Penstemon

Penstemon /ˈpɛnstɪmən/, the beardtongues, is a large genus of roughly 280 species of flowering plants native to North America from northern Canada to Central America. It is the largest genus of flowering plants endemic to North America. As well as being the scientific name, penstemon is also widely used as a common name for all Penstemon species alongside beardtongues. Formerly placed in the family Scrophulariaceae by the Cronquist system, new genetic research has placed it in the vastly expanded family Plantaginaceae. The total number of species is disagreed upon due to ongoing research into if some of the named species are actually subspecies or illegitimate concepts of previously described species. They have opposite (rarely alternate or whorled), two-lipped flowers with petals fused into a 2-lipped, 5-lobed tube extending into an opening called the throat, and fruits called seed capsules. The most distinctive features of the genus are the prominent staminode, an infertile stamen, and the often densely bearded palate. The staminode takes a variety of forms in the different species; while it is typically a long straight filament extending to the mouth of the corolla, some are longer and extremely hairy, giving the general appearance of an open mouth with a fuzzy tongue protruding and inspiring the common name of "beardtongue". Most penstemons form a durable woody stem (a caudex) and have persistent basal leaves, but some are fully deciduous perennials, the remainder being shrubs or subshrubs. Heights can range from 10 cm to as much as 3 meters.