Jepson 1993, ERI 2003, Wiggins 1964

Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Perennial with few to several stems, 40-100 cm tall. Leaves: Blades triangular, basal and cauline, entire margins. Flowers: Narrow, often second inflorescence, calyx 3.5-6 mm, lobes ovate; corolla 24-33 mm, cylindric, corolla weakly or not bilabiate, scarlet, no yellow glands apparent, stamens sometimes exserted. Fruits: Septicidal capsule. Ecology: Found in sandy to clayey soils from 2,000-7,500 ft (610-2286 m); flowers February-June.

  Notes: Scarlet flowers with a nearly regular corolla, the lower lip projecting but not reflexed.

In Arizona there are three subspecies with overlapping ranges: subsp. eatonii, subsp. exsertus, and subsp. undosus. 

Subsp. eatonii differs from the other two by having glandular-puberulent leaves. Subsp. exsertus is notable for its long-exserted stamens, quite unlike the other two. Subsp. undosus has glandular-puberulent stems, and included or barely exserted stamens.  Ethnobotany: Used for spider bites, as a fumigant, an emetic, for stomach troubles, as a hemostatic, for backache, applied to snakebites, given to livestock for colic, for washing and healing burns, for ceremonial use, and the flowering period at Hopi indicates when watermelon planting is over. Etymology: Penstemon is from Greek pente, five and stemon, indicating the five stamens of the genus, while eatonii is named for American botanist Daniel Cady Eaton (1834-1895). Synonyms: None Editor: SBuckley, 2010