Species Identification

Interested in the identification of penstemons? Please select a species then click on submit:

AttributeThe current selection is Penstemon_aridus
ClassificationPenstemon Penstemon Penstemon Humiles
GeneralStiff-leaf Penstemon Aridus means growing in a very dry location. The plants form crowded tufts when they are well-developed. Flower color will readily distinguish this species from P. laricifolius (larch-leaf penstemon, white or pink) if the leaves are all needle-like. Blooms: Late Spring and Early Summer.
Anther0.6-0.9 mm long, glabrous (smooth) sacs opening completely and normally spreading explanate (flat).
StaminodeYellow-bearded, not much expanded at the tip and just reaching the orifice
Leaves1.5-6 cm (to 2+) long & 1-5mm wide, linear and grasslike or narrowly oblanceolate at base and pointed, often folded at midrib, smooth or finely pubescent; stem leaves narrowly linear to oblong, sessile (stemless), the margins finely ciliolate-pubescent (fringed on edges).
Stems0.5-2.5 dm (2-10) tall in a tight clump of few to many stems, smooth or more commonly finely pubescent (short-hairy).
InflorescenseOf 1 to 6 loose, few-flowered verticillasters, the lower stems pressed tightly to the stem, finely glandular (sticky).
Corolla11-18 mm (1/2-3/4) long, gradually expanded in the throat, the palate lightly bearded, glandular outside.
Flower Color
CalyxThe sepals 2.5-5 mm (<1/4) long, broadly oval with white, ragged margins.
HabitatOpen, rocky valleys and plains into the mountains, approaching subalpine.
RangeSouthwestern MT and se ID to n-central WY.