This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The common valerian, Valeriana officinalis, Linne (N.O. Valerianeoe), is an herbaceous plant widely diffused over Europe and Northern Asia. It is common in England in moist situations, attaining a height of 1 to 1.5 metres, and producing terminal corymbs of small white or pinkish flowers, each with a gamopetalous corolla and three stamens. It is cultivated in England (Derbyshire), and also in Holland and Germany, our supplies being derived partly from English and partly from foreign sources, but chiefly from cultivated plants. The drug, or at least a species of valerian, was well known to the Greeks and Romans; whilst the common valerian, or 'all-heal' as it is sometimes called, was a domestic medicine of the Anglo-Saxons. In the" Middle Ages the root was used not only as a medicine but also as a spice, and, curiously enough, even as a perfume.
The plant produces a short upright rhizome from which slender horizontal branches are emitted; the buds that terminate these branches develop into aerial shoots, which in their turn form erect rhizomes, and continue the life of the plant, the mother-rhizome perishing after flowering and fruiting. The drug is collected in the autumn, the lateral shoots are cut off for the propagation of the plant, and the rhizomes usually, especially if of large size, sliced longitudinally and dried.
In Derbyshire the wild plants are collected and planted out; the stems of the larger which would otherwise produce flowers are topped to prevent this from happening. In September or October all the tops above ground are cut off with a scythe, the rhizomes dug up, washed and dried, the larger being generally sliced.
The commercial drug consists of short erect conical rhizomes not more than 12 mm. thick and 25 mm. long, of a dull yellowish brown colour, usually halved, or quartered if large, but entire if small, and sometimes crowned with the remains of the stem and leaves. Internally the rhizome is firm and horny and of a whitish or yellowish colour; sometimes it becomes hollow, portions of the tissue remaining as transverse septa.
From the rhizome numerous brittle roots of the same colour and about 1.5 mm. thick are given off, as well as occasionally short, slender, lateral branches. In the commercial drug the roots seldom exceed 10 cm. in length and 2 mm. in diameter; they are plump or longitudinally striated, but usually not much shrivelled.
Sometimes the drug consists of small rhizomes about 5 mm. long, which are crowned with the remains of several leaves and bear rather short slender roots. These are formed from the lateral branches (runners) produced by the principal rhizome, which bear cataphyllary leaves; the buds in the axils of these develop leaves, roots are developed below, and independent plants are produced. Such plants may occasionally be found mingling their roots with those of the principal rhizome. Had they been allowed to continue their growth, they would ultimately have developed rhizomes as large as those of the parent plant.
The transverse section of the rhizome is irregular in outline and exhibits a comparatively narrow bark separated by a dark line (cambium) from an irregular circle of wood-bundles of varying size. The section of a root shows a thick bark and small wood.
Valerian rhizome has a powerful characteristic disagreeable odour and a camphoraceous, slightly bitter taste. The odour of the fresh rhizome, though disagreeable, is not strong, but it develops, during the drying, into the penetrating unpleasant odour of the drug. This change is due to the action of an enzyme, and may be prevented by boiling the root previous to drying it.
The student should observe
(a) The colour and odour of the drug,
(b) The short, erect rhizome surrounded by numerous roots,
(c) The characters of the section of the rhizome as given above.
The principal constituent of valerian root is the volatile oil which is contained in the sub-epidermal layer of cells in the root, not in isolated oil-cells or glands. Good valerian root yields about 1 per cent. of volatile oil, one of the constituents of which is bornyl isovalerianate. This constituent is gradually decomposed by an enzyme present, yielding free isovalerianic acid, an oily liquid possessing an unpleasant odour of valerian; to this body the unpleasant odour of valerian root is to be ascribed, and its gradual production from bornyl isovalerianate explains the development of the odour as the root dries.
Valerian root also contains two alkaloids, chatinine and valerianine, which require further investigation.
Chevalier (1907) found in the fresh rhizome an alkaloid, a glucoside, and a resin, all of which were physiologically active, and considered that the fresh root was preferable from a medicinal point of view to the dry, the reason being that the bornyl isovalerianate was present as such.
The drug is used as a powerful carminative, stimulant, and antispasmodic; it is given chiefly in hysteria, palpitation of the heart, etc.
Japanese Valerian, Kesso; the rhizome and roots of Valeriana officinalis, var. latifolia, Miquel; rhizome small, erect, crowned with scars or with the remains of aerial stems; brownish; odour resembling that of valerian but much stronger and somewhat aromatic; yields up to 8 per cent. of volatile oil containing l-bornyl isovalerianate and acetate, kessyl acetate, and terpenes.
Radix Valerianae, Majoris is the root of V. Phu, Linne, it has very little odour.
Mexican Valerian is the rhizome of V. officinalis growing in Mexico; it yields traces of volatile oil and a little free valerianic acid; the odour is feeble.
Nardus root is the rhizome and roots of Nardostachys Jatamansi, de Candolle (N.O. Valerianeoe), Alpine Himalayas; rhizome short, thick, dark grey, crowned by a bundle of fibres; odour resembles valerian; yield of oil about 1 per cent.