Licorice Root

Licorice Root

　　Also known as sweet herb. Licorice is the root and rhizome of the leguminous plant Glycyrrhiza uralensis Fisch., and is one of the most commonly used medicinal substances in clinical practice. Raw licorice can clear heat, detoxify, moisten the lungs, relieve coughs, and harmonize the properties of other herbs; processed licorice can tonify the spleen and boost qi, and is used in particularly large clinical doses, as well as being exported in large quantities. Beyond medicine, licorice is also widely used in food as an additive in pastries. Its sweetness is one hundred times that of sucrose. Western countries import large amounts of licorice to extract glycyrrhizic acid, which is used in the treatment of AIDS. In the context of today’s western development initiatives, licorice plays an even more significant role—contributing to the conversion of farmland to forest, the construction of scenic landscapes, and stronger soil and water conservation. Farmers in northern Shaanxi and people across the western region report that simply scattering licorice seeds on the ground will result in germination, and the plant is extremely drought-resistant. Licorice grows in northwestern, northern, and northeastern China.

　　Licorice was first recorded in the “Shennong Bencao Jing” (The Divine Farmer’s Materia Medica Classic). It has a long history of medicinal use. As early as over two thousand years ago, the “Shennong Bencao Jing” listed it as a top-grade herb. The Southern Dynasties physician Tao Hongjing revered licorice as the “Guolao” (national elder), stating: “This herb is the king of all medicines; few prescriptions are made without it.” “Guolao” refers to the title of imperial tutor. The reason licorice is honored as the “imperial tutor” of herbs is explained by Li Shizhen in the “Compendium of Materia Medica”: “Among all herbs, licorice is the sovereign, treating seventy-two types of mineral and stone toxins, neutralizing one thousand two hundred types of plant toxins, and harmonizing all herbs with great merit—thus earning the title ‘Guolao.’”

　　Licorice is a perennial herbaceous plant, growing about 30–70 cm tall, rarely reaching 1 meter, with a cylindrical rhizome; the main root is very long, thick, and has a reddish-brown to dark brown outer skin. The stem is upright, slightly woody, covered with white short hairs and glandular scales or glandular hairs. It has odd-pinnate compound leaves, with lanceolate stipules that fall off early; there are 4–8 pairs of leaflets, with very short petiolules about 1 mm long; the leaflets are ovate, ovate-elliptic, or occasionally nearly round, 2–5.5 cm long and 1.5–3 cm wide, with acute or nearly blunt tips, and usually rounded bases, both surfaces covered with glandular scales and short hairs. The racemes are axillary, densely flowered, and 5–12 cm long; the calyx is bell-shaped, about half as long as the corolla but slightly longer, with five calyx teeth that are lanceolate and slightly longer than the calyx tube, covered with short hairs and glandular scales; the corolla is pale lilac, about 14–16 mm long, with a large banner petal that is oblong-elliptic, rounded or slightly notched at the tip, with a short claw at the base, while the keel petal is straight and shorter than the wing petals, also having long claws; there are 10 stamens in two groups, with filaments of varying lengths and anthers of unequal sizes; there is one pistil with a styleless ovary. The pod is linear-oblong, sickle-shaped or curved into a ring, usually 6–8 mm wide, densely covered with brown hooked glandular hairs. There are 2–8 seeds, which are flattened round or kidney-shaped, black and smooth. Flowering period is June to July, and fruiting period is July to September.

　　The upper part of the rhizome (licorice head), the tip or fine roots (licorice tip), and the parts of the root or rhizome filled with dark brown resinous material (licorice node) are also used medicinally, each detailed in separate entries.

　　Licorice is also widely used in the food industry, for refining candies, preserved fruits, and chewing gum. Licorice extract serves as an emulsifier in chocolate production, enhances the flavor and aroma of beer, improves the viscosity and color of dark beer, and is used in making certain soft drinks and liqueurs; it also corrects the taste of cigarettes. In chemical and dyeing industries, licorice has many applications.