Kingdom: Plantae

Phylum: Magnoliophyta -- flowering plants

Class: Magnoliopsida -- dicotyledons

Order: Scrophulariales

Family: Scrophulariaceae -- figwort

Variety: The Palouse phase is var. attenuatus.

Common Name: taper-leaf penstemon, sulphur penstemon

Species Code: PEAT3

Origin: Native to grasslands and open forests of eastern Washington, northeast Oregon, northern and central Idaho, and western Montana.

Rare: no

Form: forb, perennial, 10-70 cm tall, glandular in the inflorescence and glabrous or finely pubescent below.

Duration: perennial

Longevity: medium lifespan

Habitat Type: prairie, forest

Wetland Indicator Status: FAC

Leaves: dark green, entire or nearly so (var. attenuatus may be finely toothed); basal leaves short petiolate, lanceolate, up to 17 cm long; cauline leaves mostly sessile, lanceolate to oblong, reduced.

Flowers: borne in a dense verticillaster; calyx 4-7 mm long, sepals lanceolate to ovate or obovate, acuminate, margins entire, scarious, sometimes erose; corolla glandular-puberulent outside, blue to purple or pale yellow, 12-22 mm long, palate yellow bearded; tip of staminode yellow bearded and expanding; pollen sacs glabrous, dehiscing full length.

Flower color: blue to purple or pale yellow

Bloom: May, June, July

Bloom starts on: late May

Bloom ends on: early July

Fruit: capsule, 6-8 mm, ovoid; seeds 1 mm long.

Characteristics:
Reproduces sexually by seed.
Both yellow and blue flowered forms are found on the Palouse.
var. attenuatus, the Palouse phase, may have arisen from a P. confertus x P. albertinus cross (Strickler 1997).
Perennating organ is a woody root crown.
Flowers are perfect.
Fruit is a capsule.
var. attenuatus is a hexaploid (Keck 1945, Hitchcock et al 1969) based on x=8 (Hitchcock et al 1969).
Penstemons in general are not grazed by wildlife or livestock and have only minor medicinal uses (Strickler 1997).
Penstemon species are hosts for the larva of the Chalcedon checkerspot (Euphydryas chalcedona) butterfly (Pocewicz 2005).
Hummingbirds and bees pollinate Penstemon spp. in general.

Comments: P. attenuatus var. militaris is a species of concern (state rank SH) in Montana (Montana Natural Heritage Program 2009).

Sun requirement: full sun to partial shade

Soil moisture: xeric

Sowing time: fall

Transplant time: spring

Stratification: 90+ days cold moist

Seed yield: high

Seed harvest: easy

Seed first harvest: second season

Seed cleaning: easy

Planting duration: medium

Seed insect problem: none noted

Seed shatter: medium

Seed size: small

Seed harvest date: early August

Seed comments: holds seed well in the field

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Keywords: native perennial upland forb

Propagation:
1 protocol in the Native Plant Network
Pullman PMC

Other Propagation Information:
Seed of some Penstemon spp. loses dormancy after 2.5 years of storage (Allen et al 1990).
Reproduces sexually by seed.

Notes: Penstemon attenuatus has both cream colored and blue flowered forms locally. All penstemons make good garden plants. They grow from stratified seed. Common names include taper-leaved penstemon, sulphur penstemon. Penstemons are also known as beardtongues or beard-tongues (Skinner et al 2005).

References:
Allen, Phil S., and Susan E. Meyer. 1990. Temperature Requirements for Seed Germination of Three Penstemon Species. HortScience 25(2):191-193.

Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.

Keck, David D. 1945. Studies in Penstemon - VIII: A Cyto-taxonomic Account of the Section Spermunculus. American Midland Naturalist 33:128-206.

Kitchen, Stanley G., and Susan E. Meyer. 1992. Temperature-Mediated Changes in Seed Dormancy and Light Requirement for Penstemon palmeri (Scrophulariaceae). Great Basin Naturalist 52:53-58.

Meyer, Susan E. 1992. Habitat Correlated Variation in Firecracker Penstemon (Penstemon eatonii Gray: Scrophulariaceae) Seed Germination Response. Bulletin of the Torrey Botanical Club 119:268-279.

Meyer. Susan E., and Stanley G. Kitchen. 1992. Cyclic Seed Dormancy in the Short-lived Perennial Penstemon palmeri. Journal of Ecology 80: 115-122.

Meyer. Susan E., and Stanley G. Kitchen. 1994. Habitat-Correlated Variation in Seed Germination Response to Chilling in Penstemon Section Glabri (Scrophulariaceae). American Midland Naturalist 132:349-365.

Montana Natural Heritage Program. 2009. Plant Species of Concern. Accessed online 12/19/09 at http://mtnhp.org/SpeciesOfConcern/?AorP=p

Pocewicz, Amy. 2005. Host Plants of Palouse Butterfly Species. 2 page handout to accompany the April 2005 presentation to the Palouse Prairie Foundation.

Skinner, David M., Paul Warnick, Bill French, and Mary Fauci. 2005. Characteristics and Uses of Native Palouse Forbs in Landscaping. USDA NRCS Pullman Plant Materials Center and Palouse Prairie Foundation. Online at http://www.wsu.edu/pmc_nrcs/Docs/Forbs_for_Landscaping.pdf

Strickler, Dee. 1997. Northwest Penstemons. The Flower Press. Columbia Falls, MT.

Links:
Plant Profile from the USDA PLANTS Database
Species information from the University of Washington Herbarium