Bloomipedia
Hooker's onion (Allium acuminatum)
Photo: Don Loarie via iNaturalist · CC BY 4.0 · resized

Flower profile

Hooker's onion

Allium acuminatum

Hooker's onion (Allium acuminatum) is a flowering plant in the Amaryllidaceae family, native in the lower 48 states, blooming mostly May–July across the U.S.

Native in the lower 48

Hooker's onion 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 May–July.

11states where USDA records it
2Bloomipedia state lists include it
4,379U.S. sightings*

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

On our lists for: Idaho, Utah

Quick look

Allium acuminatum, also known as the tapertip onion or Hooker's onion, is a species in the genus Allium native to North America.

  • It belongs to the Amaryllidaceae 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 11 states. USDA PLANTS
  • NatureServe lists it as native to Utah and Idaho. NatureServe
  • In Utah, most iNaturalist sightings of it in flower come in May–June. iNaturalist
  • In Idaho, most iNaturalist sightings of it in flower come in May–July. iNaturalist
  • USDA PLANTS lists its flower color as purple. USDA PLANTS
  • USDA PLANTS gives its bloom period as summer. USDA PLANTS
  • USDA PLANTS lists a mature height of about 1 ft. USDA PLANTS
  • iNaturalist has 943 research-grade sightings of it in Utah, ranking #61 among the 153 flowers on our Utah list. iNaturalist
  • iNaturalist has 626 research-grade sightings of it in Idaho, ranking #45 among the 143 flowers on our Idaho list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (1,044 records)
Bloom time in the 2 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
UtahNativeMay–June943
IdahoNativeMay–July626

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
Utah
No list Utah has no state law listing endangered or threatened plants, so we show NatureServe's Utah ranks instead. NatureServe: SNR, not yet ranked in Utah.
Idaho
No list Idaho has no state law listing endangered or threatened plants, so we show NatureServe's Idaho ranks instead. NatureServe: SNR, not yet ranked in Idaho.
Rare elsewhere
Other states where NatureServe ranks it rare or missing: MT (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 page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list. For context only: ASPCA lists a related species, Allium ampeloprasum (“Leek”), as 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 hooker's onion in 11 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming.

Utah counties with USDA records: Beaver, Box Elder, Cache, Daggett, Davis, Duchesne, Garfield, Grand, Iron, Juab, Millard, Morgan, Rich, Salt Lake, San Juan, Sanpete, Sevier, Summit, Tooele, Uintah, Utah, Wasatch, Washington, Weber.

Idaho counties with USDA records: Ada, Adams, Bannock, Bear Lake, Bingham, Blaine, Boise, Butte, Camas, Canyon, Cassia, Clark, Custer, Elmore, Franklin, Fremont, Gem, Gooding, Idaho, Kootenai, Latah, Lemhi, Lincoln, Nez Perce, Oneida, Owyhee, Payette, Power, Twin Falls, Valley, Washington.

Growing conditions

USDA PLANTS gives Hooker's onion a high shade tolerance, medium drought tolerance and low moisture use. It is rated for soil pH 6.0 to 8.0 and winter lows down to -28 °F.

Shade tolerance
High
Drought tolerance
Medium
Moisture use
Low
Soil textures it is adapted to
coarse, medium
Soil pH range
6.0 to 8.0
Minimum temperature tolerated
-28 °F
Frost-free days needed (minimum)
120
Annual precipitation range
10 to 60 inches
Minimum root depth
6 inches
Salinity tolerance
None
Fertility requirement
Low
Growth rate
Rapid
Lifespan
Short
Active growth period
Spring and Summer
Fruit or seed
Black · Summer to Fall
Can be propagated by
bulb, container, seed
Commercial availability
Contracting Only

From the USDA PLANTS characteristics data for ALAC4. 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.

County records: USDA PLANTS lists it in 154 counties across 11 states; the most are in Idaho (31), Oregon (28), Utah (24).

Other Allium on Bloomipedia (6): Wild garlic, Wide leek, Nodding onion, Textile onion, Prairie onion, Shortstyle onion.

More from the Amaryllidaceae family (13 on Bloomipedia; most observed first): Crowpoison, Drummond's rain lily, Brazos rain-lily, Red spider lily, Southern swamp crinum, Atamasco lily, Daffodil.

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Sources