Flower profile

Green comet milkweed

Asclepias viridiflora

Green comet milkweed (Asclepias viridiflora) is a flowering plant in the Apocynaceae family, native in the lower 48 states, blooming mostly June–August across the U.S.

Native in the lower 48

Green comet milkweed is a wildflower that USDA PLANTS lists as native 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 June–August.

37states where USDA records it

2Bloomipedia state lists include it

11,664U.S. sightings*

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

On our lists for: North Dakota, Oklahoma

Quick look

Asclepias viridiflora; also known as green comet milkweed, green-flower milkweed, and green milkweed; is a species of milkweed (Asclepias). The plant is located in the eastern and central United States, ranging between Connecticut to Georgia and Arizona to Montana, and is also in southern Canada and northern Mexico. The Latin epithet viridiflora translates as "green-flowered".
From Wikipedia's article Asclepias viridiflora, CC BY-SA 4.0.

It belongs to the Apocynaceae 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 Oklahoma and North Dakota. ^NatureServe
iNaturalist has 554 research-grade sightings of it in Oklahoma, ranking #60 among the 159 flowers on our Oklahoma list. ^iNaturalist
iNaturalist has 156 research-grade sightings of it in North Dakota, ranking #41 among the 116 flowers on our North Dakota list. ^iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (1,040 records)

Bloom time in the 2 states whose Bloomipedia list includes it

State	Type	Peak bloom	Sightings*
Oklahoma	Native	few records (24)	554
North Dakota	Native	few records (11)	156

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
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.
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: Other states where NatureServe ranks it rare or missing: AZ (S1), CT (S1), FL (S1), NJ (S2), NY (S2), WV (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 peoplePoisonous to people

NC State Extension lists it as poisonous to humans (severity: low). Poisonous parts: flowers, fruits, leaves, sap/juice, stems. Symptoms they list: “Can cause stomach upset, nausea, vomiting, abdominal pain, diarrhea, weakness, lethargy, and confusion if eaten in quantity. Milky sap can cause contact dermatitis and eye irritation.” ^{NC State Extension}

For petsToxic to dogs, cats and horses

ASPCA's entry “Milkweed” (Asclepias species), which covers the whole genus, lists it as toxic to dogs, cats and horses. Signs include: Vomiting, profound depression, weakness, anorexia, and diarrhea are common; may be followed by seizures, difficulty breathing, rapid, weak pulse, dilated pupils, kidney or liver failure, coma… ^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 green comet milkweed in 37 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, Arizona, Arkansas, Colorado, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, 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, West Virginia, Wisconsin, Wyoming; District of Columbia.

Oklahoma counties with USDA records: Beckham, Bryan, Carter, Cleveland, Comanche, Creek, Custer, Garfield, Grady, Greer, Johnston, Kingfisher, Kiowa, Le Flore, Logan, Love, Major, Marshall, Mayes, McClain, Murray, Muskogee, Oklahoma, Pawnee, Payne, Pontotoc, Roger Mills, Texas, Woods.

North Dakota counties with USDA records: Barnes, Benson, Billings, Burke, Burleigh, Dunn, Eddy, Emmons, Golden Valley, Grant, Kidder, McHenry, McKenzie, Mercer, Morton, Mountrail, Oliver, Pembina, Pierce, Ransom, Renville, Richland, Sargent, Sheridan, Sioux, Slope, Stark, Steele, Stutsman, Ward, Williams.

Names, range and relatives

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

Other scientific names (synonyms in USDA PLANTS): Acerates viridiflora.

County records: USDA PLANTS lists it in 882 counties across 36 states; the most are in Kansas (101), Missouri (71), Illinois (67).

Other Asclepias on Bloomipedia (16): Common milkweed, Butterfly milkweed, Swamp milkweed, Green antelopehorns, Antelopehorn milkweed, Showy milkweed, Narrowleaf milkweed, Zizotes milkweed, Tropical milkweed, Redring milkweed.

More from the Apocynaceae family (28 on Bloomipedia; most observed first): Lesser periwinkle, Greater periwinkle, Spreading dogbane, Pearl milkweed, Madagascar periwinkle, Honey-vine climbing milkweed, Hartweg's climbing milkweed, Oleander.

More Oklahoma flowers

Green antelopehorns

Asclepias viridis

Native

🌼 Blooms in OK: April–June

Butterfly milkweed

Asclepias tuberosa

Native

🌼 Blooms in OK: May–June

Honey-vine climbing milkweed

Cynanchum laeve

Native

🌼 Few flowering records in OK

Sources

USDA, NRCS. PLANTS Database, profile ASVI.
iNaturalist, Asclepias viridiflora: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Asclepias viridiflora (lead quoted under CC BY-SA 4.0).
Oklahoma: Oklahoma Noxious Weed Law (2 O.S. § 3-220).
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, Asclepias viridiflora (global and state ranks).
Edibility and toxicity: NC State Extension; ASPCA.
Photo: ashleyrsteel via iNaturalist · CC BY 4.0 · resized.