Preview. This site is being tested before the printed calendar is finished, and pages may still change. See the calendar (preview PDF)

A Forager’s Year

No. 110

Dock

Rumex crispus, R. obtusifolius

curly dock, broadleaf dock

Nut & seed dry brown seeds in their papery husks (toasted and ground into flour)

Drawing: Britton & Brown, Illustrated Flora (1913)

Sources disagree. A University of Colorado Boulder ecologist writes that oxalate levels rise as curly dock seeds mature, making them bitter and toxic, while foraging sources grind the mature seeds into flour; no source measures the oxalate in the seeds or reports anyone made ill by eating them.

Find
Common in the right habitat
Effort
Quick kitchen prep
ID risk
Beginner
Origin
non-native ★
Safety marks
  • Spray risk
Uses
  • Baking & desserts
  • Flour

Season

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec

in season peak

Picking: The rules are unclear. Ask the park. See Where you may pick.

What these mean

Find

1 Everywhere · 2 Common in the right habitat · 3 Patchy · 4 Elusive. This is about how much there is, not whether you may pick it. It is based on iNaturalist sightings within 25 km (about 15 miles) of downtown DC, counted on October 3, 2026. The four rules that each plant’s “Find” reason refers to: (A) the estimate is the confirmed sightings, plus the unconfirmed ones (scaled down where the plant has lookalikes in its genus), plus the sightings marked as planted; (B) the tier by estimate: 1,500 or more is tier 1, 250–1,499 tier 2, 50–249 tier 3, under 50 tier 4; (C) tier 1, Everywhere, also needs a source saying the plant is common in lawns, sidewalks, yards or gardens, vacant lots or towns, or at least one DC street tree of it per km of sidewalk, otherwise it is tier 2; (D) if a reliable source says the plant is rare in this region, or that wild plants rarely bear the harvest, only planted sightings count. iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Effort

1 Grab & eat · 2 Quick kitchen prep (under about 30 minutes) · 3 Real work (hours, or cooking needed for safety) · 4 Project (days or equipment). Scored on the simplest worthwhile use; each plant’s page says why.

ID risk

How hard it is to harvest safely. Beginner: no dangerous lookalike, and the edible part is not easily confused with a toxic part. Careful: a toxic lookalike, or toxic parts that end up in the harvest unless removed (for example elderberry stems, unripe ground cherries), or other parts of the plant rated medium-or-higher toxicity, with reliable features to separate them. Expert only: a potentially deadly lookalike that is hard to separate, or (for not-recommended harvests like pokeweed) a plant whose safe preparation can’t be guaranteed. Toxic parts that are obviously separate and thrown away anyway (pits, seeds, skins) don’t raise it; the Toxic parts mark carries that warning.

Native or not, and the invader stars

Origin is where the plant comes from: native, non-native, or mixed (the harvest covers both). The stars rate plants on invasive plant lists: ★★★ Virginia DCR “High” or Maryland prohibited invasive · ★★ Virginia “Medium” · ★ Virginia “Low” · ☆ listed only by the Maryland Invasive Species Council or the Mid-Atlantic Plant Invaders guide (advisory) · no stars: native or not listed.

Safety marks and flags

Deadly lookalike / Toxic lookalike: a cited source names a lookalike of that danger, recorded near DC (an iNaturalist sighting within 25 km, a DC street tree, or a Smithsonian listing for DC) and looking like the part you eat. Other lookalikes are still listed, marked “not recorded near DC” or as not looking like the part you eat. Deadly means a source says eating it may be fatal or calls it deadly, or NC State rates it high severity with life-threatening symptoms (sources sometimes disagree; for example Virginia creeper). Each plant’s Lookalikes list says how to tell them apart; “harmless (may be edible)” lookalikes are listed so you know a mix-up isn’t dangerous. Cook first: cooking is needed for safety (for daylilies it is a precaution, not a sourced requirement). Eat in moderation: a source says to limit quantity or frequency (for example oxalates in sorrels and dock, ginkgotoxin, safrole). Spray risk: a source says the plant is commonly treated with herbicide in parks or lawns (invasive control, lawn weeds) or, for ginkgo, sprayed to stop fruiting. Contamination: a source says the plant concentrates pollutants. Each plant’s Safety flags list gives the details and sources.

Seasons

Start, peak and end are given in thirds of a month: early, mid or late. A plant counts as in season for a month if it is in season at any point in that month. Some greens and roots have a second window, in spring or fall; their page shows each window. A season that runs across New Year is shown as one window.

What it looks like

The seeds of curly dock and broadleaf (bitter) dock, weedy perennials of the buckwheat family. After flowering, curly dock’s stalks, up to 3 feet tall, carry large, branching clusters of seeds (University of Maryland Extension; Utah State University); the greenish flowers turn reddish brown as they mature, and the stalks stand through winter (Fairfax County Master Gardeners; University of Maryland Extension). Each flower makes one glossy, three-sided seed, reddish brown and 2 to 3 mm long, wrapped in three papery, heart-shaped wings that usually carry a small wart-like thickening, called a grain (Utah State University; Minnesota Wildflowers). Broadleaf (bitter) dock, gathered the same way, has broader leaves with heart-shaped bases and seed wings with a few large teeth (Washington State University; Minnesota Wildflowers); its seeds are ground and added to flour or meal for bread, muffins and gravies (Robin Harford, Eat Weeds). Backyard Forager says both curly and broadleaf dock are edible at several stages. Separating the seeds from the papery husks is hard, so Practical Self Reliance advises grinding seed and husk together. Dock is related to buckwheat, and its seeds taste a bit like buckwheat but with quite a bit of bitterness (Practical Self Reliance). Eat The Weeds says dock seeds can be cooked and eaten but are not high on the foraging list.

Safety

NC State lists curly dock as poisonous to people at low severity, from soluble calcium oxalates, and does not exempt any part of the plant. A University of Colorado Boulder ecologist writes that oxalate levels rise as the leaves and seeds mature, making them bitter and toxic, and that the oxalates in leaves and seeds are toxic to poultry; Utah State University also says the seeds are toxic to poultry. No source measures the oxalate in the seeds or reports anyone made ill by eating them, so use dock seed flour as a small part of a flour mix rather than on its own. A 2025 scientific review (Food Science & Nutrition) says people with kidney stones, gout, arthritis, rheumatism or hyperacidity should avoid eating dock, and lists a fatal oxalate poisoning after a large amount of curly dock was eaten (Veterinary and Human Toxicology, 1990). Dock also contains anthraquinones, which act as a mild laxative (Utah State University). Broadleaf (bitter) dock seeds are gathered and used the same way; the 2025 review says broadleaf dock is not recommended as food because of skin and stomach irritation, and that handling its leaves can cause a skin rash. Robin Harford, a foraging author, says broadleaf dock contains oxalic acid, which can be toxic if eaten to excess, that some writers advise avoiding it during pregnancy and breastfeeding, and that it can trigger hay fever or aggravate asthma in some people; no safety source checked confirms the last two points. University of Maryland Extension recommends spot-treating dock in lawns with broadleaf weed killers, so avoid lawns and turf that may have been sprayed.

Safety flags

Safety marks and flags: what this means

Deadly lookalike / Toxic lookalike: a cited source names a lookalike of that danger, recorded near DC (an iNaturalist sighting within 25 km, a DC street tree, or a Smithsonian listing for DC) and looking like the part you eat. Other lookalikes are still listed, marked “not recorded near DC” or as not looking like the part you eat. Deadly means a source says eating it may be fatal or calls it deadly, or NC State rates it high severity with life-threatening symptoms (sources sometimes disagree; for example Virginia creeper). Each plant’s Lookalikes list says how to tell them apart; “harmless (may be edible)” lookalikes are listed so you know a mix-up isn’t dangerous. Cook first: cooking is needed for safety (for daylilies it is a precaution, not a sourced requirement). Eat in moderation: a source says to limit quantity or frequency (for example oxalates in sorrels and dock, ginkgotoxin, safrole). Spray risk: a source says the plant is commonly treated with herbicide in parks or lawns (invasive control, lawn weeds) or, for ginkgo, sprayed to stop fruiting. Contamination: a source says the plant concentrates pollutants. Each plant’s Safety flags list gives the details and sources.

ID risk
Beginner
Why
No toxic lookalike is named. Curly dock and broadleaf dock seeds are gathered and used the same way; other docks are not named as dangerous in the sources.
Handling hazards
Irritant sap/pulp (moderate)
Soil risk
low
ID risk: what this means

How hard it is to harvest safely. Beginner: no dangerous lookalike, and the edible part is not easily confused with a toxic part. Careful: a toxic lookalike, or toxic parts that end up in the harvest unless removed (for example elderberry stems, unripe ground cherries), or other parts of the plant rated medium-or-higher toxicity, with reliable features to separate them. Expert only: a potentially deadly lookalike that is hard to separate, or (for not-recommended harvests like pokeweed) a plant whose safe preparation can’t be guaranteed. Toxic parts that are obviously separate and thrown away anyway (pits, seeds, skins) don’t raise it; the Toxic parts mark carries that warning.

Handling hazards: what this means

Stings, thorns, irritating or phototoxic sap, staining hulls and spiny husks, with a severity: minor = brief discomfort; moderate = rash or blisters lasting days; serious = burns, scarring or medical care possible.

Soil risk: what this means

Based on the part you eat, following the urban-soil lead guidance on the Field safety page: higher for greens, shoots and roots; moderate for flowers; low for fruit, nuts and sap.

Field safety for every outing (poison ivy, ticks, soil, and more)

When to pick

Starts
early Jul
Peak
early Aug–late Sep
Ends
mid Mar

Curly dock flowers from April through July, and the flowers turn reddish brown as the seeds mature (Virginia Tech; Fairfax County Master Gardeners). In the DC area, iNaturalist sightings of curly and broadleaf dock marked as fruiting run from late April into September, with one in December. Gather the seeds once they are brown and dry on the stalk; Practical Self Reliance says they can be picked green but taste much better dried. The brown stalks stand through winter (University of Maryland Extension), and in Vermont seeds still cling to them until the new spring leaves sprout (Practical Self Reliance). Utah State University says the seeds are shed steadily from late summer through the winter, so the heads thin out as the season goes on.

How the dates were worked out

Every start, peak and end was re-checked in October 2026. “Sourced” means a source opened during the check states that timing for the DC or Mid-Atlantic area. “Estimated” means no source states it exactly; the reason, the evidence and the source links are under “How the dates were worked out” on each plant’s page. Peaks are often estimated, because few sources name a peak. iNaturalist evidence means research-grade sightings near DC, by month, of the plant at that stage (for example, in fruit). iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Season basis: estimated: start, peak, end

Start

estimated: No source dates when the seeds turn brown in the DC area. Early July is an estimate: fruit is logged from late April, and seed heads from the April to July flowering turn reddish brown as they mature; brown, dry seed for flour follows the green fruit.

Peak

estimated: No source names a peak. August and September follow the main April to July flowering, when most seed heads have turned brown, and come before the steady shedding through fall and winter thins the heads.

End

estimated: No DC-area source dates the end. Mid March keeps the late-winter tail that Practical Self Reliance describes, ending as new dock leaves come up in early March around DC; by then many seeds have been shed (Utah State University).

Evidence

start: Virginia Tech: 'flowering from April through July'. Fairfax County Master Gardeners: 'Flowers appear April-July and continue thru late Fall, turning reddish-brown at maturity.' DC iNaturalist research-grade sightings of curly and broadleaf dock annotated as fruiting: 27 (April 1, May 5, June 11, July 6, August 2, September 1, December 1; earliest April 27). Backyard Forager: 'By early summer, dock produces tall flower stalks that bear copious amounts of seed'. Practical Self Reliance: 'You can harvest them when they are green but it is my understanding that the flavor is much better once they have dried on the stalk.' | peak: Fairfax County Master Gardeners: flowers 'continue thru late Fall, turning reddish-brown at maturity.' Utah State University: 'The seeds are shed continuously from late summer through the winter.' | end: University of Maryland Extension: flowering stalks 'turning rusty brown, persisting through winter'. Practical Self Reliance (Vermont): 'The seed stalks persist through the winter months' and 'dock seeds persist all the way until spring greens sprout'. Utah State University: 'The seeds are shed continuously from late summer through the winter.'

Where to look

Fields, pastures, vacant lots and weedy meadows, wherever tall brown seed stalks are left unmowed; it is logged most along the Mount Vernon Trail, in Rock Creek Park and along Four Mile Run, where picking is not allowed. The C&O Canal and Virginia state parks may or may not count dock seeds as allowed fruits or nuts (ask the park first), so the sure option is private land with the owner’s permission, away from lawns that may be sprayed.

Habitats
disturbed ground & waste places, vacant lots, old fields & meadows, wetlands, marshes & pond edges
Habitats: what this means

Listed where the plant’s own sources place it in that habitat. “Disturbed ground & waste places” means a cited source places it on disturbed areas, sites, soil or ground, on waste places or waste ground, on construction or abandoned building sites (old home sites count), on rubble or in strip mines. When the source gives examples of the disturbed places, at least one example must be of that kind. Examples that do not count: natural or forestry disturbance (treefall gaps, fire, windthrow, flood scour, old riverbanks and creeks, clear-cuts); roadsides, railroads and rights-of-way; and abandoned fields, pastures and farmland, which are “Old fields & meadows”. “Vacant lots” only where a source says vacant or empty lots.

Most-logged places

None of the most-logged places allows picking.

No picking here (5 places)
  • Mount Vernon Trail

    40 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: GW Memorial Parkway sites (incl. Great Falls VA, Theodore Roosevelt Island, Dyke Marsh) designate nothing for gathering.

  • Rock Creek Park

    33 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Rock Creek Park’s compendium bans gathering any fruit, nut, berry, seed or greenery.

  • Four Mile Run stream valley (Arlington/Alexandria)

    26 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Arlington County park rules (flora shall not be removed or disturbed) and Alexandria’s permit rule both apply.

  • Glencarlyn Park

    20 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Arlington County park rules say flora shall not be removed or disturbed.

  • Huntley Meadows Park

    20 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Fairfax County parks ban removing any plant part without written permission.

Most-logged places: what this means

The places with the most research-grade iNaturalist sightings within 25 km of downtown DC (re-counted in October 2026 over every named place, campuses, condominiums and private grounds included), each marked legal to pick or not. A sighting inside several named places counts once, for the smallest of them, but a sighting inside a National Park Service park never counts for a private, campus or unchecked place. iNaturalist shows where people walk and log plants, not true abundance. Private campuses, condominiums, museums, estates and utility land (Pepco’s power-line land near Sligo Creek) are marked “no” (pick only with the owner’s permission); public university campuses, city parks and other places whose picking rules were not checked (county stormwater land, the U.S. Capitol Grounds, Greenbelt’s North Woods, federal facilities such as the National Zoo) are “unknown”. A place needs at least 2 sightings, so plants with very few sightings have no places. At-risk plants (butternut, nannyberry, American chestnut, ramps, riverbank goldenrod) get places like every other plant; each page says why the plant is at risk and gives any advice its sources give. For some places, mostly Rock Creek Park, the iNaturalist map shows more sightings than the count here, because a map link cannot leave out exactly the sightings credited to another place. iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Ways to use it

  • toasted in the oven for about 8 to 10 minutes, cooled and ground into flour, husks and all (Practical Self Reliance)
  • flour used for up to about a quarter of the flour in a recipe, best in heavy-textured baking such as crackers or brownies, since it has no gluten (Practical Self Reliance)
  • boiled into a mush (broadleaf dock; Robin Harford, Eat Weeds)
  • crackers: lightly toasted, ground seed cooked into a paste with starch, water and oil, spread thin and baked until crisp (Eat Weeds, Robin Harford)
  • harvest dry seed by stripping it from the stalks; in a good patch several cups take only a few minutes (Practical Self Reliance)

Keeping

The seeds stay on the stalk into winter, so gather as needed, and keep the seeds or flour airtight in a cool, dark place for 4 months to a year.

Use within
months+
Keeps fresh
The seeds dry on the stalk, and the stalks stand through winter (University of Maryland Extension), so gather as needed. Once gathered, keep the seeds or flour like other dried foods, in clean, dry, insect-proof containers in a cool, dry, dark place (general guidance for dried foods; NCHFP).
Keeping basis
general guidance for its type

Ways to keep it

  • Dry as researched: dry/dehydrate; canning: n/a (not shelf-canned)

    Toast the seeds in the oven for 8 to 10 minutes so they are dry enough to grind, and let them cool completely before grinding (Practical Self Reliance). NCHFP: dried foods should be stored in cool, dry, dark areas, and recommended storage times range from 4 months to 1 year, shorter at higher temperatures. Robin Harford says baked dock seed crackers stay fresh for weeks in an airtight container in a cool, dry place.

Canning: what this means

Shelf-stable canning, three levels. Lab-tested: a lab-tested recipe from the National Center for Home Food Preservation (NCHFP) or Oregon State covers this fruit and product, or a generic recipe for its kind (the line says so, for example chokeberry). Extension recipe: a published Extension recipe (University of Alaska Fairbanks, written for Alaska species; University of Maine’s dandelion jelly), or a process that is safe only with a pH meter; follow it exactly, never improvise. No tested recipe: refrigerate or freeze, don’t can. “Hot-bottled syrup” = maple and walnut syrup, which keep when bottled hot at full syrup density. The Canning line names the exact product each source covers, for example “whole berries” or “juice”; a product not named there (such as juice from a berry with only a whole-berry recipe) has no tested recipe.

Keeping basis: what this means

“Specific to this plant” or “general guidance for its type” (for example NCHFP guidance for leafy greens applied to a wild green).

Nutrition

Not researched: in October 2026, only the calendar’s plants of the month and chicory leaves were researched.

Native or not

VA DCR lists it as 'Rumex crispus ssp. crispus' (the widespread weedy subspecies). Broadleaf dock (R. obtusifolius), also introduced, is on none of the lists.

Origin
non-native
Native range
Eurasia & Africa
Invader credit
★
Virginia invasive rank
Low
Maryland invasive status
not listed
Native or not, and the invader stars: what this means

Origin is where the plant comes from: native, non-native, or mixed (the harvest covers both). The stars rate plants on invasive plant lists: ★★★ Virginia DCR “High” or Maryland prohibited invasive · ★★ Virginia “Medium” · ★ Virginia “Low” · ☆ listed only by the Maryland Invasive Species Council or the Mid-Atlantic Plant Invaders guide (advisory) · no stars: native or not listed.

Virginia DCR, Virginia Invasive Plant Species List (effective September 2024), verbatim: "Under the DCR Invasive Species Assessment Protocol, approved by the Virginia Invasive Species Working Group, January 2024, species were ranked as exhibiting high, medium or low levels of invasiveness based on their threat to natural communities and native species. Invasiveness rank is higher for species that: • Alter ecosystem processes, such as succession, hydrology or fire regime. • Are capable of invading undisturbed natural communities. • Cause substantial impacts on rare or vulnerable species or natural communities or high-quality examples of more common communities. • Are found widely distributed and generally abundant where present. • Disperse readily to new areas. • Are difficult to control." The list also states: "The list is for educational purposes only and has no regulatory authority."

Maryland Department of Agriculture, Maryland Prohibited Invasive Plant Law and Regulations page, verbatim: "Plants on the Maryland Prohibited Invasive Plant List may not be added to stock after the effective date and should not be sold after their phase-out period ends."

No official DC invasive plant list was found.

How the ratings were set

Find
Common in the right habitat Estimate 2,555 = 930 research-grade iNaturalist sightings within 25 km + 1,778 needs-ID sightings counted at 90% (930 of the 1,030 research-grade Rumex sightings here are curly dock or broadleaf dock) + 20 'cultivated' (planted) sightings (rule A); that is tier 1 by count (rule B). Rule C: none of its sources says it is common in, or a weed of, an everyday place (lawns, sidewalks, yards or gardens, vacant lots, towns), so it cannot be tier 1 (Everywhere). Final tier 2.
Effort
Quick kitchen prep Strip the dry seeds and husks from the stalks, toast them in the oven for 8 to 10 minutes, let them cool and grind them into flour; separating the seeds from the papery husks is slow and usually skipped (Practical Self Reliance).
Find: what this means

1 Everywhere · 2 Common in the right habitat · 3 Patchy · 4 Elusive. This is about how much there is, not whether you may pick it. It is based on iNaturalist sightings within 25 km (about 15 miles) of downtown DC, counted on October 3, 2026. The four rules that each plant’s “Find” reason refers to: (A) the estimate is the confirmed sightings, plus the unconfirmed ones (scaled down where the plant has lookalikes in its genus), plus the sightings marked as planted; (B) the tier by estimate: 1,500 or more is tier 1, 250–1,499 tier 2, 50–249 tier 3, under 50 tier 4; (C) tier 1, Everywhere, also needs a source saying the plant is common in lawns, sidewalks, yards or gardens, vacant lots or towns, or at least one DC street tree of it per km of sidewalk, otherwise it is tier 2; (D) if a reliable source says the plant is rare in this region, or that wild plants rarely bear the harvest, only planted sightings count. iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Effort: what this means

1 Grab & eat · 2 Quick kitchen prep (under about 30 minutes) · 3 Real work (hours, or cooking needed for safety) · 4 Project (days or equipment). Scored on the simplest worthwhile use; each plant’s page says why.

Sources

36 sources, each linked to the original.

  1. Rock Creek Park Superintendent’s Compendium National Park ServiceBacks up: picking rules
  2. 36 CFR 2.1 - Preservation of natural, cultural and archeological resources Legal Information Institute, Cornell Law School (text of federal regulation)Backs up: picking rules
  3. C&O Canal NHP Superintendent’s Compendium, effective September 11, 2026 National Park Service, Chesapeake and Ohio Canal NHPBacks up: picking rules
  4. 4VAC5-30-50. Flowers, plants, minerals, etc. Virginia Law Library (law.lis.virginia.gov)Backs up: picking rules
  5. Virginia Invasive Plant Species List (effective September 2024) Virginia Department of Conservation and RecreationBacks up: picking rules, native or invasive status
  6. Curly Dock (Rumex crispus) Minnesota WildflowersBacks up: description
  7. Rumex crispus (Curled Dock, Curly Dock, Yellow Dock) NC State Extension Gardener Plant ToolboxBacks up: description, safety, habitat, picking rules, native or invasive status
  8. Curly Dock (Steve’s weed of the month, February 2011) Washington State University Whitman County ExtensionBacks up: description, safety, effort & ID risk, safety details
  9. All About Dock (Members of the Genus Rumex) (Ellen Zachos) Backyard ForagerBacks up: description, season
  10. Dock University of Maryland ExtensionBacks up: description, season, safety, keeping
  11. Curly Dock (Range Plants of Utah) Utah State University ExtensionBacks up: description, season, safety, safety details
  12. The Traditional and Modern Uses of Broad-leaved dock (Rumex obtusifolius) Eat Weeds (Robin Harford)Backs up: description, uses, habitat, safety, effort & ID risk, safety details
  13. Foraging Dock Seeds ~ Wild Foraged Flour (A. Adamant, updated 2025) Practical Self RelianceBacks up: description, uses, season, storage, effort & ID risk, keeping
  14. Curly dock (wild blueberry weed images; D’Appollonio, updated 2018) University of Maine Cooperative ExtensionBacks up: description, effort & ID risk, safety details
  15. Rumex Ruminations (Green Deane) Eat The WeedsBacks up: description, safety details
  16. iNaturalist research-grade observations of Rumex crispus + R. obtusifolius within 25 km of downtown DC iNaturalistBacks up: findability
  17. Rumex crispus L. ssp. crispus (Curly Dock) (Digital Atlas of the Virginia Flora) Virginia Botanical Associates (Digital Atlas of the Virginia Flora)Backs up: habitat
  18. Rumex crispus (curly dock) Go Botany (Native Plant Trust)Backs up: habitat
  19. Curly Dock (TurfFiles weed profile) NC State ExtensionBacks up: habitat
  20. Checklist of the Vascular Plants of the Washington-Baltimore Area, part 1 (Shetler & Orli, 2000) Smithsonian Institution, National Museum of Natural HistoryBacks up: habitat
  21. Packaging and Storing Dried Foods National Center for Home Food Preservation (University of Georgia)Backs up: keeping
  22. USDA PLANTS Database: Rumex crispus (RUCR), native status USDA NRCSBacks up: native or invasive status
  23. USDA PLANTS Database: Rumex obtusifolius (RUOB), native status USDA NRCSBacks up: native or invasive status
  24. Maryland Prohibited Invasive Plant Law and Regulations (Maryland Prohibited Invasive Plant List, updated January 2026; additions effective July 15, 2026; 'Next Plants To Be Assessed' 2026-2027) Maryland Department of Agriculture, Plant Protection & Weed ManagementBacks up: native or invasive status
  25. Non-Native Invasive Terrestrial Plant Species in the State of Maryland (updates approved through the April 18, 2024 MISC meeting) Maryland Invasive Species CouncilBacks up: native or invasive status
  26. Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)Backs up: native or invasive status
  27. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
  28. Rumex Species: Phytochemistry, Pharmacology and Nutritional Potential for Food and Health Applications (Food Science & Nutrition, 2025) Food Science & Nutrition (Wiley), via PubMed CentralBacks up: safety, effort & ID risk, safety details
  29. Curly dock has all the traits of a super weed (J. Mitton, 2024) University of Colorado Boulder, Colorado Arts and Sciences MagazineBacks up: safety, safety details
  30. Fatal poisoning by Rumex crispus (curled dock): pathological findings and application of scanning electron microscopy (Reig and others, Veterinary and Human Toxicology, 1990), abstract PubMed (US National Library of Medicine)Backs up: safety, safety details
  31. Research-grade observations of curly dock (Rumex crispus) within 100 km of DC, by month (fruiting) iNaturalistBacks up: season
  32. Research-grade observations of curly dock and broadleaf dock (Rumex crispus, R. obtusifolius) within 25 km of DC, by month (fruiting) iNaturalistBacks up: season
  33. Research-grade observations of curly dock and broadleaf dock (Rumex crispus, R. obtusifolius) within 25 km of DC, by month (all observations) iNaturalistBacks up: season
  34. Curly Dock - Rumex crispus (broadleaf weeds fact sheet, 2021) Fairfax County Master Gardeners Association (Virginia)Backs up: season, description, habitat, safety details
  35. curly dock, Rumex crispus (weed profile) Virginia Tech Weed Identification (College of Agriculture and Life Sciences)Backs up: season, habitat, effort & ID risk, safety details
  36. Dock seed crackers (Robin Harford) Eat Weeds (Robin Harford)Backs up: uses, storage, effort & ID risk, keeping