A large family of dicotyledonous plants, numbering about 3000 species in some 220 genera. The family, commonly called the foxglove or figwort family, is distributed worldwide though the greatest concentration of species is in northern temperate regions. Most of its members are herbaceous. The leaves occur in a variety of forms but always lack stipules. There is also a range of flower and inflorescence types. The flowers are usually irregular and often two-lipped, as in the snapdragons (Antirrhinum, Misopates) and toadflaxes (Linaria, Cymbalaria). However in the mulleins (Verbascum) and speedwells (Veronica) the flower is almost actino-morphic. In many flowers there is a reduction in the number (assumed originally to have been five) of floral parts. For example, figworts (Scrophularia) only have four stamens, and speedwells have four sepals and four petals and only two stamens. The fruit is usually a dehiscent capsule. Few members of the family are of economic importance though many genera, e.g. Calceolaria, Hebe, Mimulus, Antirrhinum, include ornamental varieties. Some species are parasitic on the roots of other angiosperms, especially grasses, and may be serious weeds, e.g. Striga (witchweeds). The foxglove (Digitalis purpurea) is the source of the drug digitalin (see cardiac glycoside). |
