Flower profile

Maximilian sunflower

Helianthus maximiliani

Maximilian sunflower (Helianthus maximiliani) is a flowering plant in the Asteraceae family, native in the lower 48 states, blooming mostly August–October across the U.S.

Native in the lower 48

Maximilian sunflower 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 August–October.

37states where USDA records it

6Bloomipedia state lists include it

10,061U.S. sightings*

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

On our lists for: Kansas, Nebraska, North Dakota, Oklahoma, South Dakota, Texas

Quick look

Helianthus maximiliani is a North American species of sunflower known by the common name Maximilian sunflower.
From Wikipedia's article Helianthus maximiliani, CC BY-SA 4.0.

It belongs to the Asteraceae 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 37 states. ^{USDA PLANTS}
NatureServe lists it as native to Texas, Oklahoma, Kansas, South Dakota, Nebraska and North Dakota. ^NatureServe
In Texas, most iNaturalist sightings of it in flower come in September–October. ^iNaturalist
USDA PLANTS lists its flower color as yellow. ^{USDA PLANTS}
USDA PLANTS gives its bloom period as late summer. ^{USDA PLANTS}
USDA PLANTS lists a mature height of about 5 ft. ^{USDA PLANTS}
iNaturalist has 7,250 research-grade sightings of it in Texas, ranking #88 among the 169 flowers on our Texas list. ^iNaturalist
iNaturalist has 447 research-grade sightings of it in Oklahoma, ranking #82 among the 159 flowers on our Oklahoma list. ^iNaturalist
iNaturalist has 385 research-grade sightings of it in Kansas, ranking #65 among the 151 flowers on our Kansas list. ^iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (523 records)

Bloom time in the 6 states whose Bloomipedia list includes it

State	Type	Peak bloom	Sightings*
Texas	Native	September–October	7,250
Oklahoma	Native	few records (37)	447
Kansas	Native	few records (8)	385
South Dakota	Native	few records (1)	167
Nebraska	Native	few records (5)	160
North Dakota	Native	few records (12)	63

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
Texas: Not listed Not on Texas endangered and threatened plants (31 Tex. Admin. Code § 69.8), as listed by Texas Parks and Wildlife. NatureServe: SNR, not yet ranked in Texas. ^{31 TAC 69.8}
Oklahoma: No list Oklahoma has no state law listing endangered or threatened plants, so we show NatureServe's Oklahoma ranks instead. NatureServe: SNR, not yet ranked in Oklahoma.
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: S5, secure in Kansas.
South Dakota: No list South Dakota's endangered and threatened list (ARSD 41:10:02) covers animals only, so we show NatureServe's South Dakota ranks for plants. NatureServe: SNR, not yet ranked in South Dakota.
Nebraska: Not listed Not on Nebraska threatened and endangered species (163 Neb. Admin. Code ch. 4, § 004). NatureServe: SNR, not yet ranked in Nebraska. ^{163 NAC 4-004}
North Dakota: No list North Dakota has no state law listing endangered or threatened plants, so we show NatureServe's North Dakota ranks instead. NatureServe: SNR, not yet ranked in North Dakota.
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?

For peopleEdible (per NC State Extension)

NC State Extension notes: “This sunflower provides food for birds and livestock.” ^{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. For context only: ASPCA lists a related species, Helianthus angustifolius (“Sunflower”), as non-toxic to dogs and cats. That doesn't tell us about this species, so keep pets away to be safe. ^ASPCA

🌿 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 maximilian sunflower in 37 states.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Arkansas, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Virginia, Washington, West Virginia, Wisconsin, Wyoming.

Texas counties with USDA records: Bandera, Bastrop, Bell, Bexar, Blanco, Bosque, Brazoria, Brazos, Brown, Burnet, Clay, Collin, Comal, Coryell, Crosby, Dallas, Eastland, Edwards, Erath, Fayette, Galveston, Garza, Gillespie, Grayson, Grimes, Hamilton, Hardeman, Harris, Hays, Hemphill, Hunt, Kendall, Kerr, Lamar, Lavaca, Leon, Lubbock, McLennan, Medina, Mills, Montague, Montgomery, Navarro, Parker, Potter, Randall, Rockwall, Shackelford, Sutton, Tarrant, Taylor, Travis, Val Verde, Walker, Washington, Williamson, Wilson.

Oklahoma counties with USDA records: Alfalfa, Beaver, Bryan, Cleveland, Comanche, Garfield, Grady, Greer, Marshall, McClain, Oklahoma, Payne, Pontotoc, Tulsa, Woods, Woodward.

Kansas counties with USDA records: Allen, Anderson, Atchison, Barber, Barton, Bourbon, Brown, Butler, Chase, Chautauqua, Cherokee, Cheyenne, Clark, Clay, Cloud, Coffey, Comanche, Cowley, Crawford, Dickinson, Douglas, Edwards, Elk, Ellis, Ellsworth, Ford, Franklin, Geary, Graham, Gray, Greenwood, Hamilton, Harper, Harvey, Hodgeman, Jefferson, Jewell, Johnson, Kearny, Kingman, Kiowa, Labette, Lane, Leavenworth, Lincoln, Linn, Logan, Lyon, Marion, Marshall, McPherson, Meade, Miami, Mitchell, Montgomery, Morris, Nemaha, Neosho, Ness, Osage, Osborne, Ottawa, Pottawatomie, Pratt, Reno, Republic, Rice, Riley, Rooks, Rush, Russell, Saline, Scott, Sedgwick, Shawnee, Sheridan, Smith, Stafford, Stevens, Sumner, Thomas, Trego, Wabaunsee, Washington, Wilson, Woodson, Wyandotte.

Growing conditions

USDA PLANTS gives Maximilian sunflower a high shade tolerance, medium drought tolerance and medium moisture use. It is rated for soil pH 6.0 to 8.0 and winter lows down to -13 °F.

Shade tolerance: High
Drought tolerance: Medium
Moisture use: Medium
Soil textures it is adapted to: coarse, medium, fine
Soil pH range: 6.0 to 8.0
Minimum temperature tolerated: -13 °F
Frost-free days needed (minimum): 145
Annual precipitation range: 14 to 35 inches
Minimum root depth: 16 inches
Salinity tolerance: Low
Fertility requirement: Medium
Growth rate: Rapid
Lifespan: Moderate
Active growth period: Summer and Fall
Fruit or seed: Brown · Summer to Fall
Can be propagated by: bare root, seed, sprigs
Commercial availability: Routinely Available

From the USDA PLANTS characteristics data for HEMA2. 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: Native; Lower 48 states: Native.

Other scientific names (synonyms in USDA PLANTS): Helianthus dalyi.

County records: USDA PLANTS lists it in 555 counties across 30 states; the most are in Kansas (87), Texas (57), Minnesota (52).

Other Helianthus on Bloomipedia (5): Sunflowers, Common sunflower, Cucumberleaf sunflower, Narrowleaf sunflower, Prairie sunflower.

More from the Asteraceae family (212 on Bloomipedia; most observed first): Common yarrow, Goldenrods, White snakeroot, Chicory, Black-eyed Susan, Bull thistle, Common dandelion, Firewheel.

More Texas flowers

Firewheel

Gaillardia pulchella

★ OK state wildflowerNative

🌼 Blooms in TX: April–June

Straggler daisy

Calyptocarpus vialis

🌼 Blooms in TX: April–May

Upright prairie coneflower

Ratibida columnifera

Native

🌼 Blooms in TX: April–June

Sources

USDA, NRCS. PLANTS Database, profile HEMA2.
iNaturalist, Helianthus maximiliani: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Helianthus maximiliani (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)).
Oklahoma: Oklahoma Noxious Weed Law (2 O.S. § 3-220).
Kansas: Kansas noxious weeds (K.A.R. 4-8-44, as amended 2026).
South Dakota: South Dakota statewide noxious weeds (ARSD 12:62:03:01.06).
Nebraska: Nebraska threatened and endangered species (163 Neb. Admin. Code ch. 4, § 004).
Nebraska: Nebraska noxious weeds (25 Neb. Admin. Code ch. 10, § 001.02).
North Dakota: North Dakota state noxious weeds (N.D. Admin. Code 7-06-01-02), as listed by the ND Department of Agriculture.
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Helianthus maximiliani (global and state ranks).
Edibility and toxicity: NC State Extension; ASPCA.
Photo: Michelle W. （鍾偉瑋） via iNaturalist · CC BY 4.0 · resized.