Large Flowered Beardtongue - Penstemon grandiflorus
State Rank Reason (see State Rank above)
Rare in Montana, where it is known from only a few sites on the plains of eastern Montana.
Large Flowered Beardtongue is a stout perennial herb with 1-2 erect stems that are 5-10 dm tall and arising from a taproot surmounted by a woody, usually unbranched crown. The spoon- to egg-shaped basal leaves are 3-16 cm long and have petioles and entire margins. The opposite, clasping stem leaves are shorter and broadly oblong. Foliage is glabrous, thickish, and covered with a thin, bluish wax. The inflorescence consists of 3-7 clusters of 2-4 short-stalked flowers in the axils of the reduced upper leaves. The tubular corolla is flared and 2-lipped at the mouth, 35-48 mm long, and pink to lavender or pale blue. The 5 broadly lance-shaped calyx segments are 7-11 mm long and usually green throughout. The 4 anthers are glabrous.
Flowering and fruiting April-July.
The combination of exceptionally large flowers and glabrous inflorescence and anthers distinguish this species from others in Penstemon. It most closely resembles P. nitidus but the latter has a corolla less than 20 mm long. A hand lens may be required for identification.
MT to IN, south to TX. One collection from Custer County; a collection from Phillips County represents a reclamation planting (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Sandy soil of valleys on the plains.
Ecological Systems Associated with this Species
- Commonly Associated with these Ecological Systems
- Additional ReferencesLegend: View Online Publication
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- Heidel, B. L. 1996. Noteworthy collections - Montana. Madrono 43(3):436-440.
- 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.
- USDA, Agricultural Research Service. 1980. [Letter of December 3 to L. Dean Culwell containing the herbarium list for plant specimens on file at the Livestock and Range Research Station]. 13 pp.