HOUSEPLANT

any plant adapted for growing indoors. The most common are exotic plants native to warm, frost-free parts of the world that can be grown indoors in colder climates in portable containers or miniature gardens. Most houseplants are, therefore, derived from plants native to the tropics and near tropics. Those that make the best indoor subjects are the species that adjust comfortably to the rather warm, dry conditions that generally prevail in indoor living spaces. Although many plants can be grown successfully indoors, there are certain groups that, because of their attractiveness and relative ease of maintenance, are generally considered the best houseplants. These include the aroids, bromeliads, succulents (including cacti), ferns, begonias, and palms, all of which have long been favourites. Somewhat more demanding are those that are grown primarily for their flowersAfrican violets, camellias, gardenias, geraniums (Pelargonium species), and orchids. plant adapted for growing indoors, commonly a member of a species that flourishes naturally only in warm climates. Although the practice of growing plants indoors was known in the ancient world, houseplants did not become widely popular until after the 17th century. In 1652 an English authority on agriculture, Sir Hugh Platt, published The Garden of Eden, which discussed how plants might be grown indoors. Not long afterward, the many previously unknown species brought back to Europe from the tropics by the voyages of discovery could be found in newly built greenhouses and conservatories. Two factors contribute to the success of the huge number of species grown today as houseplants. It is essential that houseplants be easy to care for; they must be able to tolerate the fairly low levels of light and humidity found in most homes. Of course, attractiveness also plays an obvious rolehouseplants are favoured either because of their foliage, or because of the flowers they produce, or both. Although specific points vary from species to species, in general a plant's basic requirements will be met by trying to match as closely as possible its native environment. There are five aspects of a plant's environment to which attention should be paid. Additional reading Roy Hay et al., The Dictionary of Indoor Plants in Colour (1974, reissued 1983); Anthony Huxley (ed.), The World Guide to House Plants (1983); and Thomas Rochford and Richard Gorer, The Rochford Book of Houseplants, rev. ed. (1973).