Penstemon linarioides var. sileri
Syn. Fl. N. Amer. 2(1): 270. 1878.
Stems 8–40 cm. Leaves glabrous, glabrate, retrorsely hairy, or puberulent, hairs pointed, cauline 8–26 × 0.5–2 mm, blade linear. Flowers: staminode: distal 3–5 mm densely pilose, hairs yellow, to 1.2 mm, rest of distal 2–3 mm sparsely to moderately pilose.
Phenology: Flowering May–Sep(–Oct).
Habitat: Sandy to clay soils, sagebrush shrublands, oak or oak-juniper woodlands, pine forests.
Elevation: 1200–2400 m.
Ariz., Nev., Utah.
Variety sileri is known from northern Arizona, southern Nevada, and southwestern Utah. Plants with glabrous or nearly glabrous leaves from northern Arizona and southern Utah have been referred to var. viridis. As noted by N. H. Holmgren (1984), such forms occur sporadically through much of the range of var. sileri, suggesting that taxonomic recognition of var. viridis is unwarranted. Some specimens included in var. sileri from northern Arizona, especially from the Kaibab Plateau, have the habit of subsp. compactifolius (included here in var. linarioides) but the leaf pubescence of var. sileri (or var. viridis). Holmgren identified three morpho-geographic races that may warrant recognition.
"/4+timescorollathroat" is not declared as a valid unit of measurement for this property.