The genus Phalaenopsis (moth orchids) was first defined and named by Carl Blume in1825. These distinctive-looking orchids are found throughout tropical Asia and the larger Pacific islands, extending west to Sri Lanka and South India and east to Papua New Guinea and adjacent Australia. In the north, they occur in southern China, Taiwan, and the Philippines.
Phalaenopsis are among the most commercially important orchids. In 2002, for example, they accounted for around three quarters of all orchids purchased in the United States. They are easy to grow, flourishing even on windowsills, and produce beautiful flowers that last for months. Phalaenopsis have not always been so widely grown, however. In Victorian England, orchids were extremely popular, but Phalaenopsis were rarely seen. They were more perishable than some other readily available orchids and were difficult to transport from their native tropical habitat to European greenhouses. However, since then the scale of the Phalaenopsis trade has expanded dramatically, with millions of potted Phalaenopsis sold each year in the U.S. alone. In the first half of the 20th century, advances in sterile culture techniques in France and the United States facilitated the propagation of large numbers of Phalaenopsis at low cost. In both the U.S. and Europe, some Phalaenopsis can now be purchased for less than the cost of a flower bouquet.
Typical Phalaenopsis have flowers that are round and flat with petals resembling the wings of a moth (hence the common name). Breeders have developed a variety of tetraploid hybrids (i.e., new varieties with four copies of each chromosome rather than the usual two). These tetraploid plants are often more vigorous and may produce flowers that are larger, more abundant, and longer lasting than those of typical diploids. Two species that have played a particularly important role in the development of new Phalaenopsis hybrids are P. amabilis (the first species placed in the genus) and P. aphrodite, both of which produce round, white flowers borne in a graceful spray. The native habitat of both of these species is high up in trees, but P. amabilis is native to Indonesia, whereas P. aphrodite is found from the Philippines to Taiwan.
(Christenson 2001; Frowine 2008 and references therein)
Christenson (2001) provides a detailed taxonomic treatment of all known Phalaenopsis species. Tsai et al. (2010) published a molecular phylogeny inferring relationships among Phalaenopsis species based on a data set including around 80% of the known species.