Penstemon rostriflorus is a middle elevation perennial with lanceolate leaves. The flowers are bright red. The lower lip is strongly reflexed and the anthers are horseshoe shaped. Older plants have a "bushy" appearance, can form a hedge under optimal conditions and are woody towards the base. The capsules have a very long and twisted persistent style.

General: Perennial, 30-100 cm tall; stems erect to ascending, often forming a large clump, usually branched above; herbage glabrous, sometimes puberulent below; caudex woody, branched. Leaves: Basal and cauline, opposite, the basal blades oblanceolate, 2-7 cm long, 2-8 mm wide, the upper smaller, linear to lanceolate; margins entire; basal blades petiolate, cauline blades sessile. Flowers: Inflorescence elongate, secund, usually with several whorls of cymes, these 2-4 flowered; peduncles and pedicels branched; calyx 4-7.5 mm long, the lobes ovate, apex acute; corolla white tinged with pink, 24-40 mm long, abruptly expanded into a strongly inflated throat, strongly bilabiate, the upper lip projecting, slightly arched, the lower lip reflexed, sparsely bearded, red- violet guidelines on the lower lip and inside the throat, glandular-pubescent to glabrous; staminode densely bearded with long yellow hairs; fragrant; flowers March- September. Fruits: Capsule, 7-10 mm long. Ecology: Pinyon-juniper and oak woodlands, ponderosa pine forests; 900-2400 m (3000-8000 ft); Coconino, Gila, Mohave, Navajo, and Yavapai counties; southwestern U.S. Notes: Penstemon rostriflorus is a host plant for the variable checkerspot butterfly. It can be differentiated from other red-flowered penstemons by the yellow, stalked glands on the inflorescence, and its often numerous, clump-forming stems, which sit on a woody caudex. It is a highly drought-tolerant species and fairly long-lived in comparison to many other penstemons. The bright red flowers are very attractive to hummingbirds. Editor: Springer et al. 2008