Flower profile
Santa Maria feverfew
Parthenium hysterophorus
Santa Maria feverfew (Parthenium hysterophorus) is a flowering plant in the Asteraceae family, introduced in the lower 48 states, blooming mostly in April across the U.S.
Santa Maria feverfew is a wildflower that USDA PLANTS lists as introduced in the lower 48 states. It's on our flower lists for 2 states, and across the U.S. it's most often seen in bloom in April.
*iNaturalist research-grade observations, as of October 17, 2026.
Quick look
Parthenium hysterophorus is a herbaceous, flowering weed species in the family Asteraceae. It is one of the most common weeds across the globe. It is best known as Santa Maria feverfew, but is also referred to as Santa-Maria, whitetop weed, famine weed and congress grass. It is native to the American tropics but has since become an invasive species in East Asia, India, Australia, and parts of Africa.
- It belongs to the Asteraceae family. iNaturalist
- USDA PLANTS describes it as an herb (forb) with a annual life cycle. USDA PLANTS
- USDA PLANTS lists it as introduced in the lower 48 states and records it in 23 states. USDA PLANTS
- NatureServe lists it as not native to Texas and Louisiana. NatureServe
- In Texas, most iNaturalist sightings of it in flower come in April. iNaturalist
- iNaturalist has 8,321 research-grade sightings of it in Texas, ranking #71 among the 169 flowers on our Texas list. iNaturalist
- iNaturalist has 537 research-grade sightings of it in Louisiana, ranking #67 among the 154 flowers on our Louisiana list. iNaturalist
When does it bloom?
Conservation status
- Federal (U.S. ESA)
- Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
- NatureServe global
- GNR Not yet ranked worldwide. NatureServe
- Texas
- Not listed Not on Texas endangered and threatened plants (31 Tex. Admin. Code § 69.8), as listed by Texas Parks and Wildlife. NatureServe: SNA, not applicable (usually because it isn't native there) in Texas. 31 TAC 69.8
- Louisiana
- No list Louisiana has no state list of endangered or threatened plants separate from the federal list, so we show federal status and NatureServe's Louisiana ranks. NatureServe: SNA, not applicable (usually because it isn't native there) in Louisiana.
- Rare elsewhere
- No other U.S. state ranks it S1, S2, SH or SX.
Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.
Can you eat it?
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.
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 santa Maria feverfew in 23 states plus Washington, D.C.
recorded by USDA PLANTS on our state lists not recorded
See the full list of states
Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Hawaii, Illinois, Kansas, Louisiana, Maryland, Massachusetts, Michigan, Mississippi, Missouri, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, South Carolina, Texas, Virginia; District of Columbia.
Texas counties with USDA records: Anderson, Aransas, Bee, Bell, Bexar, Blanco, Bosque, Brazoria, Brazos, Brewster, Brooks, Brown, Burleson, Burnet, Caldwell, Cameron, Chambers, Childress, Colorado, Comal, Dallas, DeWitt, Fayette, Fort Bend, Galveston, Gillespie, Goliad, Gonzales, Grayson, Guadalupe, Hamilton, Harris, Hays, Hidalgo, Hunt, Jackson, Jefferson, Jim Hogg, Jim Wells, Karnes, Kenedy, Kerr, Kleberg, La Salle, Lampasas, Lavaca, Live Oak, Llano, Maverick, McLennan, Medina, Navarro, Orange, Parker, Refugio, Robertson, San Patricio, San Saba, Tarrant, Taylor, Terrell, Tom Green, Travis, Uvalde, Val Verde, Victoria, Walker, Waller, Wharton, Willacy, Williamson, Young, Zapata.
Louisiana counties with USDA records: Acadia, Assumption, Avoyelles, Beauregard, Caddo, Calcasieu, Caldwell, Cameron, Concordia, East Baton Rouge, East Carroll, Evangeline, Franklin, Grant, Iberia, Iberville, Jefferson, Jefferson Davis, Lafayette, Lafourche, Livingston, Madison, Natchitoches, Orleans, Ouachita, Plaquemines, Pointe Coupee, Rapides, Sabine, St. Bernard, St. Charles, St. James, St. John the Baptist, St. Landry, St. Martin, St. Mary, Tensas, Terrebonne, Vermilion, West Baton Rouge, West Feliciana.
Names, range and relatives
Native status by region (USDA PLANTS): Hawaii: Introduced; Lower 48 states: Introduced; Puerto Rico: Introduced; U.S. Virgin Islands: Introduced.
Other scientific names (synonyms in USDA PLANTS): Parthenium lobatum.
County records: USDA PLANTS lists it in 182 counties across 19 states; the most are in Texas (73), Louisiana (41), Florida (19).
Other Parthenium on Bloomipedia (2): Wild quinine, Mariola.
More from the Asteraceae family (212 on Bloomipedia; most observed first): Common yarrow, Goldenrods, White snakeroot, Sunflowers, Chicory, Black-eyed Susan, Bull thistle, Common dandelion.
More Texas flowers
Sources
- USDA, NRCS. PLANTS Database, profile PAHY.
- iNaturalist, Parthenium hysterophorus: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
- Wikipedia, Parthenium hysterophorus (lead quoted under CC BY-SA 4.0).
- Texas: Texas endangered and threatened plants (31 Tex. Admin. Code § 69.8), as listed by Texas Parks and Wildlife.
- Texas: Texas noxious and invasive plant list (4 Tex. Admin. Code § 19.300(a)).
- USFWS, ECOS species database (ESA listing check), October 17, 2026.
- NatureServe Explorer, Parthenium hysterophorus (global and state ranks).
- Edibility and toxicity: no source found (marked "not well documented").
- Photo: Loren Cassin Sackett via iNaturalist · CC BY 4.0 · resized.