Detailed Explanation of Licorice Variety Classification and Cultivation Methods

Licorice is the dried root and rhizome of the legume plants Glycyrrhiza uralensis Fischer., Glycyrrhiza inflata Bat., or Glycyrrhiza glabra L., used for medicinal purposes. It has effects such as clearing heat and detoxifying, relieving cough and phlegm, tonifying the spleen and harmonizing the stomach, and harmonizing various medicines. It treats sore throat, cough, palpitations, abdominal deficiency pain, ulcers and sores, and other conditions. Main growing and planting regions of licorice: originally wild in calcareous soils of arid grasslands in northwest China.

Plant Morphology of Licorice

Erect genus, leaves alternate, odd-pinnate compound leaves, leaflets 7-17, elliptical-ovate, racemes axillary, pale purplish-red, papilionaceous flowers. Oblong pods, sometimes sickle-shaped or annularly curved, densely covered with brown stinging-hair-like glandular hairs. Flat-round seeds. Flowering period June-July, fruiting period July-September.

Ecological Conditions of Licorice

Licorice mostly grows in arid and semi-arid desert steppes, desert margins and loess hilly areas, and is also easily propagated in fields and river beach lands of the Yellow River irrigation districts. It has strong adaptability and strong stress resistance. In our country, licorice grows in the northwest, north China and northeast regions. It prefers dry climates, tolerates cold, wild on arid calcareous land, cultivated in well-drained sandy loam with low groundwater levels. It avoids high groundwater levels and waterlogged acidic soils. Neutral or slightly alkaline soil is best.

Variety Classification and Cultivation Methods of Licorice

1. Licorice: Root is cylindrical, 30-120cm long, 0.6-3cm in diameter. Outer bark varies in tightness, reddish-brown, dark brown or grayish-brown, with obvious wrinkles and furrows, commonly called “drawn furrows and sunken ridges”, with sparse fine root scars. Lenticels transverse and long, both ends of the cut surface slightly sunken in the center. The cut center shrinks to the size of a pepper eye, called “pepper eye”. Texture solid and heavy, fracture fibrous, yellowish-white, starchy, with obvious cambium ring patterns and radial striations, with fissures. Rhizome surface has bud scars, cross-section center has pith. Slight odor, taste sweet and special.

2. Glycyrrhiza glabra: Root and rhizome texture relatively solid, some have branches, outer bark not rough, mostly grayish-brown.

3. Glycyrrhiza inflata: Root and rhizome lignified, thick and strong, some indeed have branches, outer bark rough, mostly grayish-brown or grayish-tan; texture hard, woody fibers abundant, low starchiness. Adventitious buds numerous and robust.

Powdered licorice has a pale yellow, flat surface, with knife-cut and longitudinal cracks.

(I) West Licorice: Mainly includes products from the western part of Inner Mongolia's Yikezhao League, Bayannur League, Alxa League, and northern Ningxia, northern Shaanxi, northern Shanxi and the Hexi Corridor area of Gansu, all classified as this quality. What is produced here is all genuine licorice, usually with both ends cut evenly, strips relatively uniform, red in color, fine and tight bark texture, “drawn furrows and sunken ridges” and “pepper eyes” both relatively obvious, plenty of powder, sweet taste. In the past, it was further divided by production area into:

1. Liangwai Licorice: Produced in Hangjin Banner in southern Hetao. It is the finest among licorice, with a solid body, jujube-red outer bark, goose-yellow inner color, and plenty of powder.

2. Wangyedi Licorice: Mainly produced in the Dengkou area of Alxa Banner, also a superior licorice, its branches uniform, outer bark darker than Liangwai Licorice, powder content also sufficient.

3. Xizhen Licorice: Produced in Etuoke Town and the Taole and Yanchi areas of Ningxia, its stems also relatively uniform, bark reddish-brown, powder content and texture inferior to the previous two, but still a high-quality licorice.

In addition, there are also Shanghechuan Licorice (Dalad Banner area), Xiahechuan Licorice (Baotou area and Togtoh Banner) and others produced in other areas, whose quality is inferior. The commodity is mostly loose-bodied, uneven strips, poor bark color (grayish-brown), powder quality inferior to authentic products, and inner color old yellow.

(II) East Licorice: Refers to products mainly produced in eastern Inner Mongolia, the northeast region, and the Hebei and Shanxi areas. Its commodity often has reed heads, so the heads and tails are not removed. Relatively long, sometimes branched, tails also relatively thin, epidermis relatively rough, often appearing semi-detached, body light and texture loose, fracture often fibrous, cut surface with many fissures, powder content inferior to West Licorice. Inner color yellow or old yellow. Often called “Hada Licorice”. Northeast products have sufficient sweet taste, often used as food, in the past exported to Japan in large quantities. Products from Hebei within the passes and central Shanxi have a relatively weaker sweet taste.

(III) Xinjiang Licorice: In the past, Xinjiang licorice was rarely used medicinally due to inconvenient transportation and mixed inferior strips. In recent years, because wild licorice resources (especially authentic production areas in Inner Mongolia) have been severely damaged, Xinjiang licorice, due to its large quantity, has gradually become one of the mainstream varieties. It includes large distributions from Xinjiang to the west of the Hexi Corridor in Gansu. The main characteristics of its products are mixed strips; licorice from all three plant sources has been seen (see the identification of the three licorices above), especially Glycyrrhiza inflata and Glycyrrhiza uralensis are more common; the latter, based on its traits, can be classified into the above West Licorice and East Licorice through processing (see national specifications and grades). Glycyrrhiza inflata, because of its gray color, rough bark, lignification, poor powder content, and thick and strong form, sweet taste but slightly bitter, is commonly called “black ghost licorice”. It is mostly used as honey-processed licorice to mask its color. It is also often used as an industrial raw material. Producing licorice extract, licorice tablets, etc.

There are mainly two cultivation methods for licorice. (1) Direct seeding, generally using drill sowing, row spacing 30-50cm, furrow depth 3-4cm, covering soil 2cm, sowing rate 2-3kg per mu. Because direct-seeded products have many branch roots, roots thick at top and thin at bottom, mostly failing to meet quality standards, and because digging is laborious and labor-intensive, generally only seed-production fields use this method in production. (2) Seedling transplanting, mostly used in production, because of its high yield, excellent quality, low labor intensity, and high economic benefit.