Western Flora:

Non-Technical Description:  Blowout penstemon is a perennial herb with 1 to many glabrous stems arising from a branched caudex or buried stem nodes. Vegetative stems are usually less than 30 cm tall and have greenish-blue, waxy, linear leaves 2.5-12 cm long and 0.3-1 cm wide. Flowering stems have narrow linear leaves at the base and broad-based, clasping, waxy leaves 0.7-3 cm wide above that taper abruptly to a narrow tip. The inflorescence is 6-16 cm long with 6-10 compact, leafy whorls of milky-blue to pale lavender flowers (rarely with pink or white flowers). Bracts of the inflorescence are broad and heart-shaped at the base and narrow to an elongate tip. Individual flowers are 23-25 mm long with tubular, bi-lobed, and faintly vanilla-scented corollas and glabrous, linear sepals. Anther sacs are 1.8-2 mm long and glabrous. Fruits are 13-16 mm long capsules with light-brown, disc-shaped seeds (Great Plains Flora Association 1986; Stubbendieck et al. 1997).  Flowers from mid June to early July. Fruits in July and August.

Similar Species:  Penstemon grandiflorus has ovate to spoon-shaped leaves that are widest near the middle, larger non-aromatic flowers, and larger fruits. P. angustifolius var. caudatus has smaller flowers.

Distribution:  Regional endemic of the Nebraska Sand Hills and the northeastern Great Divide Basin in Carbon County, Wyoming.

References: Great Plains Flora Association. 1986. Flora of the Great Plains. Univ. Kansas Press, Lawrence, KS.

Stubbendieck, J., J.A. Lamphere, and J.B. Fitzgerald. 1997. Nebraska's Threatened and Endangered Species: Blowout Penstemon. Nebraska Game and Parks Commission, Lincoln, NE.

By Walter Fertig, 14 December 2018