About Penstemon calycosus Small
Penstemon calycosus Small is an herbaceous perennial plant. Its stems reach 40 to 120 cm (16 to 47 inches) in height, and usually grow taller than 60 cm (24 inches). Stems grow from many-branched shallow roots, and this species is relatively long-lived for a penstemon. It produces both basal leaves (growing at the base of the plant) and cauline leaves (growing from stems). Basal leaves are present through winter, but most often wither by the time the plant flowers. All leaves are hairless and not leathery in texture. The lowest leaves measure 4.7 to 11 cm (1.9 to 4.3 inches) long, have irregularly toothed edges, are green, and are somewhat pale on their undersides. The inflorescence makes up less than one-third of the plant's total height. Flowers are arranged along the stem in 2 to 5 clusters, with two paired cymes at each node. Each cyme has one bract underneath it and holds between 1 and 15 flowers. Among penstemons native to the eastern United States, Penstemon calycosus has some of the largest, showiest flowers. The flowers are 2.0 to 3.5 cm (0.79 to 1.38 inches) long and 0.8 to 1.1 cm (0.31 to 0.43 inches) in diameter. The outer surface of the flowers is pale lavender to violet, with faint nectar guides. It blooms in late spring and early summer, from early May to early July, depending on location. Penstemon calycosus is similar to the more widespread Penstemon digitalis. It can be distinguished from Penstemon digitalis by its purple flowers and longer, tapering (attenuate) sepals. Penstemon calycosus is widespread across the eastern half of the United States, and also occurs in a small area of Canada. In the southeastern United States, it is native to the District of Columbia, Alabama, Georgia, Kentucky, North Carolina, South Carolina, Tennessee, and Virginia. According to Plants of the World Online, all reports of this species occurring in Maryland are erroneous. In the U.S. Midwest, it has been recorded in Illinois, Indiana, Michigan, Minnesota, Missouri, and Ohio. In the U.S. Northeast, it is native to Connecticut, Maine, Massachusetts, New Jersey, Pennsylvania, Rhode Island, and Vermont. It is an introduced species in New York state. In Canada, it is only known to occur in the province of Ontario. Botanist Francis W. Pennell reported that the species' range expanded in the U.S. Northeast during the early 20th century, in central New York and the lower Connecticut Valley. It grows in a variety of habitats, including forests, meadows, rocky slopes, and along stream banks. It grows on sandy or loam soils, and prefers calcareous soils, which are soils with a high content of limestone or chalk.
