4. Penstemon grandiflorus Nutt. (large beard-tongue)

Pl. 484 d–f; Map 2216

Stems 40–100 cm long, erect or strongly ascending, glabrous, grayish green to grayish brown or grayish purple, strongly glaucous. Basal leaves 3–16 cm long, the blade oblanceolate to spatulate or obovate, rounded to bluntly pointed at the tip (sometimes with an abrupt, minute, sharp point), mostly tapered basally to a winged petiole, the margins entire, the surfaces glabrous, strongly glaucous. Stem leaves 1.5–11 cm long, the lowermost with the blade oblanceolate to spatulate, grading into circular or depressed-ovate at the stem tip, rounded to bluntly pointed at the tip (sometimes with an abrupt, minute, sharp point), the base rounded to shallowly cordate and then clasping the stem, the margins entire, the surfaces glabrous, strongly glaucous. Inflorescences usually appearing racemose, the central axis glabrous, grayish brown or grayish purple, glaucous, with 3–9 nodes, each with a pair of leaflike, broadly ovate to circular or depressed-ovate, clasping bracts, the relatively short branches ascending, with 2 or 3 flowers per node. Calyces 7–11 mm long at flowering, glabrous, glaucous, the lobes lanceolate to narrowly ovate. Corollas 35–50 mm long, the tube abruptly enlarged well below the midpoint, strongly bilabiate, the upper lip spreading to somewhat recurved, the lower lip spreading, projecting slightly beyond the upper lip, lavender to pale bluish purple, the throat lined with darker reddish purple nectar guides but not noticeably ridged, glabrous internally and externally. Staminode white, strongly flattened toward the tip, curled-under and bearded with yellow hairs apically. Fruits 16–24 mm long. Seeds 2.5–4.0 mm long, brown to black, the brown to black ridges well-developed. 2n=16. May–June.

Uncommon, known thus far only from Atchison County (Montana to New Mexico east to Michigan, Indiana, and Texas; introduced sporadically eastward). Loess Hill prairies.