The diagnostic features of liquorice (Glycyrrhiza glabra) include the following:

medicinal plants

  1. Root Characteristics:

    • Color: The dried roots are typically yellowish-brown to dark brown on the outer surface, and bright yellow internally.
    • Shape: The roots are cylindrical, fibrous, and can be branched. They can range in diameter from about 5 to 20 mm.
    • Texture: The surface is wrinkled with longitudinal ridges and is often covered in corky patches.
    • Fracture: The fracture is fibrous in the bark and splintery in the wood.

  2. Taste: Liquorice root has a characteristic sweet taste, which is due to the presence of glycyrrhizin, which is about 50 times sweeter than sucrose.

  3. Odor: It has a distinct and faint odor, often described as earthy or slightly aromatic.

  4. Internal Structure:

    • Cortex and Wood: The root has a clear separation between the cortex and the wood region.
    • Medullary Rays: In cross-section, broad medullary rays are visible radiating through the wood.
    • Vessels: Large vessels are scattered throughout the wood.

  5. Microscopic Features:

    • Cork Cells: The outer layer of the root contains numerous rows of cork cells.
    • Parenchyma: The cortex contains parenchyma cells with starch grains.
    • Calcium Oxalate Crystals: Crystals of calcium oxalate are often found in parenchyma cells.
    • Laticifers: Laticiferous vessels containing latex may be present.

  6. Chemical Composition:

    • Contains glycyrrhizin, a triterpenoid saponin responsible for its sweet taste.
    • Flavonoids like liquiritin and isoliquiritin, contribute to the color.
    • Contains starch, sugars, and other phenolic compounds.

These features help distinguish liquorice from other similar roots and allow it to be accurately identified in herbal medicine or pharmacognosy.