THE ORIGIN OF GARDEN PLANTS AND THE FSU CONTRIBUTION

The South American Center

The South American Center, encompassing the tropics of the Amazonian, Brazilian, and Guayna Highlands Regions, is the area next richest in ornamental species. They account for about 600, or 12% of the world's ornamental flora. According to Vavilov the South American Center of economic plants is situated in the west mountainous regions of Ecuador, Peru, Bolivia, and west Brazil, Paraguay and Chiloe Island. Vavilov stresses that the bulk of the economically useful species are obtained from mountainous and sometimes dryer regions, but rarely from areas with a humid, tropical climate. At the same time, a large number of cultivated ornamentals occur in nature only in tropical rain forests. In the Temperate zone, most are grown only under glass and indoors. The South American plants that are usually raised in greenhouses, winter gardens and indoors are Anthurium, Caladium, Diffenbachia, Philodendron and other members of the Araceae family. Many species of Fuchsia, also the well-known gloxinia (Sinningia) are also of this origin. There are some plants that, in spite of their tropical origin, can survive in the Temperate zone (hardy in zone 6 or even 5). Among them are the rainbow plant (Caladium hybridum hort.) does well in regions belonging to zone 5 and Gunnera, a perennial with huge umbrella-like leaves, cultivated in many European countries. G. manicata, from South Brazil, is well-known and widely available in Great Britain, Germany and other European countries. South America has given horticulture wonderful well-known annuals: sage (Salvia splendens), heliotrope (Heliotropium arborescens), Verbena hybrida hort. (mainly Verbena peruviana) and morning glory (Ipomoea alba, I. purpurea, I. tricolor), which are also native to tropical America.

Most of the ornamental species of prime importance in gardening were introduced to Europe in the 18^th century. The story of their cultivation, in South America, began many years ago and with the help of carbon dating, archaeologists are able to determine the age of some plant remains. In particular, they have found that Canna had been cultivated in the Cosma Valley in Peru in 2250 B. C.