Bloomipedia
Western Lily of the Valley (Maianthemum dilatatum)
Photo: John Brew via iNaturalist · CC BY 4.0 · resized

Flower profile

Western Lily of the Valley

Maianthemum dilatatum

Western Lily of the Valley (Maianthemum dilatatum) is a flowering plant in the Asparagaceae family, native in the lower 48 states, blooming mostly May–June across the U.S.

Native in the lower 48

Western Lily of the Valley is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 3 states, and across the U.S. it's most often seen in bloom in May–June.

5states where USDA records it
3Bloomipedia state lists include it
13,560U.S. sightings*

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

On our lists for: Alaska, Oregon, Washington

Quick look

Maianthemum dilatatum is a common rhizomatous perennial flowering plant that is native to western North America from northern California to the Aleutian Islands, and Asia across the Kamchatka Peninsula, Japan, and Korea. It grows in coastal temperate rainforests, and is often the dominant groundcover plant in Sitka Spruce forests.

  • It belongs to the Asparagaceae 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 5 states. USDA PLANTS
  • NatureServe lists it as native to Washington, Oregon and Alaska. NatureServe
  • In Washington, most iNaturalist sightings of it in flower come in May–June. iNaturalist
  • In Oregon, most iNaturalist sightings of it in flower come in May–June. iNaturalist
  • iNaturalist has 5,660 research-grade sightings of it in Washington, ranking #24 among the 187 flowers on our Washington list. iNaturalist
  • iNaturalist has 3,818 research-grade sightings of it in Oregon, ranking #39 among the 184 flowers on our Oregon list. iNaturalist
  • iNaturalist has 1,148 research-grade sightings of it in Alaska, ranking #37 among the 121 flowers on our Alaska list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (611 records)
Bloom time in the 3 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
WashingtonNativeMay–June5,660
OregonNativeMay–June3,818
AlaskaNativefew records (25)1,148

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
Washington
No list Washington has no state law listing endangered or threatened plants (the Washington Natural Heritage Program's rare plant list isn't regulatory), so we show NatureServe's Washington ranks instead. NatureServe: SNR, not yet ranked in Washington.
Oregon
Not listed Not on Oregon endangered and threatened plants (OAR 603-073-0070). NatureServe: SNR, not yet ranked in Oregon. OAR 603-073-0070
Alaska
No list Alaska has no state law listing endangered or threatened plants, so we show NatureServe's Alaska ranks instead. NatureServe: SNR, not yet ranked in Alaska.
Rare elsewhere
Other states where NatureServe ranks it rare or missing: ID (S1). (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.

🌿 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 Western Lily of the Valley in 5 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alaska, California, Idaho, Oregon, Washington.

Washington counties with USDA records: Chelan, Clallam, Cowlitz, Grays Harbor, Island, Jefferson, King, Kitsap, Kittitas, Klickitat, Lewis, Mason, Pacific, Pierce, San Juan, Skagit, Skamania, Snohomish, Thurston, Wahkiakum, Whatcom.

Oregon counties with USDA records: Benton, Clackamas, Clatsop, Columbia, Coos, Curry, Douglas, Lane, Lincoln, Linn, Marion, Multnomah, Polk, Tillamook, Washington, Yamhill.

Alaska counties with USDA records: Aleutians West, Anchorage, Chugach, Copper River, Haines, Juneau, Kenai Peninsula, Ketchikan Gateway, Kodiak Island, Sitka, Yakutat.

Names, range and relatives

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

Other scientific names (synonyms in USDA PLANTS): Maianthemum kamtschaticum.

County records: USDA PLANTS lists it in 57 counties across 5 states; the most are in Washington (21), Oregon (16), Alaska (11).

Other Maianthemum on Bloomipedia (3): Solomon's plume (false Solomon's seal), Canada mayflower, Star-flowered lily-of-the-valley.

More from the Asparagaceae family (34 on Bloomipedia; most observed first): Yuccas, Blue dicks, Common star-of-Bethlehem, Chaparral yucca, Mojave yucca, Wavy-leafed soap plant, Soaptree yucca, Western joshua tree.

More Washington flowers

Solomon's plume (false Solomon's seal) (Maianthemum racemosum)

Solomon's plume (false Solomon's seal)

Maianthemum racemosum

Native

🌼 Blooms in WA: April–June
Star-flowered lily-of-the-valley (Maianthemum stellatum)

Star-flowered lily-of-the-valley

Maianthemum stellatum

Native

🌼 Blooms in WA: May–July
Small camas (Camassia quamash)

Small camas

Camassia quamash

Native

🌼 Blooms in WA: April–May

Sources