The Herb Hiding in Plain Sight — Korea's Solomon's Seal and the Tea Everyone Drinks

 The Herb Hiding in Plain Sight — Korea's Solomon's Seal and the Tea Everyone Drinks

If you've spent any time in a Korean office, a Korean home, or a Korean convenience store, you've almost certainly drunk 둥굴레차 without thinking much about it.

It comes in teabags, in cans, in those small paper cups from the hot water dispenser in the break room. The flavor is mild, slightly nutty, faintly sweet — the kind of tea you reach for without making a decision about it, the kind that tastes like background. It's been part of Korean daily life for long enough that most people who drink it regularly couldn't tell you what plant it comes from.

It comes from this one. The arching stems, the parallel-veined leaves, the small white-green bells hanging in clusters from the leaf axils — this is 둥굴레, and the roasted rhizome is what goes into the tea.

 The Plant: 둥굴레 (Polygonatum odoratum)

**Korean name:** 둥굴레  

**English common name:** Solomon's Seal, Angular Solomon's Seal  

**Scientific name:** *Polygonatum odoratum* (Mill.) Druce  

**Family:** Asparagaceae (아스파라거스과)  

**Blooms:** May – June  

**Height:** 30–60cm  

**Native range:** Europe, northern and eastern Asia including Korea  

**Toxicity:** ⚠️ Berries are toxic. Leaves and rhizomes edible with proper preparation.

*Polygonatum odoratum* is a perennial woodland herb that spreads by horizontal underground rhizomes, forming colonies over time in shaded or semi-shaded forest floors. The stem is angular — distinctly ridged rather than round — which gives the species its common English description of "angular Solomon's seal." It arches gracefully outward from the base, with leaves arranged alternately along it and flowers hanging in pairs or small clusters beneath the leaves, facing downward. The flowers are tubular, white with green tips, and faintly fragrant.

After flowering, small bluish-black berries develop — round, about the size of a large pea, and attractive-looking. They are toxic. This is the most important thing to know about 둥굴레 for anyone with children around.

 Why It's Called Solomon's Seal

The English name comes from the rhizome. When a stem dies back in autumn, it leaves a circular scar on the underground rhizome — and this scar, when the rhizome is cut, resembles a wax seal impression. The specific resemblance that gave it the name is to the Seal of Solomon, the six-pointed star that appears in Kabbalistic tradition and was believed to have magical protective properties.

Some herbalists argued the seal-like marks on the rhizome were themselves a divine indication of the plant's medicinal properties — specifically its ability to "seal" wounds and injuries, both physically and metaphorically. This kind of reasoning — reading plant morphology as a sign of intended medicinal use — was called the Doctrine of Signatures and was once a standard framework in European herbal medicine.

The Korean name 둥굴레 is more straightforwardly descriptive. 둥글다 means round, and 레 is a suffix. Round thing. The round rhizome sections, when dried and roasted, do indeed look like small rounds or discs — which is what you're looking at when you examine the contents of a 둥굴레차 teabag.

In Chinese herbal tradition, the plant is known as 玉竹 (*Yuzhu*) — jade bamboo — describing the smooth, jointed rhizome that resembles a bamboo stalk in miniature.

 The Rhizome and the Tea

둥굴레차 is made by slicing the rhizomes, drying them, and then roasting them until they develop a mild, toasty fragrance. The roasting step is important — it reduces the raw plant's bitterness and transforms it into the nutty, gentle flavor that makes the tea so easy to drink.

The tea became deeply embedded in Korean culture during the Joseon dynasty, when it was drunk both for pleasure and as a medicinal tonic. It was associated with longevity and gentle vitality — not a dramatic medicinal intervention, but the kind of quiet daily support that traditional East Asian medicine often emphasizes. In Korean herbal pharmacopeia, 둥굴레 was prescribed for lung dryness, thirst, general weakness after illness, and conditions associated with low vital energy.

It remained a kitchen staple through the 20th century, and when the Korean food industry began producing convenience beverages, 둥굴레차 was among the first to be packaged for mass consumption. The fact that it survived the transition into convenience store culture — that it's still being drunk in offices and break rooms alongside green tea and barley tea — says something about how established its place is.

I find something quietly interesting about that persistence. Of all the traditional Korean botanical drinks, 둥굴레차 is among the most genuinely mild and approachable. It doesn't assert itself. It tastes like something you could drink every day without noticing, which is precisely what millions of Koreans have done.

 What Traditional Medicine Said — And What Research Confirmed

In classical East Asian medicine, 둥굴레 (known in Chinese medicine as 玉竹, Yuzhu) is classified as a Yin-nourishing herb — one that supports the body's cooling, moistening functions, useful in conditions of dryness, heat, thirst, and depletion. It was prescribed for dry cough, general weakness, and to support the stomach and lung systems.

Modern pharmacological research has found genuine bioactive compounds in *Polygonatum odoratum* rhizomes: polysaccharides, steroidal saponins, flavonoids, and the glycoside azetidine-2-carboxylic acid. Studies have demonstrated antidiabetic activity — the polysaccharides appear to help regulate blood glucose levels, which connects to the traditional use for "thirst" conditions that now look like probable diabetes symptoms in historical texts. Immunomodulatory, antioxidant, and anti-fatigue activities have also been documented in published research.

The connection between traditional use and modern findings is particularly clear here. A plant used for thirst and depletion turns out to contain compounds that measurably affect blood sugar regulation. The traditional practitioners were observing something real.

 The Berry Warning

The berries of *Polygonatum odoratum* ripen in late summer — round, bluish-black, and appealing in appearance. They are toxic, causing gastrointestinal irritation and in larger quantities more serious effects. They should not be eaten.

This is worth emphasizing because the plant is otherwise well known as food and medicine, and the gap between the edible rhizome and the toxic berry is not always clearly stated in general references. The rhizome is edible. The young shoots in spring are edible as a 나물. The berries are not.

In the field, the berries appear after the flowers have dropped, hanging in the same position — underneath the leaves along the stem. If you encounter the plant in summer or autumn rather than spring, the berries will be visible and this is the identifying feature to watch for and avoid.

 Finding It in the Field

둥굴레 prefers the shaded understory of deciduous woodland — exactly the kind of forest floor habitat where the light is filtered and the soil stays cool and slightly moist. It often grows in colonies, the rhizomes spreading laterally underground and sending up new stems each spring. A hillside with one plant often has many.

The arching stem and the hanging flowers are the most distinctive visual features in spring. No other common Korean woodland plant produces quite the same silhouette — that graceful outward curve with small white bells suspended beneath the leaves. The leaves are a distinctive blue-green with prominent parallel veins, alternating along the stem.

The angular stem — distinctly ridged when you roll it between your fingers — is a reliable confirmation feature. Round stems are not 둥굴레.

For the tea, the rhizome is harvested in autumn when the aerial parts have died back. Wash, slice, dry, roast. Or buy it in a teabag from any Korean supermarket, which is considerably more convenient and perfectly acceptable.

 ⚠️ Disclaimer

This blog documents Korean plants and their traditional uses for educational and cultural purposes only. Nothing here is medical advice. **The berries of 둥굴레 are toxic and should not be eaten.** The rhizome and young shoots are traditionally edible, but correct identification is essential before consuming any wild plant. If you're considering using this plant medicinally, consult a qualified healthcare provider first.

*Photographed in Korea, April–May 2026. All field photography by The Korean Herbalist.*

**Tags:** 둥굴레, Polygonatum odoratum, Solomon's seal Korea, 둥굴레차, Korean herbal tea, Korean woodland plants, Korean traditional medicine, 玉竹 yuzhu, Korean spring plants, Asparagaceae Korea