive species, such as Phoenix dactilifera L. (date palm). The reconstruction of the Mediterranean maquis was carried out on a slightly sloping area, imagined as a hill that slopes down to the sea, housing several species of sclerophyllous evergreen. Another area accommodates a collection of spontaneous Italian orchids consisting of many species collected in natural environments or reproduced by in vitro cultivation techniques.
The Arboretum (dendrological collection) occupies the central part of the Garden and includes plants arranged according to their place of origin. The Asian continent is represented by several species, among which stand out Ginkgo biloba L. (ginko), Cycas revoluta Thunb. (cycad), Melia azedarach L. (bead-tree). The characteristic species of the European continent mainly belong to the genera Acer, Alnus, Quercus, Sorbus, Viburnum, as well as Pinus, Abies, Picea, Taxus, Juniperus and others. Among the South American species are present Araucaria araucana Kock (monkey tail tree) and Cortaderia selloana (Schult. et Schult.) Asch. et Graebn. (pampas grass). In the western part of the arboretum live specimens originating in Canada, such as Liriodendron tulipifera L. (tulip tree) and Acer saccharum Marshall (sugar maple), while in the south-western have been planted Californian species as Sequoiadendron giganteum (Lindl.) Buchh. (giant sequoia) and Chamaecyparis lawsoniana (Murray) Parl. (Lawson cypress or false American cypress).
The Botanical Garden has also a collection of Italian and exotic ferns, arranged according to the family names. The collection is enriched by some specimens of tree ferns as Dicksonia antarctica Labill., as well as species which are rare in the Latium region as Ophioglossum vulgatum L. and Osmunda regalis L. Inside the Tropical Greenhouse, renovated in 2009, it has been recreated a warm and humid environment, with temperatures ranging from 18° C in winter and 30° C in summer, and the humidity is constantly maintained between 85 and 90%. It houses a collection of plants of tropical forests; among the species found there are some cycads, many ficus, Coffea arabica L. (coffee plant), Piper geniculatum Sweet (pepper), Musa basjoo Siebold & Zucc. ex Linuma (banana), Gossypium herbaceum L. (cotton), etc.. There are also several species of epiphytic orchids, as Phalenopsis spp., Stanhopea tigrina Bateman ex Lindl, Angraecum longicalcar (Bosser) Senghas and terricolous ones as Cymbidium spp.; in small tanks are also cultivated aquatic species.
Desert environments are hosted on the travertine outcrop and the vertical walls; particularly sunny and sheltered from the north winds, here are accommodate succulent plants from Africa and America. Noteworthy are the collections belonging to the genera Opuntia, Cereus, Euphorbia, Agave, and Aloe. The specimens more sensitive to low temperatures, as some Kalanchoe, Euphorbia, and numerous species of Aloe and Aeonium, are grown in a heated greenhouse in the upper part of the Botanical Garden. The flora of the Australian sub-tropical zone develops at the bottom of the Garden, around a pond, and is represented by many species of eucalyptus, acacia, callistemon, melaleuca, etc.; plants of the southern hemisphere, as specimens of Cordyline australis (G. Forst.) Hook, are also present. This area, located in south and sheltered from cold winds, has a microclimate that makes it suitable to host plants that in other situations couldn’t tolerate the rigors of winter.
