Recognising wood sorrel and clover and using them sparingly
Wood sorrel and meadow clover both have three-part leaves and are easy to recognise. Wood sorrel tastes fresh and sour because it contains oxalic acid – so only a few leaves as seasoning, never a meal. Clover flowers and young clover leaves are mild, but are also meant only in small amounts. Here you learn the features, the look-alikes such as the poisonous wood anemone, and sensible amounts.
- Identifying and gathering 10–20 minutes
Explained simply
Wood sorrel and clover both have leaves made of three small leaflets. Wood sorrel grows in shady woods, its leaflets look like little hearts, and it tastes really sour – a bit like lemon. Clover grows in sunny meadows, has oval leaflets and round white or pink flower heads.
The sour taste comes from a substance called oxalic acid. In small amounts it is a fun, fresh taste. In large amounts, though, it is bad for the body, especially the kidneys. So you only eat a few leaflets as seasoning – never a whole bowl.
In spring a poisonous plant flowers white in the same woods: the wood anemone. But it has no heart-shaped leaflets; its leaves are deeply cut like a hand with many fingers. And as with all wild plants: only eat what you recognise for certain, and wash it well first.
How it works
Wood sorrel stores oxalic acid and its salts in its leaves. This protects the plant from being eaten and gives the typical sour taste. In the body oxalic acid combines with calcium to form poorly soluble crystals. In small amounts this is no problem; in large amounts it can take calcium away and strain the kidneys – up to poisoning.
Clover belongs to the legume family, like peas and beans. Its leaves contain protein but are hard to digest raw and can cause wind. White clover can contain cyanogenic glycosides in its leaves – substances from which small amounts of hydrogen cyanide can form when chewed. That is another reason why clover is eaten only in small amounts and the leaves are better cooked.
Both plants consist mostly of water and fibre. They provide hardly any energy and do not fill you up. Their value lies in the taste, a little variety and the fact that they are good for practising plant recognition.
What really matters
You recognise wood sorrel by three heart-shaped leaflets with their points towards the centre. At night, in rain and in strong sun they fold down like a little umbrella. It grows in shady woods, often as a dense carpet under spruce and beech. In April and May it bears single white flowers with five petals and fine purple veins.
Clover grows in the sun in meadows and lawns. Its three leaflets are oval, not heart-shaped, and often have a pale, V-shaped mark. The flowers stand together in round heads: white in white clover, pink to purple-red in red clover. The flower heads and a few young leaves are the best parts to gather.
The amount makes the difference. A small handful of wood sorrel leaves as seasoning for one person is enough, and not every day. Take clover in small amounts too, with the leaves briefly boiled or steamed. Everything is washed thoroughly with clean water first.
Safety: what to watch out for
The most important look-alike in the woods is the wood anemone. It flowers white in spring at the same time in the same place and is poisonous. You tell it apart by the leaves: wood anemone has deeply cut, finger-like leaves arranged in a whorl on the stem, and flowers with six to eight petals. Wood sorrel has three heart-shaped leaflets and flowers with exactly five petals with purple veins.
With clover, leave all yellow-flowered clover-like plants standing, such as bird's-foot trefoil or black medick. Bird's-foot trefoil also contains cyanogenic glycosides. In general: only eat what you identify 100 %. If poisoning is suspected call 112, in Austria also 144, or a poison line.
Anyone prone to kidney stones or with kidney disease, gout or rheumatism does without wood sorrel. Children eat only a few leaflets. Because both plants grow on the ground, they can be soiled with fox tapeworm eggs and other germs. Thorough washing or brief boiling helps; avoid dog areas, path edges and fertilised or sprayed fields completely.
When it makes sense – and when it does not
Wood sorrel and clover are nice seasonings for camp food: a few sour leaflets over fish or flatbread, clover flowers in a salad or as tea. They are easy to find, and children can learn with them, under supervision, to look at plants closely and compare features.
Neither is any use as food. Anyone hungry in an emergency will not be filled by wood sorrel – and a large portion would even do harm because of the oxalic acid. In a real emergency, the time and strength for gathering are better spent on shelter, water and being found.
Nothing is picked in protected areas. Outside them, the German Federal Nature Conservation Act allows collecting small amounts for your own use; in Austria regional laws apply. Only cut individual leaves and flowers and leave the plants in the ground.
Good to know
The name oxalic acid comes from the scientific name of wood sorrel: Oxalis. In the past, a salt was even extracted from wood sorrel to remove rust and ink stains – a sign of how potent the substance is.
A few crushed wood sorrel leaves in a bottle of treated water give a slightly sour taste. Take the leaves out afterwards. They do not replace water treatment, though – water from nature is always boiled, filtered or disinfected first.
The famous four-leaf clover is a rare quirk of nature in white clover. Other features count for recognition: leaf shape, flower colour, habitat. If you always check these features together, you will not confuse anything.
Step by step
Recognise wood sorrel
Wood sorrel grows in shady woods, often as a carpet, especially under spruce and beech. Each leaf has three heart-shaped leaflets with the point towards the centre, which fold down at night, in rain and in strong sun. In April and May it flowers with single white flowers with five petals and fine purple veins.
- 1
Recognise wood sorrel
Wood sorrel grows in shady woods, often as a carpet, especially under spruce and beech. Each leaf has three heart-shaped leaflets with the point towards the centre, which fold down at night, in rain and in strong sun. In April and May it flowers with single white flowers with five petals and fine purple veins.
- 2
Recognise clover
Clover grows in meadows and lawns in the sun. Its three leaflets are oval, not heart-shaped, and often carry a pale, V-shaped mark. The flowers stand together in round heads: white in white clover, pink to purple-red in red clover.
- 3
Rule out look-alikes
The poisonous wood anemone flowers in spring in the same woods, but has deeply cut, finger-like leaves and white flowers with six to eight petals. Leave yellow-flowered clover-like plants such as bird's-foot trefoil or black medick standing too. If even one feature does not fit, do not gather.
Only eat what you identify 100 %.
- 4
Choose a clean gathering spot
Gather away from paths, dog areas, roads and fertilised or sprayed fields. Nothing is picked in protected areas. Only cut individual leaves or flowers and leave the plant in the ground.
- 5
Gather small amounts
For one person a small handful of wood sorrel leaves is enough as seasoning. From clover you mainly gather the flower heads and a few young leaves. Check every piece in the container once more.
- 6
Wash thoroughly
Wash everything thoroughly in several rounds of clean water. Clover leaves are boiled or steamed briefly because they are hard to digest raw. If you have doubts about how clean the spot was, briefly cook the wood sorrel too.
- 7
Use sparingly
Sprinkle a few wood sorrel leaves over bread, fish or vegetables or add them to drinking water for a sour taste. Clover flowers go raw in small amounts with salad or into tea. Do not eat wood sorrel every day or as a main dish – neither will fill you up.
Common mistakes
- Eating wood sorrel as a salad in large amounts
- Confusing wood anemone with wood sorrel
- Gathering yellow-flowered clover-like plants
- Gathering in dog areas and along paths
- Eating unwashed
- Pulling up whole plants
Quick view
Materials
Field guide to wild plants (for your region)
A book does not replace practice with a knowledgeable person
Identification apps can be wrong – never rely on them alone
Rigid collecting container (box, basket or mug)
One species per container – never mix in anything unknown
Knife (fixed or locking blade)
For cutting instead of pulling up
Cut away from your body.
Rules on carrying knives differ by region – check local rules.
Suitable for
- Fresh seasoning for salad, bread or water
- Plant recognition practice with children – supervised
- Spring to autumn
Not suitable for
- People with kidney stones, kidney disease, gout or rheumatism (wood sorrel)
- Pregnancy and breastfeeding in larger amounts (clover)
- As a staple food – both provide hardly any energy
- Plants from dog areas, path edges and fertilised or sprayed fields
Prerequisites
- Able to tell wood sorrel, clover and wood anemone apart reliably
- Clean water for thorough washing
- A gathering spot away from paths, dog areas, roads and sprayed fields
Safety
- Wood sorrel contains oxalic acid. It binds calcium and in larger amounts can cause poisoning and kidney problems. So only a small handful of leaves as seasoning, not daily and not as a salad. Anyone prone to kidney stones or with kidney disease, gout or rheumatism eats no wood sorrel; children only a few leaflets.
- Plants close to the ground can be contaminated with fox tapeworm eggs and other germs. Wash thoroughly with clean water or boil briefly; do not gather in dog areas or along paths. If poisoning is suspected call 112 (in Austria also 144) or a poison line.
How it works
Wood sorrel tastes sour because its leaves contain oxalic acid and its salts. In small amounts that is a pleasant flavour; in large amounts oxalic acid binds calcium in the body and strains the kidneys. Clover is mild and belongs to the legume family; its leaves are hard to digest raw and some clovers contain substances that are only harmless in small amounts. Both plants are seasoning, not a meal.
Advantages
- Easy to recognise and widespread
- Fresh flavour
- Good plant-recognition practice
Disadvantages
- Oxalic acid limits the amount
- Hardly any calories
- Risk of confusion with wood anemone
- Contamination near the ground possible
Deep knowledge
Background
Wood sorrel used to be used as a seasoning because of its sour taste; the name oxalic acid comes from its scientific name Oxalis. Food chemistry textbooks describe oxalic acid as a substance that binds calcium and is harmful in larger amounts; toxicology handbooks list cases of poisoning from large amounts of oxalate-rich plants.
White clover can contain cyanogenic glycosides in its leaves, substances that can release hydrogen cyanide – another reason to eat clover only in small amounts and cooked. The Robert Koch Institute describes the fox tapeworm and advises washing or heating plants gathered close to the ground thoroughly.
Variants
- Sour water
- A few crushed wood sorrel leaves in a bottle of treated water give a slightly sour taste. Take the leaves out afterwards and do not eat them too; they do not replace water treatment.
- Clover flower tea
- Pour hot, boiled water over a handful of red clover flowers and let them steep for ten minutes. Only flowers from clean meadows; avoid during pregnancy.
Common mistakes
- Eating wood sorrel as a salad in large amounts
- Confusing wood anemone with wood sorrel
- Gathering yellow-flowered clover-like plants
- Gathering in dog areas and along paths
- Eating unwashed
- Pulling up whole plants
Limits and risks
- No amounts in grams – contents vary widely
- No medical effect claimed
- Applies to Central Europe
- No substitute for a field guide and practice with a knowledgeable person
Material alternatives
Derived from material properties: a substitute must have all relevant properties. Observe the notes on the substitute.
- Rigid collecting container (box, basket or mug)
- Metal pot (stainless steel, aluminium, titanium) (Hot – scalding risk.), Single-wall stainless steel bottle (Heat only single-wall bottles without paint/plastic; remove the lid before heating.), Double-wall insulated bottle (Never heat directly.), PET bottle (clear, max. 2 litres) (Do not heat or place in a fire.), Food-grade water container (Only use containers that never held chemicals or fuel.), Airtight food-grade storage container (Fill only when clean and completely dry; never use containers that previously held chemicals.), Collapsible water container or bag (Protect from sharp objects.), Measuring jug, Food-grade water bag (Use only for drinking water, never for chemicals or fuel.), Fermentation jar or crock (Use only food-grade containers of glass, food-safe glazed stoneware or food-grade plastic – no metal containers for acidic food.), Resealable food bags (Use only bags intended for food; do not use with boiling water unless the manufacturer explicitly allows it.), Airy collecting bag or basket (Collect each species separately so nothing unknown gets mixed in)
Results come exclusively from structured entries. No improvised instructions are generated.
Sources
Springer (H.-D. Belitz, W. Grosch, P. Schieberle) (2009): Food Chemistry, 4th edition
Oxalic acid in plants, binding of calcium, health risk in larger amounts
Wissenschaftliche Verlagsgesellschaft Stuttgart (Dietrich Frohne, Hans Jürgen Pfänder): Giftpflanzen – Ein Handbuch für Apotheker, Ärzte, Toxikologen und Biologen
Oxalate-rich plants (Oxalis) and wood anemone (Anemone nemorosa) as poisonous; cyanogenic glycosides
Bundesinstitut für Risikobewertung (BfR) (2017): Risiko Pflanze – Einschätzung und Hinweise
Recognising poisonous plants and avoiding poisoning
Robert Koch-Institut: RKI-Ratgeber Echinokokkose
Fox tapeworm: wash or heat wild plants gathered close to the ground thoroughly
Bundesrepublik Deutschland (gesetze-im-internet.de) (2009): Gesetz über Naturschutz und Landschaftspflege (Bundesnaturschutzgesetz – BNatSchG), insbesondere § 39 und § 30
Collecting small amounts for personal use, not in protected areas
Gesundheitsportal Österreich (gesundheit.gv.at), Bundesministerium für Soziales, Gesundheit, Pflege und Konsumentenschutz: Vergiftungsinformationszentrale (VIZ)
Poison information line in Austria (VIZ), available around the clock; in acute danger 112 or 144