QUASSIA, a genus of trees and shrubs of the natural order simarubacea (q.v.); having hermaphrodite flowers, with five petals combined into a tube, and much longer than the small calyx, ten stamens, five germeus, and only cue style; the fruit composed of five drupes. Quassia amara is a native of the tropical parts of America, and of some of the West India islands. It is a shrub of 10 to 15 ft. high, with racemes of bright-red flowers, and large pinnate leaves, the stalks of which are remarkably winged and jointed. The wood, and particularly that of the root, has a very strong, bitter taste, and was at one time much used in medicine under the names of quassia-wood, bitterwood, etc. The flowers were valued in Surinam for their stomachic properties, as early as the beginning of the 18th c.; the wood of the root began to be known in Europe before the middle of that century, and was more fully brought into notice about 1756, by Rolander, a Swede, who had visited Surinam. and had learned its value from a negro called Quassi, or Qnasha. This negro had employed it with great success as a remedy for fevers, and although, as Rolander says, a very simple man, had acquired a great reputation by his use of it.
Linnaeus published a dissertation on it in 1763, and it was he who gave to the genus the name quassia, from the name of the slave by whom its medicinal qualities had been made known. The true quassia is now, however, little used; its name having been transferred to the bitterwood (q.v.) of the West Indies, picarna (or simaruba)excelsa, a lofty tree, the wood of which possesses the same properties, although in an inferior degree; but this inferiority is compensated by the greater facility with which any requisite supply is obtained. It is the wood of this tree which is now sold as quassia wood, or quassia-chips, in the shops. It is used to a considerable extent instead of hops for making beer, although the use of it is illegal iu Britain, and beer made with it is said to become muddy and flat, and not to keep. Quassia-wood is narcotic, and a decoction of it is used for killing flies. Cabinet-work made of it is safe from all attacks of insects.. In medicine, it is a valuable tonic; but in fevers, it is not to be compared with PeruVian bark and its alkaloids. Its properties depend chiefly on a bitter principle called quas -site or quassia.