Flower:

Three to 7 opposite pairs of flower clusters on erect to ascending stalks arising from leaf axils in the upper plant, with 2 to 6 short-stalked flowers in each cluster. Flowers are pale violet or pinkish to purple, about ¾ inch (15 to 22 mm) long, tubular, the lower lip extending out and down with 3 lobes of similar size and shape, the upper lip erect and lobed in 2 parts somewhat smaller than the lower lobes. Inside the tube are several darker purplish lines, 4 black-tipped stamens hugging the upper part of the tube, a white style, and a yellow sterile stamen covered in short hairs at the tip end.

The floral tube is abruptly inflated from the lower third. The calyx holding the flower is green to purple and has 5 flaring lance to triangular lobes shorter than the floral tube. The calyx, flower stalks and outer surface of the petals are all densely covered in short glandular hairs.

Leaves and stem:

Leaves are basal and opposite along the stem. Basal and lowest stem leaves are somewhat variable, stalked, toothless or minutely toothed, mostly hairless, narrowly spatula shaped to oblong to narrowly egg-shaped, 1 to 3 inches (2.5 to 7.5 cm) long, up to ½ inch wide, pointed to blunt at the tip, tapering at the base. Stem leaves are somewhat smaller, erect to ascending, minutely toothed, stalkless, more rounded at the base, and reduced to bracts in the flower clusters. Stems are erect, single or a few from the base, unbranched, hairless or minutely hairy, and green to purplish.

Fruit:

Fruit is a capsule ¼ to 1/3 inch (6 to 8 mm) long containing numerous angular brown seeds.

Notes:

Slender Beardtongue is commonly found in sandy prairies and rock outcrops but tolerates a range of conditions from dry to average moisture and full sun to part shade. It is more delicate in appearance than most of our other native Penstemon species, recognized by the (usually) pale lavender to pinkish flowers and is seldom more than 15 inches tall.