Flower profile

Foxglove beardtongue

Penstemon digitalis

Foxglove beardtongue (Penstemon digitalis) is a flowering plant in the Plantaginaceae family, native in the lower 48 states, blooming mostly May–June across the U.S.

Native in the lower 48

Foxglove beardtongue is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 6 states, and across the U.S. it's most often seen in bloom in May–June.

35states where USDA records it

6Bloomipedia state lists include it

17,638U.S. sightings*

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

On our lists for: Arkansas, Illinois, Iowa, Missouri, New Jersey, Ohio

Quick look

Penstemon digitalis is a species of flowering plant in the plantain family, Plantaginaceae. The flowers are white and are borne in summer. According to Francis W. Pennell it is a native of the Mississippi basin and its occurrences in Canada and the eastern United States are introductions. Because of this Penstemon digitalis is the most widespread species of Penstemon east of the Mississippi River.
From Wikipedia's article Penstemon digitalis, CC BY-SA 4.0.

It belongs to the Plantaginaceae family. ^iNaturalist
USDA PLANTS describes it as an herb (forb) with a perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as native in the lower 48 states and records it in 35 states. ^{USDA PLANTS}
NatureServe lists it as native to Illinois, Ohio, Missouri, Arkansas and Iowa. ^NatureServe
NatureServe lists it as not native to New Jersey. ^NatureServe
In Illinois, most iNaturalist sightings of it in flower come in May–June. ^iNaturalist
In Ohio, most iNaturalist sightings of it in flower come in June. ^iNaturalist
USDA PLANTS lists its flower color as purple. ^{USDA PLANTS}
USDA PLANTS gives its bloom period as late spring. ^{USDA PLANTS}
USDA PLANTS lists a mature height of about 4 ft. ^{USDA PLANTS}
iNaturalist has 2,279 research-grade sightings of it in Illinois, ranking #83 among the 180 flowers on our Illinois list. ^iNaturalist
iNaturalist has 2,097 research-grade sightings of it in Ohio, ranking #86 among the 186 flowers on our Ohio list. ^iNaturalist
iNaturalist has 941 research-grade sightings of it in New Jersey, ranking #102 among the 186 flowers on our New Jersey list. ^iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (1,908 records)

Bloom time in the 6 states whose Bloomipedia list includes it

State	Type	Peak bloom	Sightings*
Illinois	Native	May–June	2,279
Ohio	Native	June	2,097
New Jersey	Introduced	May–June	941
Missouri	Native	few records (43)	922
Arkansas	Native	few records (42)	549
Iowa	Native	few records (30)	309

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

State rare plant lists

Not listed Not on the official rare plant list in 5 of our 6 states.

See each state

Illinois: Not listed Not on Illinois List of Endangered and Threatened Flora (17 Ill. Adm. Code 1050), per the Endangered Species Protection Board's 2025 checklist. NatureServe: SNR, not yet ranked in Illinois. ^{IL E&T checklist 2025}
Ohio: Not listed Not on Ohio endangered and threatened plants (Ohio Adm. Code 1501:18-1-03, eff. Dec. 26, 2024). NatureServe: SNR, not yet ranked in Ohio. ^{OAC 1501:18-1-03}
New Jersey: Not listed Not on New Jersey Endangered Plant Species List (N.J.A.C. 7:5C-5.1). NatureServe: SNA, not applicable (usually because it isn't native there) in New Jersey. ^{N.J.A.C. 7:5C-5.1}
Missouri: Not listed Not on Missouri Wildlife Code endangered species (3 CSR 10-4.111), plants. NatureServe: S5, secure in Missouri. ^{3 CSR 10-4.111}
Iowa: Not listed Not on Iowa endangered, threatened and special concern plants (Iowa Admin. Code r. 571-77.3). NatureServe: S4, apparently secure in Iowa. ^{IAC 571-77.3}

Arkansas

No list Arkansas has no state law listing endangered or threatened plants, so we show NatureServe's Arkansas ranks instead. NatureServe: SNR, not yet ranked in Arkansas.

Rare elsewhere

Other states where NatureServe ranks it rare or missing: NE (S1), RI (S1). (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 edibility or poison notes on its page), USDA PLANTS) say whether it's edible or poisonous for people. ^{NC State Extension}

For petsNot well documented

It isn't on the ASPCA plant list, and NC State Extension doesn't flag it for pets.

🌿 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 foxglove beardtongue in 35 states plus Washington, D.C.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin; District of Columbia.

Illinois counties with USDA records: Adams, Alexander, Bond, Boone, Brown, Calhoun, Cass, Champaign, Christian, Clark, Clay, Clinton, Coles, Cook, Crawford, Cumberland, DeKalb, Douglas, DuPage, Edgar, Edwards, Effingham, Fayette, Ford, Franklin, Fulton, Gallatin, Greene, Grundy, Hamilton, Hancock, Hardin, Henderson, Henry, Iroquois, Jackson, Jasper, Jefferson, Jersey, Jo Daviess, Johnson, Kane, Kankakee, Kendall, Knox, LaSalle, Lake, Lawrence, Livingston, Logan, Macon, Macoupin, Madison, Marion, Marshall, Mason, Massac, McDonough, Menard, Monroe, Montgomery, Morgan, Moultrie, Ogle, Peoria, Perry, Piatt, Pike, Pope, Pulaski, Randolph, Richland, Rock Island, Saline, Sangamon, Scott, Shelby, St. Clair, Union, Vermilion, Wabash, Washington, Wayne, White, Whiteside, Will, Williamson, Winnebago, Woodford.

Ohio counties with USDA records: Adams, Ashland, Ashtabula, Athens, Auglaize, Belmont, Brown, Butler, Carroll, Champaign, Clark, Clermont, Clinton, Columbiana, Coshocton, Crawford, Cuyahoga, Darke, Delaware, Erie, Fairfield, Franklin, Fulton, Gallia, Geauga, Greene, Guernsey, Hamilton, Harrison, Highland, Hocking, Holmes, Huron, Jackson, Jefferson, Knox, Lake, Lawrence, Licking, Logan, Lorain, Lucas, Madison, Mahoning, Medina, Meigs, Monroe, Montgomery, Morgan, Morrow, Muskingum, Noble, Perry, Pickaway, Pike, Portage, Richland, Ross, Sandusky, Scioto, Stark, Summit, Trumbull, Tuscarawas, Union, Vinton, Warren, Washington, Wayne, Wood, Wyandot.

New Jersey counties with USDA records: Bergen, Burlington, Cape May, Essex, Gloucester, Hudson, Hunterdon, Mercer, Middlesex, Monmouth, Morris, Passaic, Somerset, Sussex, Union, Warren.

Growing conditions

USDA PLANTS gives Foxglove beardtongue a low shade tolerance, high drought tolerance and low moisture use. It is rated for soil pH 5.5 to 7.0 and winter lows down to -38 °F.

Shade tolerance: Low
Drought tolerance: High
Moisture use: Low
Soil textures it is adapted to: coarse, medium, fine
Soil pH range: 5.5 to 7.0
Minimum temperature tolerated: -38 °F
Frost-free days needed (minimum): 110
Annual precipitation range: 30 to 55 inches
Minimum root depth: 8 inches
Salinity tolerance: Medium
Fertility requirement: Medium
Growth rate: Moderate
Lifespan: Moderate
Active growth period: Spring and Summer
Fruit or seed: Brown · Summer to Summer
Can be propagated by: container, seed, sprigs
Commercial availability: Routinely Available

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

Names, range and relatives

Native status by region (USDA PLANTS): Canada: Introduced; Lower 48 states: Native.

County records: USDA PLANTS lists it in 783 counties across 32 states; the most are in Missouri (95), Illinois (89), Ohio (71).

Other Penstemon on Bloomipedia (16): Cobaea beardtongue, Whipple's penstemon, 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 Illinois flowers

Culver's root

Veronicastrum virginicum

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🌼 Blooms in IL: June–August

Common milkweed

Asclepias syriaca

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🌼 Blooms in IL: June–July

Prairie trillium

Trillium recurvatum

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🌼 Blooms in IL: April–May

Sources

USDA, NRCS. PLANTS Database, profile PEDI.
iNaturalist, Penstemon digitalis: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Penstemon digitalis (lead quoted under CC BY-SA 4.0).
State rare and invasive plant lists (11):
Show all 11 state lists
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Penstemon digitalis (global and state ranks).
Edibility and toxicity: NC State Extension.
Photo: Bill Keim via iNaturalist · CC BY 4.0 · resized.