Digitalis is a genus of about 20 species of herbaceous perennials, shrubs, and biennials commonly called foxgloves.
Penstemon palmeri, the Palmer's penstemon, is a perennial penstemon notable for its showy, rounded flowers, and for being one of the few scented penstemons. The plant, in the Plantaginaceae family, is named after the botanist Edward Palmer.
Penstemon parryi, the Parry's penstemon, Parry's beardtongue or desert penstemon, is a wildflower native to the Sonoran Desert of Southern Arizona and northern Mexico. It is a perennial that blooms in March and April. In the wild, plants flower in their second year. In cultivation, flowering is often achieved in the first year if seed is planted in the autumn.
Penstemon albomarginatus is an uncommon species of penstemon known by the common name white-margined beardtongue. It is native to the deserts of southern Nevada and western Arizona, as well as in two desert washes in the Mojave Desert in California. It is a perennial herb with several erect stems emerging from a taproot in the sand, their base buried beneath the surface. The stem branches are hairless and somewhat waxy in texture, reaching up to about 35 centimeters tall. The oppositely arranged leaves are oblong or widely lance-shaped, pale green edged in white, and up to 5 centimeters long. The inflorescence produces several purplish-pink tubular flowers between 1 and 2 centimeters long surrounded at the bases by toothed, white-edged sepals. The flower has some hairs in the mouth, but the staminode is hairless. The flowers are pollinated by vespid wasps and probably other insects, such as carabid beetles.
Penstemon barnebyi is a species of penstemon known by the common names White River Valley beardtongue and Barneby's beardtongue. It is native to the mountain and basin territory of central western Nevada, where it grows in sagebrush and woodland; there is also one occurrence just over the California border. This is a hairy perennial herb with erect branches reaching 30 centimeters (1 ft) in maximum height. The oppositely arranged leaves are lance-shaped and up to 7.5 centimeters (3 in) long. There are usually several located around the base of the plant. The inflorescence produces tubular flowers just over one-half centimeter long. They are light purple with a purple-striped white throat lined with yellowish hairs. The protruding staminode is covered in bright orange hairs.
Penstemon fruticiformis is a species of penstemon known by the common name Death Valley beardtongue. It is native to the deserts and nearby mountains of eastern California and western Nevada, where it grows in rocky scrub and woodland habitat. It is known from scattered occurrences around Death Valley, and only one of the two varieties occurs on the Nevada side of the border. It is a perennial herb producing spreading, multibranched, hairless and waxy stems 30 to 60 centimeters tall. The thick leaves are generally lance-shaped, folded and rolled, and up to 6.5 centimeters in length. The inflorescence produces several white or pale pinkish-lavender flowers between 2 and 3 centimeters long. The mouth of the flower bears a stark, dark line on each of its three lower lobes, nectar guides for its pollinators which probably include native bumble bees.
Penstemon heterophyllus is a species of penstemon known by the common names bunchleaf penstemon, foothill penstemon, and foothill beardtongue. It is endemic to California.
Penstemon pahutensis is a species of penstemon known by the common name Pahute Mesa beardtongue, or simply Pahute beardtongue. It is native to the desert hills and mountains of southern Nevada, including the Pahute Mesa for which it is named. It can also be found in a few areas over the border in California. It is a perennial herb growing up to 35 centimeters (14 in) tall. The paired, narrow leaves are linear to lance-shaped and up to 10 centimeters (4 in) long. The inflorescence bears blue-purple flowers up to 3 centimeters long. The inside of the wide mouth of the flower is lined with white or yellow hairs, and the staminode is coated in yellow hairs.
Penstemon procerus is a species of penstemon known by the common name littleflower penstemon. It is native to western North America from Alaska to California to Colorado, as far east in Canada as Manitoba, where it grows in mountain habitat such as meadows, often in alpine climates. It is a perennial herb forming mats of herbage with some erect stems reaching about 40 centimeters in maximum height. There are several varieties which vary in morphology, some more decumbent than others, several which are known commonly as pincushion penstemons for their matted forms. In general, the leaves are lance-shaped to oval, plentiful around the base of the plant with smaller ones arranged in opposite pairs along the stem. The inflorescence is made up of one or more clusters of tubular flowers with lipped, lobed mouths. Each flower is no more than one centimeter in length and is purple to blue in color, often with a white throat. The outside of the flower is generally hairless, while the inside may be lined with white or yellowish hairs.
Penstemon speciosus is a species of penstemon known by the common name royal penstemon. It is native to the western United States where it can be found in many types of habitat, including plateau and foothill scrub and subalpine mountain forests. It is a perennial herb growing erect to a maximum height near 60 centimeters. The leaves are usually lance-shaped and sometimes folded lengthwise, measuring up to 9 centimeters long. They are arranged oppositely and often clasp the stem at the bases. The showy inflorescence bears tubular flowers with expanded mouths, the largest reaching nearly 4 centimeters in length. The flowers come in many shades of light to deep blue, lavender, and purple, and usually have white throats.
Penstemon spectabilis is a species of penstemon known by the common name showy penstemon. It is native to southern California and Baja California, where it grows in the chaparral, scrub, and woodlands of the coastal mountain ranges.
Penstemon venustus is a species of penstemon known by the common names Venus penstemon and alpine penstemon. It is native to the northwestern United States, where it grows in many types of open habitat. It is a spreading shrub growing erect to a maximum height near 80 centimeters. The thick, stiff leaves are lance-shaped, serrated, and up to 12 centimeters in length. The showy inflorescence bears many tubular lavender flowers, the largest nearly 4 centimeters long. The mouth of the flower and the staminode are covered in long, white hairs. This penstemon is cultivated for use in wilderness landscaping in its native habitat.
Penstemon scariosus is a species of flowering plant in the plantain family known by the common name White River beardtongue. It is native to Colorado, Utah, and Wyoming in the United States.
Penstemon attenuatus is a species of flowering plant in the plantain family known by the common names sulphur penstemon and taperleaf beardtongue. It is native to the northwestern United States.
Penstemon eriantherus is a species of flowering plant in the plantain family known by the common names fuzzytongue penstemon and crested beardtongue. It is native to western North America, where it occurs in western Canada and the northwestern and north-central United States.
Penstemon alluviorum, known by the common name lowland beardtongue, is a species of flowering plant in the veronica family. It is native to the Eastern United States where it is found in alluvial lowlands, particularly of the Mississippi and Ohio Rivers.
