Flower profile

Whipple's penstemon

Penstemon whippleanus

Whipple's penstemon (Penstemon whippleanus) is a low shrub in the Plantaginaceae family, native in the lower 48 states, blooming mostly July–August across the U.S.

Native in the lower 48

Whipple's penstemon is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 3 states, and across the U.S. it's most often seen in bloom in July–August.

7states where USDA records it

3Bloomipedia state lists include it

7,001U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Colorado, New Mexico, Wyoming

Quick look

Penstemon whippleanus, commonly known as dusky penstemon or Whipple's penstemon, is a summer blooming perennial flower in the large Penstemon genus. It is a widespread plant within the hemiboreal forests of the Rocky Mountains in North America. It is noted for the large deep purple-red flowers and a preference for high mountain elevations.
From Wikipedia's article Penstemon whippleanus, CC BY-SA 4.0.

It belongs to the Plantaginaceae family. ^iNaturalist
USDA PLANTS describes it as an herb (forb) / a subshrub with a perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as native in the lower 48 states and records it in 7 states. ^{USDA PLANTS}
NatureServe lists it as native to Colorado, New Mexico and Wyoming. ^NatureServe
In Colorado, most iNaturalist sightings of it in flower come in July–August. ^iNaturalist
USDA PLANTS lists its flower color as purple. ^{USDA PLANTS}
USDA PLANTS gives its bloom period as late summer. ^{USDA PLANTS}
USDA PLANTS lists a mature height of about 3 ft. ^{USDA PLANTS}
iNaturalist has 5,234 research-grade sightings of it in Colorado, ranking #17 among the 160 flowers on our Colorado list. ^iNaturalist
iNaturalist has 721 research-grade sightings of it in New Mexico, ranking #81 among the 152 flowers on our New Mexico list. ^iNaturalist
iNaturalist has 358 research-grade sightings of it in Wyoming, ranking #80 among the 113 flowers on our Wyoming list. ^iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (512 records)

Bloom time in the 3 states whose Bloomipedia list includes it

State	Type	Peak bloom	Sightings*
Colorado	Native	July–August	5,234
New Mexico	Native	few records (36)	721
Wyoming	Native	few records (11)	358

Conservation status

Federal (U.S. ESA): Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. ^{USFWS ECOS}
NatureServe global: G5 Secure worldwide. ^NatureServe
Colorado: No list Colorado has no state law listing endangered or threatened plants, so we show NatureServe's Colorado ranks instead. NatureServe: S4, apparently secure in Colorado.
New Mexico: Not listed Not on New Mexico state endangered plant species (19.21.2.9 NMAC). NatureServe: SNR, not yet ranked in New Mexico. ^{19.21.2.9 NMAC}
Wyoming: No list Wyoming has no state law listing endangered or threatened plants, so we show NatureServe's Wyoming ranks instead. NatureServe: S4, apparently secure in Wyoming.
Rare elsewhere: Other states where NatureServe ranks it rare or missing: MT (S2). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list.

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records whipple's penstemon in 7 states.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Arizona, Colorado, Idaho, Montana, New Mexico, Utah, Wyoming.

Colorado counties with USDA records: Alamosa, Boulder, Chaffee, Clear Creek, Custer, Delta, Dolores, El Paso, Garfield, Gilpin, Grand, Gunnison, Hinsdale, Huerfano, Jackson, La Plata, Lake, Larimer, Mesa, Mineral, Moffat, Montezuma, Ouray, Park, Pitkin, Rio Blanco, Routt, Saguache, San Juan, San Miguel, Summit, Teller.

New Mexico counties with USDA records: Bernalillo, Lincoln, Los Alamos, Mora, Rio Arriba, San Juan, San Miguel, Sandoval, Santa Fe, Taos.

Wyoming counties with USDA records: Albany, Carbon, Converse, Fremont, Hot Springs, Lincoln, Natrona, Park, Sublette, Teton.

Growing conditions

USDA PLANTS gives Whipple's penstemon a medium shade tolerance, medium drought tolerance and medium moisture use. It is rated for soil pH 7.0 to 8.0 and winter lows down to -34 °F.

Shade tolerance: Medium
Drought tolerance: Medium
Moisture use: Medium
Soil textures it is adapted to: coarse, medium
Soil pH range: 7.0 to 8.0
Minimum temperature tolerated: -34 °F
Frost-free days needed (minimum): 117
Annual precipitation range: 13 to 35 inches
Minimum root depth: 6 inches
Salinity tolerance: None
Fertility requirement: Low
Growth rate: Rapid
Lifespan: Short
Active growth period: Spring and Summer
Fruit or seed: Brown · Fall to Fall
Can be propagated by: container, seed
Commercial availability: Contracting Only

From the USDA PLANTS characteristics data for PEWH. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

County records: USDA PLANTS lists it in 84 counties across 6 states; the most are in Colorado (32), Utah (24), New Mexico (10).

Other Penstemon on Bloomipedia (16): Foxglove beardtongue, Cobaea beardtongue, Beardlip penstemon, Palmer's penstemon, Front range beardtongue, Firecracker penstemon, Large-flowered beardtongue, Sidebells penstemon, Royal beardtongue, Hot rock penstemon.

More from the Plantaginaceae family (29 on Bloomipedia; most observed first): Bird's-eye speedwell, Butter-and-eggs (common toadflax), Purple foxglove, White turtlehead, Heath speedwell, Canada toadflax, Culver's root, Texas toadflax.

More Colorado flowers

Front range beardtongue

Penstemon virens

Native

🌼 Blooms in CO: May–July

Balkan toadflax

Linaria dalmatica

Introduced

🌼 Blooms in CO: May–September

Sidebells penstemon

Penstemon secundiflorus

Native

🌼 Blooms in CO: May–June

Sources

USDA, NRCS. PLANTS Database, profile PEWH.
iNaturalist, Penstemon whippleanus: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Penstemon whippleanus (lead quoted under CC BY-SA 4.0).
Colorado: Colorado noxious weed lists A, B and C (8 CCR 1206-2, eff. May 15, 2025).
New Mexico: New Mexico state endangered plant species (19.21.2.9 NMAC).
New Mexico: New Mexico Noxious Weed List (NM Department of Agriculture, updated June 2020).
Wyoming: Wyoming state designated noxious weeds (W.S. 11-5-102(a)(xi)), as listed by the Wyoming Weed & Pest Council.
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Penstemon whippleanus (global and state ranks).
Edibility and toxicity: no source found (marked "not well documented").
Photo: Don Loarie via iNaturalist · CC BY 4.0 · resized.