Bloomipedia
Mountain woodsorrel (Oxalis montana)
Photo: Laura J. Costello via iNaturalist · CC BY 4.0 · resized

Flower profile

Mountain woodsorrel

Oxalis montana

Mountain woodsorrel (Oxalis montana) is a flowering plant in the Oxalidaceae family, native in the lower 48 states, blooming mostly June–July across the U.S.

Native in the lower 48

Mountain woodsorrel 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 June–July.

20states where USDA records it
3Bloomipedia state lists include it
8,923U.S. sightings*

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

On our lists for: Maine, New Hampshire, Vermont

Quick look

Oxalis montana is a species of flowering plant in the family Oxalidaceae known by the common names mountain woodsorrel, wood shamrock, sours and white woodsorrel. It may also be called common woodsorrel, though this name also applies to its close relative, Oxalis acetosella.

  • It belongs to the Oxalidaceae 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 20 states. USDA PLANTS
  • NatureServe lists it as native to Vermont, New Hampshire and Maine. NatureServe
  • In Vermont, most iNaturalist sightings of it in flower come in June–July. iNaturalist
  • In New Hampshire, most iNaturalist sightings of it in flower come in June–July. iNaturalist
  • iNaturalist has 1,586 research-grade sightings of it in Vermont, ranking #50 among the 159 flowers on our Vermont list. iNaturalist
  • iNaturalist has 1,577 research-grade sightings of it in New Hampshire, ranking #32 among the 157 flowers on our New Hampshire list. iNaturalist
  • iNaturalist has 836 research-grade sightings of it in Maine, ranking #90 among the 160 flowers on our Maine list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (1,322 records)
Bloom time in the 3 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
VermontNativeJune–July1,586
New HampshireNativeJune–July1,577
MaineNativeJune–July836

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
Vermont
Not listed Not on Endangered and Threatened Plants of Vermont (10 V.S.A. chap. 123; list of Feb 10, 2022). NatureServe: S5, secure in Vermont. Vermont E&T list
New Hampshire
Not listed Not on New Hampshire Official Rare Plants List (Ncr 312, eff. Jan 1, 2020). NatureServe: SNR, not yet ranked in New Hampshire. NH Ncr 312
Maine
Not listed Not on Maine Rare Plant List (Maine Natural Areas Program, 2021). E and T are Maine's official endangered and threatened plants (12 M.R.S.); SC and PE are tracking categories. NatureServe: SNR, not yet ranked in Maine. Maine rare plant list
Rare elsewhere
Other states where NatureServe ranks it rare or missing: GA (SH), OH (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 peopleCaution: partly edible, partly poisonous

NC State Extension lists it as poisonous to humans (severity: low). Poisonous parts: bark, flowers, fruits, leaves, roots, sap/juice, seeds, stems. Symptoms they list: “The leaves contain oxalic acid that, taken in large amounts, can bind up the body's supply of calcium leading to nutritional deficiency. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution since it…” They also note: “Small amounts of leaves, flowers, seeds, tubers/roots can be eaten raw are not dangerous they lend a sour taste to drinks and salads, hence the common name Sourwood.” NC State Extension

For petsToxic to dogs, cats and horses

ASPCA's entry “Good Luck Plant” (Oxalis spp), which covers the whole genus, lists it as toxic to dogs, cats and horses. 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 mountain woodsorrel in 20 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Connecticut, Georgia, Indiana, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Vermont, Virginia, West Virginia, Wisconsin.

Vermont counties with USDA records: Addison, Bennington, Caledonia, Chittenden, Essex, Franklin, Lamoille, Orange, Orleans, Rutland, Washington, Windham, Windsor.

New Hampshire counties with USDA records: Belknap, Carroll, Cheshire, Coos, Grafton, Hillsborough, Merrimack, Strafford, Sullivan.

Maine counties with USDA records: Androscoggin, Aroostook, Cumberland, Franklin, Hancock, Kennebec, Knox, Lincoln, Oxford, Penobscot, Piscataquis, Somerset, Waldo, Washington, York.

Names, range and relatives

Native status by region (USDA PLANTS): Canada: Native; Lower 48 states: Native; St. Pierre and Miquelon: Native.

County records: USDA PLANTS lists it in 232 counties across 17 states; the most are in Pennsylvania (41), New York (30), Michigan (23).

Other Oxalis on Bloomipedia (5): Bermuda buttercup, Violet woodsorrel, Largeflower pink-sorrel, Redwood sorrel, Oregon woodsorrel.

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Sources