History, Description, and Chemical Composition.—This plant is common to Europe and the United States, growing in cultivated grounds, moist thickets, and along banks of rivers, and flowering from June to September. Its root consists of a few hair-like fibers, of a reddish color. There are several species of Galium, all of which possess similar medicinal virtues, as Galium asprellum, Michaux, Rough or Pointed cleavers, which differs from the above in having its leaves in whorls of 4 or 6, and smaller, its fruit smooth, its stem less in length, and is perennial; Galium verum, Linné, or Yellow bedstraw, with an erect stem, leaves in whorls of 8, root long, perennial, fibrous, flowers densely paniculate, yellow, and terminal; Galium trifidum, Linné, or Small cleavers, with a perennial root, decumbent stem, herb smaller than the others, leaves in fours or fives, and white flowers; Galium triflorum, Michaux, or Sweet-scented bedstraw contains coumarin (C₉H₆O₂), an odorous principle found also in tonka beans, melilotus and other plants; the Galium tinctorium, a variety of the G. trifidum, having a stouter and a nearly smooth stem, leaves of the branches in fours, of the stem in sixes; peduncles 2 to 3-flowered; parts of the flowers usually in fours; G. lanceolatum, Torrey, and G. circæzans, Michaux, are sometimes known as Wild licorice on account of their taste.
In a green state these plants have an unpleasant odor, but are inodorous when dried, with an acidulous, astringent, and bitter taste. Cold or warm water extracts the virtues of the plants; boiling destroys them. The roots dye a permanent red, and the bones of the animals who eat the plant are said to be colored, similar to that caused by madder. The flowers are said to curdle milk, but this is not a constant effect. Analysis has detected in G. verum and G. aparine rubichloric acid, galitannic acid, citric acid, starch, chlorophyll, etc, G. aparine contains more citric acid than G. verum, while the latter holds the most galitannic acid. Oxalic acid may be present.