Snapdragon
genus of plants in the family Scrophulariaceae, more commonly known as snapdragons, from the fancied resemblance of the flowers to the face of a dragon. The taxonomy of this genus is very unclear at present. At one extreme, ITIS recognises only one species in the genus, the Garden Snapdragon, Antirrhinum majus. At the other, Thompson (1988) treated 36 species in the genus (though new species continue to be discovered, see for example Romo et al., 1995), and many modern botanist continue to discuss "Antirrhinum sensu Thompson".
Recent research in the molecular systematics of this group, and related species, by Oyama and Baum (2004), has confirmed that the genus as described by Thompson is monophyletic, provided that one species (A. cyathiferum) is removed to a separate genus, and two others (previously listed as Mohavea confertiflora and M. breviflora) are included. The species list at the right follows these conclusions. It is widely agreed that this broad group should be subdivided into three or four subgroups, but the level at which this should be done, and exactly which species should be grouped together, remain unclear. Some authors continue to follow Thompson in using a large genus Antirrhinum, which is then divided into several sections; others treat Thompson's genus as a tribe or subtribe, and divide it into several genera.
If we accept the broad genus, its sections are as follows:
- Section Antirrhinum: about 20 Old World species of perennial plants, including Antirrhinum majus, mostly native to the western Mediterranean region with a focus on the Iberian Peninsula.
- Section Saerorhinum: about 16 New World species, mostly annual plants and mostly native to California, though species are found from Oregon to Baja California Sur and as far east as Utah. Like other authors, Thompson placed A. cyathiferum in this section, but Oyama and Baum, following earlier authors, suggest that it should be reclassified in genus Lesser Snapdragon or Linearleafed Snapdragon A. orontium, is often treated in the genus Misopates.
The Garden Snapdragon is an important garden plant; cultivated varieties of this species have showy white, crimson, or yellow bilabiate flowers.
It is also important as a model organism in botanical research, and its genome has been studied in detail.
While Antirrhinum majus is the plant that is meant if the word "snapdragon" is used on its own, many other species in the genus, and in the family Scrophulariaceae more widely, have common names that include the word "snapdragon".
