Chinese Licorice

Glycyrrhiza uralensis is native to the arid and semi-arid regions of East Asia, with a natural range spanning northern and northwestern China, Mongolia, and parts of Central Asia.

• The species name "uralensis" refers to the Ural region, reflecting early botanical collection records
• In China, primary wild populations are found in Xinjiang, Gansu, Inner Mongolia, Ningxia, and Shaanxi provinces
• The genus Glycyrrhiza comprises approximately 20 to 30 species distributed across Mediterranean Europe, Central Asia, Australia, and the Americas
• Center of diversity for the genus lies in the arid zones of Central Asia and the Middle East

Historical records of licorice use in China date back to at least the Han Dynasty (206 BCE–220 CE), with detailed descriptions in the Shennong Bencao Jing (Divine Farmer's Classic of Materia Medica), one of the earliest Chinese pharmacopoeias.

• Licorice root was traded along the ancient Silk Road, reaching the Middle East and Europe
• Ancient Egyptian, Greek, and Roman civilizations also used related Glycyrrhiza species medicinally

Chinese Licorice is a hardy perennial herbaceous plant typically growing 30 to 120 cm tall, with a robust, deep-penetrating root system.

Root & Rhizome:
• Primary root (taproot) is cylindrical, straight or slightly curved, 1 to 2+ cm in diameter, and can extend over 1 meter deep into the soil
• Outer bark is reddish-brown to dark brown; inner flesh is bright yellow when cut, with a distinctive sweet taste
• Rhizome (underground stem) is creeping and extensively branched, producing new shoots and enabling vegetative propagation
• Root and rhizome together constitute the primary medicinal parts ("gān cǎo" in Chinese)

Stems:
• Erect or slightly ascending, 50 to 150 cm tall
• Covered with glandular hairs and whitish tomentum (fine hairs)
• Branched, with a somewhat woody base

Leaves:
• Alternate, odd-pinnately compound, 10 to 20 cm long
• Composed of 7 to 17 leaflets, each ovate to elliptic (1.5–4 cm long)
• Leaflets are entire-margined, with glandular dots on the undersurface that secrete a resinous substance
• Stipules are small and caducous (falling off early)

Flowers:
• Papilionaceous (butterfly-shaped), characteristic of the Fabaceae family
• Pale purple to whitish-purple, arranged in axillary racemes 5 to 15 cm long
• Blooming period: June to August
• Calyx is tubular, 5-lobed, and glandular-hairy

Fruit & Seeds:
• Legume (pod), oblong, 1.5 to 3 cm long, slightly curved
• Covered with dense brownish glandular bristles (hooked hairs)
• Contains 2 to 8 small, reniform (kidney-shaped) seeds
• Seeds are smooth, dark brown to blackish, approximately 2 to 3 mm in diameter

Glycyrrhiza uralensis thrives in continental arid and semi-arid climates, demonstrating remarkable tolerance to drought, cold, and poor soils.

Habitat:
• Riverbanks, floodplains, and alluvial terraces in arid zones
• Steppe and desert margins with deep, well-drained sandy or loessial soils
• Roadsides, field margins, and disturbed grasslands at elevations of 400 to 1,500 meters
• Often found in association with other drought-tolerant species such as Artemisia and Stipa grasses

Climate:
• Prefers full sun; highly intolerant of shade
• Annual precipitation requirement: 150 to 400 mm (drought-tolerant)
• Tolerates extreme temperature ranges: from winter lows below −30°C to summer highs above 40°C
• Requires a distinct cold period for optimal root development

Soil:
• Deep, loose, well-drained sandy loam or loessial soils preferred
• Tolerates slightly alkaline conditions (pH 7.0–8.5)
• Root nodules with Rhizobium bacteria enable nitrogen fixation, allowing growth in nutrient-poor soils

Reproduction:
• Sexual reproduction via seeds; cross-pollinated primarily by bees and other insects
• Seeds have hard seed coats and may require scarification (mechanical or acid treatment) for reliable germination
• Vegetative reproduction via creeping rhizomes is common and often the dominant mode of spread in established populations
• Seed viability can remain high for several years under dry storage conditions

Wild populations of Glycyrrhiza uralensis have declined significantly over the past several decades due to over-harvesting of wild roots for the medicinal trade, habitat loss from agricultural expansion, and desertification.

• Listed as a protected species under China's Wild Plant Conservation Regulations (Category III nationally)
• Wild harvesting is restricted or banned in several provinces, including Inner Mongolia and Xinjiang
• Large-scale cultivation programs have been established in Gansu, Xinjiang, and Inner Mongolia to reduce pressure on wild stocks
• The species is included in the Chinese Pharmacopoeia (中华人民共和国药典) with strict quality standards for cultivated material
• IUCN Red List status: not formally assessed at the species level, but regional assessments indicate declining wild populations
• Sustainable harvesting practices (e.g., partial root collection, replanting of rhizome fragments) are being promoted

Chinese Licorice is cultivated commercially across northern and northwestern China, with increasing interest in sustainable agricultural production to meet pharmaceutical demand.

Light:
• Full sun essential; requires a minimum of 6 to 8 hours of direct sunlight daily
• Shade significantly reduces root biomass and glycyrrhizin content

Soil:
• Deep, loose, well-drained sandy loam or sandy soil is ideal
• Soil depth of at least 50 cm recommended to accommodate the long taproot
• Tolerates slightly alkaline conditions (pH 7.0–8.5)
• Avoid heavy clay soils that restrict root penetration

Watering:
• Drought-tolerant once established; overwatering is more harmful than underwatering
• Moderate irrigation during the first growing season to establish deep roots
• Reduce watering in the second year onward to encourage root thickening and glycyrrhizin accumulation
• Waterlogging causes root rot and should be strictly avoided

Temperature:
• Optimal growth temperature: 20 to 25°C during the growing season
• Extremely cold-hardy; tolerates winter temperatures below −30°C
• Requires a period of winter dormancy for normal growth cycle

Propagation:
• Seed propagation: seeds require scarification (mechanical abrigation or brief acid soak) to break hard seed coat dormancy; sow in spring
• Rhizome division: sections of rhizome with at least one bud can be planted directly in spring; faster establishment than seed
• Seedling transplanting: nursery-raised seedlings transplanted at 4 to 6 leaf stage

Harvesting:
• Roots are typically harvested in the autumn of the third or fourth year of growth
• Glycyrrhizin content peaks in autumn, making this the optimal harvest season
• Roots are washed, sliced, and dried for medicinal use

Common Problems:
• Root rot (Fusarium, Phytophthora) in poorly drained soils
• Aphid and leafhopper infestations on young shoots
• Powdery mildew in humid conditions
• Slow growth in compacted or nutrient-rich soils (excessive nitrogen reduces root quality)

Chinese Licorice root is one of the most versatile and widely used medicinal and commercial plant products in the world.

Traditional Chinese Medicine (TCM):
• Known as "gān cǎo" (甘草), classified as sweet in flavor and neutral in nature
• Primary TCM functions: tonifies the spleen and stomach qi, clears heat and resolves toxicity, moistens the lungs and stops cough, moderates urgency and alleviates pain
• Called the "guide herb" (引经药) for its ability to harmonize and direct the actions of other herbs in a formula
• Appears in a vast number of classical TCM prescriptions, including Gancao Tang, Xiao Chaihu Tang, and Sini San

Phytochemistry & Pharmacology:
• Contains glycyrrhizin (glycyrrhizic acid), 30–50× sweeter than sucrose, the primary bioactive compound
• Flavonoids: liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin — with documented antioxidant and anti-inflammatory properties
• Coumarins, triterpenoids, and polysaccharides also present
• Modern pharmacological studies have investigated effects including anti-inflammatory, antiviral, hepatoprotective, anti-ulcer, and immunomodulatory activities

Food & Consumer Products:
• Used as a natural sweetener and flavoring agent in candies, chewing gum, beverages, and tobacco products
• Licorice extract is used in some beers (particularly in Belgium and the Netherlands) for flavor and foam stability
• Widely used in confectionery, especially in Northern Europe (e.g., Scandinavian salty licorice)

Cosmetics & Personal Care:
• Licorice root extract is used in skincare products for its anti-inflammatory and skin-brightening properties
• Glycyrrhizin and glabridin are studied for inhibition of melanin production

Industrial:
• Foaming properties of saponins have been explored for fire extinguishing foams and industrial surfactants
• Historically used in fire extinguishers in the early 20th century