The calyx is combined with the ovary and bordered with 4 or 5 small teeth. The corolla, which is of a creamy white, is monopetalous with a very short tube and 5 spreading ovate lobes. The stamens which are about as long as the divisions of the corolla and alternate with them, are inserted in the tube of the latter. The yellow pollen which thickly powders the flowers, appears under the microscope 3-pored. The projecting ovary is crowned by a 2-or 3-lobed sessile stigma.
For use in pharmacy, the part of the flower most desirable is the corolla, to obtain a good proportion of which the gathered cymes are left for a few hours in a large heap; the mass slightly heats, the corollas detach themselves, and are separated from the green stalks by shaking, rubbing, and sifting; they require to be then rapidly dried. This done, they become much shrivelled and assume a dull yellow tint. When fresh, they have a sweet faint smell, which becomes stronger and somewhat different by drying, and is quite unlike the repulsive odour of the fresh leaves and bark. Dried elder flowers have a bitterish, slightly gummy flavour. On the Continent they are sold with the stalks, i.e. in entire cymes.
Chemical Composition—Elder flowers yield a very small percentage of a butter-like essential oil, lighter than water, and smelling strongly of the flowers; it is easily altered by exposure to the air.[1273] The oil is accompanied by traces of volatile acids.
Uses—Elder flowers are only employed in British medicine for making an aromatic distilled water, and for communicating a pleasant odour to lard (Unguentum Sambuci). The flowers of Sambucus canadensis L.[1274] indigenous in the United States, which are extremely similar to those of our species, appear to be more fragrant. The leaves of the latter are sometimes used for giving a fine green tint to oil or fat, as in the Oleum viride and Unguentum Sambuci foliorum of the shops. The bark, once much employed, is now obsolete.
RUBIACEÆ.
GAMBIER.
Catechu pallidum, Extractum Uncariæ; Gambier, Pale Catechu, Gambier Catechu, Terra Japonica; F. Gambir, Cachou jaune; G. Gambir.
Botanical Origin—1. Uncaria Gambier Roxb. (Nauclea Gambir Hunter) a stout climbing shrub, supporting itself by means of its flower-stalks which are developed into strong recurved hooks.[1275] It is a native of the countries bordering the Straits of Malacca, and especially of the numerous islands at their eastern end; but according to Crawfurd[1276] it does not seem indigenous to any of the islands of the volcanic band. It also grows in Ceylon, where however no use is made of it.
2. U. acida Roxb.,[1277] probably a mere variety of the preceding, and growing in the Malayan islands, appears to be used in exactly the same manner.
History—Gambier is one of the substances to which the name of Catechu or Terra Japonica is often applied; the other is Cutch, which has been already described ([p. 243]). By druggists and pharmaceutists the two articles are frequently confounded, but in the great world of commerce they are reckoned as quite distinct. In many price-currents and trade-lists, Catechu is not found under that name, but only appears under the terms Cutch and Gambier.