Redwood sorrel (Oxalis oregana), a low-growing perennial found carpeting the floor of moist, shady forests along the Pacific coast, is a distinctive wild edible known for its heart-shaped leaves and lemony flavor. While it has been traditionally used by Native American tribes in small amounts, modern foragers must be cautious due to its oxalic acid content. This article explores how much redwood sorrel you can eat safely, its health implications, and best practices for responsible foraging.
The Role of Oxalic Acid in Redwood Sorrel
What is Oxalic Acid?
Oxalic acid is a naturally occurring organic compound found in many common plants, including spinach, rhubarb, and broccoli. It is responsible for the sour or tart taste of redwood sorrel. In small doses, it is generally harmless for most people. The primary concern arises from its ability to bind with calcium, which can prevent the body from absorbing this essential mineral. Over-consumption can lead to a state of calcium deficiency, and in extreme cases, the formation of calcium oxalate crystals in the kidneys, which can cause kidney stones and other serious health problems.
Safe Consumption Guidelines
Experts and foraging guides consistently stress that redwood sorrel should be consumed only in small quantities. There is no definitive "magic number" for how much is safe, as it depends on an individual's health, diet, and frequency of consumption. However, the general consensus is to treat it as a flavorful garnish rather than a primary leafy green. A handful of leaves mixed into a salad or soup is a reasonable serving size for an adult with no pre-existing conditions. Children should eat even less, often no more than a few leaves.
Individuals Who Should Avoid Redwood Sorrel
Certain individuals are at a higher risk of adverse effects from oxalic acid and should avoid or severely limit their intake of redwood sorrel. This includes:
- Pregnant and Breast-feeding Individuals: WebMD lists wood sorrel as unsafe for mothers and infants, and it should be avoided.
- Those with Kidney Issues: Individuals with a history of kidney stones or other kidney diseases are at a heightened risk because of the formation of calcium oxalate crystals.
- Sufferers of Arthritis, Gout, or Rheumatism: Oxalic acid can aggravate these conditions.
- Individuals with Stomach or Intestinal Disorders: The plant can cause irritation to the digestive tract.
Preparing Redwood Sorrel for Consumption
Cooking can help reduce the amount of oxalic acid in redwood sorrel, similar to spinach. This makes it a safer option for those who want to use it more regularly, though moderation is still key. The leaves can be used in a variety of culinary applications to add a citrusy zing.
- Raw Garnishes: A few fresh leaves add a sharp, zesty note to salads, soups, or dishes featuring dried fish, a practice used historically by Northwest tribes.
- Cooked Ingredients: Chop and add to soups or sauces toward the end of cooking. It wilts quickly, so minimal heat is needed.
- Flavoring Agent: Use the leaves and stems to flavor beverages or rhubarb-like pies.
- Infusions: A decoction can be made from the whole plant, as was historically used for medicinal purposes, though this should be approached with caution.
Redwood Sorrel vs. Common Sorrel
It is important not to confuse redwood sorrel (Oxalis oregana) with common or garden sorrel (Rumex acetosa), as they belong to different plant families, though both contain oxalic acid. Redwood sorrel is part of the Oxalis family, while common sorrel is in the buckwheat family (Polygonaceae). While their flavors share a similar tartness, their oxalic acid levels and other chemical compounds can differ.
| Feature | Redwood Sorrel (Oxalis oregana) | Common Sorrel (Rumex acetosa) |
|---|---|---|
| Appearance | Heart-shaped leaflets, often found in dense mats. | Arrow-shaped leaves, grows more upright. |
| Habitat | Moist, shaded forest floors, particularly in redwood and Douglas fir forests. | Open fields, grasslands, and cultivated gardens. |
| Flavor Profile | Lemony, tangy. | Tangy, slightly more acidic. |
| Oxalic Acid | Present in all parts, should be eaten in small quantities. | Present, requires moderation in consumption. |
| Culinary Use | Garnish, salads, soups, infusions. | Soups, sauces, salads, often used more like an herb. |
Conclusion: Practice Caution and Moderation
While redwood sorrel is a delicious and intriguing wild edible, its consumption must be approached with informed caution due to the presence of oxalic acid. The best practice is to eat it in small, controlled quantities, using it as a flavor enhancer rather than a bulk food item. Pay close attention to your body's reaction and err on the side of caution, especially if you or someone you are sharing with has a pre-existing medical condition. Responsible foraging and a deep understanding of potential health risks are crucial for safely enjoying the tangy treat of redwood sorrel.
