Penstemon davidsonii Greene
Davidson's penstemon
Plantaginaceae (Mare's-tail family)
(Previously in Scrophulariaceae)

Introduction to Vascular Plants


© Virginia Skilton     (Photo ID #34030)


E-Flora BC Static Map

Distribution of Penstemon davidsonii
Click here to view the full interactive map and legend

Species Information

Low-shrubby perennial herb, woody at the base, with or without a taproot; stems much-branched, creeping, forming dense mats; flowering shoots 5-10 cm tall, minutely hairy.
Opposite, evergreen, smooth but sometimes glandular-spotted, primary leaves short-stalked, thick and firm, the blades elliptic to circular, entire or minutely saw-toothed, 0.5-2 cm long, usually blunt-tipped; leaves of the flowering shoots few, unstalked, small, often bract-like, less than 1 cm long.
Inflorescence a compact, few-flowered, terminal raceme, the bracts and stalks somewhat glandular-hairy; corollas purple to blue-lavender, tubular, 2-3.5 cm long, distinctly 2-lipped, smooth on the outside, hairy within on the lower lip near its base and on a pair of hairy ridges; calyces 7-10 mm long, smooth to thinly glandular-hairy, 5-lobed, the lobes lanceolate to narrowly egg-shaped; fertile stamens 4, the anthers densely white-woolly; sterile stamen half as long as the fertile stamens, long yellow-bearded toward the tip.
Capsules, 8-11 mm long; seeds numerous, angled, narrowly winged, about 1.5 mm long.
Two sympatric, poorly defined (at least in BC) varieties occur in BC:

1. Leaves entire, tending to be broadest above the middle; infrequent................. var. davidsonii

1. Leaves minutely saw-toothed, tending to be broadest near or below the middle; the common variety.................. var. menziesii (Keck) Cronq.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.


Ecological Framework for Penstemon davidsonii

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
1715 25 2410
Slope Gradient (%)
42 0 119

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

180 37 355
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 0 8
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

AT(8), CMA(14), CWH(5), ESSF(33), ICH(1), IDF(1), MH(11), MS(8)

Habitat and Range

Dry rock outcrops, slabs, ledges and talus slopes in the montane to alpine zones; frequent in BC in and west of the Coast-Cascade Mountains to 55degreeN, rare on the Queen Charlotte Islands; S to CA.

SourceThe Illustrated Flora of British Columbia