TL;DR: Florida has led the nation in the production of foliage plants, accounting for more than 55% of the national wholesale value since the 1960s, and Florida foliage growers continually introduce new genera and new cultivars to the market.
Abstract: INTRODUCTION Foliage plants, defined literally, would include all plants grown for their attractive leaves rather than for flowers or fruits. In general horticultural terms, however, foliage plants are mostly those with attractive foliage and/or flowers that are able to survive and grow indoors. Thus, they are used as living plants for interior decoration or interior plantscaping. Foliage plants, in common terminology, are called house plants. Foliage plants from the world’s tropical or subtropical regions provide the basis for today’s foliage plant industry. From 1956 to 1967, Aglaonema, Dieffenbachia, Dracaena, Epipremnum, Ficus, Peperomia, Philodendron, Sansevieria, Syngonium, and plants from several genera of Palmae (palm) were the major players in the industry. Philodendron dominated all other genera accounting for 50% and 36% of wholesale values in 1956 and 1967, respectively (Smith and Strain 1976). In 1975, Schefflera and ferns (Polypodiaceae) joined the list of the Census of Horticulture Specialties of the US Department of Agriculture’s National Agricultural Statistics Service (McConnell et al. 1989). However, Philodendron was still the major genus, accounting for 20% of the wholesale value. In 1988, genus Hedera was added to the list (McConnell et al. 1989). The total market segment of Philodendron decreased from 20% in 1975 to 4.7% in 1988. No single genus exceeded 10% of the market value in 1988, suggesting increased diversification in foliage plant production. Ten years later, genera Anthurium and Codiaeum, as well as bromeliads (Bromeliaceae) and cactus (Cactaceae) were added to the 1998 list (USDA 1999). The wholesale value of foliage plants in the US increased from $13 million in 1949 to $574 million in 2000 (USDA 2001). The use of foliage plants for interior decoration or interior plantscaping has become an integral part of contemporary design, playing an important role in our life (Manaker 1997). Florida has led the nation in the production of foliage plants, accounting for more than 55% of the national wholesale value since the 1960s. In addition to its favorable climate, Florida dominates the foliage market because Florida foliage growers continually introduce new genera and new cultivars to the market. This dramatically expands options for foliage plant usage in interiorscaping.
TL;DR: The NOx-sensitivity of pot plants was highest in cultivars with variegated, small or narrow leaves, and in the Moraceae family, as measured by at least one response parameter.