Whipple's Beardtongue - Penstemon whippleanus
State Rank Reason (see State Rank above)
Whipple's beardtongue occurs at the edge of its range in Montana, and is known here from just two collections, only one of which is recent. The species occupies high elevation, rocky habitat that is relatively unthreatened.
- Details on Status Ranking and Review
Score2-3 - Very Small to Small: Population size is imprecisely known but is believed to be <10,000 individuals.
CommentPopulation size is poorly documented.
Score2 - Regional or State Endemic or Small Montana Range: Generally restricted to an area <100,000 sq. miles (equivalent to 2/3 the size of Montana or less) or Montana contributes 50% or more of the species’ range or populations OR limited to 2-3 Sub-basins in Montana.
Area of Occupancy
Score3 - Very Low: Generally occurring in 3 or fewer Subwatersheds (6th Code HUC’s).
Score1 - Moderate: Species is restricted to a specific habitat that is more widely distributed or to several restricted habitats and is typically dependent upon relatively unaltered, good-quality habitat (C Values of 5-7).
CommentOccurs in a variety of open, subalpine habitats.
ScoreNA - Rank factor not assessed.
ScoreNA - Rank factor not assessed.
CommentPotential threats have not been analyzed, though habitat is relatively remote.
Score1 - Moderate Vulnerability: Specific biological attributes, unusual life history characteristics or limited reproductive potential makes the species susceptible to extirpation from stochastic events or other adverse impacts to its habitat and slow to recover.
Raw Conservation Status Score
9 to 10 total points scored out of a possible 13 (Rarity factors only).
Whipple's Beardtongue is a perennial herb with tufted stems that are 2-6 dm tall and arising from a shallow, branched rootcrown. The basal leaves each have an entire-margined, elliptic blade that is up to 6 cm long and a petiole of nearly the same length. The opposite stem leaves are narrower and mostly lack petioles. Foliage is glabrous below but glandular-hairy above. The inflorescence consists of 2-7 clusters of short-stalked flowers in the axils of reduced upper leaves. The tubular corolla is flared and 2-lipped at the mouth, 18-28 mm long, and blue to lavendar or cream-colored with glandular hairs on the outside. The 5 narrowly lance-shaped calyx segments are 7-11 mm long and are green throughout and glandular-hairy. The 4 anthers are glabrous, and the sterile stamen is bearded only at the tip. The fruit is a capsule that is 6-9 mm long and sparsely glandular-hairy near the top.
Flowering occurs in late July-early August.
Differing from other species of Penstemon in Montana by its large (>18 mm long), expanded (rather than narrowly tubular) flowers and a glandular inflorescence. Penstemon fruticosus, P. ellipticus, P. lyallii and P. montanus are woody at the base and have woolly anthers. Penstemon eriantherus has similar flowers but the basal leaves are narrower and have toothed margins.
Eastern ID and southwestern MT, south to UT, CO, AZ, and NM. Peripheral.
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
This species inhabits open, rocky slopes in meadows and scattered timber of the subalpine and alpine zones. The only recently documented population in Montana was found in an open meadow and adjoining forest along an avalanche chute and lower scree slopes near the headwaters of a small stream. Soils are moist, alluvial and colluvial silt loam on a gentle (5%) northwestern slope (Culver 1993). Associates include Artemisia ludoviciana (western mugwort), Bromus ciliatus (fringed brome), Carex vallicola (valley sedge), Epilobium latifolium (willow-herb), Fragaria virginiana (wild strawberry), Geum macrophyllum (large-leaved avens), Heracleum sphondylium (cow parsnip), Melica bulbosa (oniongrass), Poa glaucifolia (white poa), Trisetum spicatum (spike trisetum), and Valeriana dioica (northern valerian).
The Beaverhead County population is in a BLM Wilderness Study Area that has little grazing and no discernable threats.
- Additional ReferencesLegend: View Online Publication
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- Culver, D.R. 1993. Sensitive plant species inventory in the Centennial Valley, Beaverhead County, Montana. Unpublished report to the Butte District, Bureau of Land Management. Montana Natural Heritage Program, Helena, 42 pp. plus appendices.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Strickler, D. 1997. Northwest penstemons. Flower Press, Columbia Falls, Montana. 191 pages.