Bloomipedia
Rattlesnake master (Eryngium yuccifolium)
Photo: evangrimes via iNaturalist · CC BY 4.0 · resized

Flower profile

Rattlesnake master

Eryngium yuccifolium

Rattlesnake master (Eryngium yuccifolium) is a flowering plant in the Apiaceae family, native in the lower 48 states, blooming mostly June–August across the U.S.

Native in the lower 48

Rattlesnake master is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 8 states, and across the U.S. it's most often seen in bloom in June–August.

26states where USDA records it
8Bloomipedia state lists include it
21,494U.S. sightings*

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

On our lists for: Arkansas, Illinois, Indiana, Iowa, Kansas, Mississippi, Missouri, Wisconsin

Quick look

Eryngium yuccifolium, known as rattlesnake master, button eryngo, and button snake-root, is a perennial herb of the parsley family native to the tallgrass prairies of central and eastern North America. It grows from Minnesota east to Ohio and south to Texas and Florida, including a few spots in Connecticut, New Jersey, Maryland, and Delaware.

  • It belongs to the Apiaceae 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 26 states. USDA PLANTS
  • In Illinois, most iNaturalist sightings of it in flower come in July–August. iNaturalist
  • In Wisconsin, most iNaturalist sightings of it in flower come in July–August. iNaturalist
  • iNaturalist has 4,353 research-grade sightings of it in Illinois, ranking #24 among the 180 flowers on our Illinois list. iNaturalist
  • iNaturalist has 2,026 research-grade sightings of it in Wisconsin, ranking #70 among the 161 flowers on our Wisconsin list. iNaturalist
  • iNaturalist has 1,232 research-grade sightings of it in Missouri, ranking #50 among the 177 flowers on our Missouri list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (936 records)
Bloom time in the 8 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
IllinoisNativeJuly–August4,353
WisconsinNativeJuly–August2,026
MissouriNativefew records (16)1,232
IowaNativeJuly–August902
IndianaNativefew records (44)872
ArkansasNativeJune–July865
MississippiNativeMay–July549
KansasNativefew records (7)350

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 4 of our 8 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
Wisconsin
Not listed Not on Wisconsin endangered and threatened species list (Wis. Admin. Code NR 27.03). NatureServe: SNR, not yet ranked in Wisconsin. NR 27.03
Missouri
Not listed Not on Missouri Wildlife Code endangered species (3 CSR 10-4.111), plants. NatureServe: SNR, not yet ranked 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
Indiana
No list Indiana has no state law listing endangered or threatened plants (the DNR keeps a rare plant list, but it isn't regulatory), so we show NatureServe's Indiana ranks instead. NatureServe: SNR, not yet ranked in Indiana.
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.
Mississippi
No list Mississippi has no state law listing endangered or threatened plants, so we show NatureServe's Mississippi ranks instead. NatureServe: S5, secure in Mississippi.
Kansas
No list Kansas's endangered and threatened list (K.A.R. 115-15-1) covers animals only, so we show NatureServe's Kansas ranks for plants. NatureServe: SNR, not yet ranked in Kansas.
Rare elsewhere
Other states where NatureServe ranks it rare or missing: MD (SH), MI (S2), NE (S1), VA (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 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 rattlesnake master in 26 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Arkansas, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Jersey, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, Texas, Virginia, Wisconsin.

Illinois counties with USDA records: Adams, Alexander, Bond, Boone, Brown, Calhoun, Cass, Champaign, Christian, Clay, Clinton, Coles, Cook, Crawford, Cumberland, De Witt, DeKalb, Douglas, DuPage, Edgar, Effingham, Fayette, Ford, Franklin, Fulton, Grundy, Hancock, Hardin, Henderson, Henry, Iroquois, Jackson, Jasper, Jefferson, Jersey, Johnson, Kane, Kankakee, Kendall, Knox, LaSalle, Lake, Lawrence, Lee, Livingston, Macon, Macoupin, Madison, Marion, Marshall, Mason, Massac, McDonough, McHenry, McLean, Menard, Mercer, Monroe, Montgomery, Moultrie, Ogle, Peoria, Perry, Piatt, Pope, Randolph, Richland, Sangamon, Shelby, St. Clair, Stark, Stephenson, Vermilion, Wabash, Warren, Washington, Wayne, Whiteside, Will, Williamson, Winnebago, Woodford.

Wisconsin counties with USDA records: Columbia, Dane, Grant, Green, Iowa, Jefferson, Kenosha, Lafayette, Milwaukee, Oneida, Racine, Rock, Walworth, Washburn, Waukesha.

Missouri counties with USDA records: Adair, Barry, Barton, Bates, Benton, Boone, Caldwell, Callaway, Camden, Carroll, Carter, Cass, Cedar, Chariton, Christian, Clark, Clay, Clinton, Cooper, Crawford, Dallas, Daviess, DeKalb, Dent, Douglas, Dunklin, Franklin, Gentry, Greene, Grundy, Harrison, Henry, Hickory, Holt, Howell, Iron, Jackson, Jasper, Jefferson, Johnson, Knox, Laclede, Lafayette, Lawrence, Lincoln, Linn, Livingston, Macon, Madison, Maries, Marion, McDonald, Mercer, Monroe, Montgomery, Morgan, Newton, Nodaway, Oregon, Osage, Ozark, Perry, Pettis, Phelps, Pike, Polk, Pulaski, Putnam, Ralls, Randolph, Ray, Reynolds, Ripley, St. Clair, St. Francois, St. Louis, Ste. Genevieve, Stone, Sullivan, Taney, Vernon, Warren, Washington, Wayne, Webster, Wright.

Names, range and relatives

County records: USDA PLANTS lists it in 745 counties across 23 states; the most are in Missouri (86), Illinois (82), Florida (54).

Other Eryngium on Bloomipedia (1): Leavenworth's eryngo.

More from the Apiaceae family (16 on Bloomipedia; most observed first): Queen Anne's lace (wild carrot), Common cowparsnip, Poison hemlock, Common hedge parsley, Fennel, Golden alexanders, Goutweed, Aniseroot.

More Illinois flowers

Queen Anne's lace (wild carrot) (Daucus carota)

Queen Anne's lace (wild carrot)

Daucus carota

Introduced

🌼 Blooms in IL: June–September
Golden alexanders (Zizia aurea)

Golden alexanders

Zizia aurea

Native

🌼 Blooms in IL: April–May
Common cowparsnip (Heracleum maximum)

Common cowparsnip

Heracleum maximum

Native

🌼 Blooms in IL: May–June

Sources