Bloomipedia
Spotted lady's thumb (Persicaria maculosa)
Photo: Barrett Coller Jr. via iNaturalist · CC BY 4.0 · resized

Flower profile

Spotted lady's thumb

Persicaria maculosa

Spotted lady's thumb (Persicaria maculosa) is a flowering plant in the Polygonaceae family, introduced in the lower 48 states, blooming mostly July–October across the U.S.

Not native to Iowa

Spotted lady's thumb is a wildflower that USDA PLANTS lists as introduced in the lower 48 states.

49states where USDA records it
293IA sightings*
8,700U.S. sightings*

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

On our lists for: Iowa

Quick look

Persicaria maculosa is an annual plant in the buckwheat family, Polygonaceae. Common names include lady's thumb, spotted lady's thumb, Jesusplant, and redshank. It is widespread across Eurasia from Iceland south to Portugal and east to Japan.

  • It belongs to the Polygonaceae family. iNaturalist
  • USDA PLANTS describes it as an herb (forb) with a annual, perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as introduced in the lower 48 states and records it in 49 states. USDA PLANTS
  • NatureServe lists it as not native to Iowa. NatureServe
  • USDA PLANTS lists its flower color as red. USDA PLANTS
  • USDA PLANTS gives its bloom period as spring. USDA PLANTS
  • USDA PLANTS lists a mature height of about 3.2 ft. USDA PLANTS
  • iNaturalist has 293 research-grade sightings of it in Iowa, ranking #88 among the 147 flowers on our Iowa list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (558 records)

There are only a handful of Iowa flowering records, so this chart uses records from across the U.S.

Conservation status

Federal (U.S. ESA)
Not listed Not listed under the Endangered Species Act. USFWS ECOS does track it with the label “Resolved Taxon,” which is informal and gives no legal protection. USFWS ECOS
NatureServe global
G4 Apparently secure worldwide. NatureServe
Iowa
Not listed Not on Iowa endangered, threatened and special concern plants (Iowa Admin. Code r. 571-77.3). NatureServe: SNA, not applicable (usually because it isn't native there) in Iowa. IAC 571-77.3
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 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 spotted lady's thumb in 49 states plus Washington, D.C.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming; District of Columbia.

Iowa counties with USDA records: Adair, Adams, Allamakee, Audubon, Cass, Cherokee, Crawford, Fremont, Greene, Guthrie, Harrison, Ida, Madison, Mills, Monona, Montgomery, O'Brien, Osceola, Page, Plymouth, Pottawattamie, Ringgold, Shelby, Sioux, Taylor, Union, Webster, Winneshiek, Woodbury.

Growing conditions

USDA PLANTS gives Spotted lady's thumb a high shade tolerance, medium drought tolerance and medium moisture use. It is rated for soil pH 4.0 to 8.5 and winter lows down to 32 °F.

Shade tolerance
High
Drought tolerance
Medium
Moisture use
Medium
Soil textures it is adapted to
coarse, medium, fine
Soil pH range
4.0 to 8.5
Minimum temperature tolerated
32 °F
Frost-free days needed (minimum)
110
Annual precipitation range
14 to 60 inches
Minimum root depth
14 inches
Salinity tolerance
Low
Fertility requirement
Low
Growth rate
Rapid
Lifespan
Short
Active growth period
Spring
Fruit or seed
Black · Spring to Fall
Can be propagated by
seed
Commercial availability
Routinely Available

From the USDA PLANTS characteristics data for POPE3. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

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

Other scientific names (synonyms in USDA PLANTS): Persicaria maculata, Persicaria persicaria, Persicaria puritanorum, Persicaria ruderalis, Persicaria vulgaris, Polygonum dubium, Polygonum fusiforme, Polygonum puritanorum.

County records: USDA PLANTS lists it in 1447 counties across 49 states; the most are in Virginia (91), Illinois (88), North Carolina (88).

Other Persicaria on Bloomipedia (5): American jumpseed, Low smartweed, Mile-a-minute weed, Water smartweed, Pink knotweed.

More from the Polygonaceae family (21 on Bloomipedia; most observed first): California buckwheat, Japanese knotweed, Sulfur buckwheat, Desert trumpet, American bistort, Cushion buckwheat, Devil's spineflower, Parsnipflower buckwheat.

More Iowa flowers

American jumpseed (Persicaria virginiana)

American jumpseed

Persicaria virginiana

Native

🌼 Few flowering records in IA
Low smartweed (Persicaria longiseta)

Low smartweed

Persicaria longiseta

Introduced

🌼 Few flowering records in IA
Common milkweed (Asclepias syriaca)

Common milkweed

Asclepias syriaca

Native

🌼 Blooms in IA: June–July

Sources