Species Identification

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

AttributeThe current selection is Penstemon_thompsoniae
ClassificationPenstemon Penstemon Ericopsis Caespitosi
GeneralThompson’s Penstemon. “Penstemon thompsoniae is a complex species with four or five geographical races that, at least in the Intermountain region appear to be too variable to recognize taxonomically.” N. Holmgren, Genus Penstemon, Intermountain Flora. Blooms: May to June.
Anther0.8-1.2 mm long, opening fully, but not flat, black, smooth except for the nipple-toothed cell edges.
StaminodeOrangish-to golden-yellow-bearded; fertile stamens mostly protruding.
Leaves6-18 mm (1/4-3/4”) long & 2-4 mm wide, ascending, spatulate or obovate, entire, mucronate (pointed tips), tapering to a stemmed base.
StemsLow, cespitose (cluster-forming) often mat-forming subshrub, flowering stems prostrate or ascending at a low angle in some, older stems woody, prostrate, much-branched, herbage and calyces ashy with backward pointing, flattened to stem, scale-like hairs..
InflorescenseThyrse racemiform (raceme with separate, equal-stalked flowers equally arranged along stem) in prostrate plants and paniculate (panicle: irregularly compound inflorescence of stemmed flowers) in ascending plants, the pubescence (hairs) as on the herbage.
Corolla10-18 mm (3/8-5/8”) long, the lobes blue to blue-purple to violet, somewhat bulging, the throat flat and 2-ridged above and bulged beneath, glandular-puberulent (sticky-downy) on the outer surface, the palate pale yellow-bearded.
Flower Color
Calyx4-6 mm (<1/4”) long, the segments lanceolate, the margins not ragged.
HabitatWhite calcareous clays or sandy soils in sagebrush and pinyon-juniper communities and subalpine slopes in the Charleston Mts., 1500-2000m (5000-6700’).
Range1a. Leaves to 20 mm (3/4”) long var. jaegeri Keck: stems few, upright to 14 cm (1/2”) tall, inflorescence usually distinct, cymes visible, corolla to 14 mm (1/2”) long, Charleston Mts. In Clark Co., NV. var. thompsoniiae [syn: subsp thompsoniae]: Stems tufted from buried branches to 5 cm (2”) tall, inflorescence not distinct, cymes hidden in leaves, San Bernardino Co., CA, wc & s NV, Kane Co., UT, nc AZ. 1b Leaves very short, to 12 mm (3/8”) long var. desperatus: Stems many, creeping, to 2 cm (3/4”) tall and & 17 cm (6 ¾”) long, sw UT, nearby NV.
Penstemon thompsoniae, Conners Pass