in botany: A genus of the monogynia order, belonging to the decandra clas of plants; and in the natural method ranking under the 14th order, Grumiales. The calyx is pentaphyllous; there are five petals; the nectarium is pentaphyllous; there are from two to five seed-cases standing afunder, and monospermous. There are three species, the amara, simaruba, and excelsa or polygama.

The quassia amara grows to the height of several feet, and sends off many strong branches. The wood is of a white colour and light; the bark is thin and grey; the leaves are placed alternately on the branches, and consist of two pair of opposite pinnae, with an odd one at the end; all the leaflets are of an elliptical shape, entire, veined, smooth, pointed, sessile, on the upper surface of a deep green colour, on the under paler: the common footstalk is articulated, and winged, or edged, on each side with a leafy membrane, which gradually expands towards the base of the pinnae: the flowers are all hermaphrodite, of a bright red colour, and terminate the branches in long spikes: the bractee or floral leaves are lance-shaped or linear, coloured, and placed alternately upon the peduncles: the calyx is small, persistent, and five-toothed: the corolla consists of five lance-shaped equal petals, at the base of which is placed the nectary, or five roundish, coloured, scales: the filaments are ten, slender, somewhat longer than the corolla, and crowned with simple anthers, placed transversely: the receptacle is fleshy and orbicular: the germen is ovate, divided into five parts, and supports a slender style, longer than the filaments, and terminated by a tapering stigma: the capsules are five, two-celled, and contain globular seeds. It is a native of South America, particularly of Surinam, and also of some of the West Indian islands. The root, bark, and wood, of this tree have all places in the materia medica. The wood is most generally used, and is said to be a tonic, stomachic, antifeptic, and febrifuge.

The quassia simaruba is common in all the woodlands in Jamaica. It grows to a great height and considerable thickness. The trunks of the old trees are black and a little furrowed. Those of the young trees are smooth and gray, with here and there a broad yellow spot. The inside bark of the trunk and branches is white, fibrous, and tough. It tastes slightly bitter. On cutting or stripping off this bark, no milky juice issues, as has been mentioned by various authors. The wood is hard, and useful for buildings. It splits freely, and makes excellent staves for sugar hogsheads. It has no sensible bitter taste. The branches are alternate and spreading. The leaves are numerous and alternate. On the upper side, they are smooth, shining, and of a deep deep green colour; on the under side they are white. The flowers appear about the beginning of April. They are of a yellow colour, and placed on spikes beautifully branched.

The fruit is of that kind called a drupa, and is ripe towards the end of May. It is of an oval shape, is black, smooth, and shining. The pulp is fleshy and soft; the taste a nauseous sweet. The nut is flattened, and on one side winged. The kernel is small, flat, and tastes sweet. The natural number of these drupes is five on each common receptacle; but, for the most part, there are only two or three; the rest abort by various accidents. The roots are thick, and run superficially under the surface of the ground to a considerable distance. The bark is rough, scaly, and warted. The inside when fresh is a full yellow, but when dry paler. It has but little smell. The taste is bitter, but not very disagreeable. This is the true cortex simaruba of the shops. This tree is known in Jamaica by the names of mountain damson, bitter damson, and blue-wood. The shops are supplied with this bark from Guiana; but now we may have it from our own islands at a moderate expense. On examining the fructification, Dr Wright found this tree to be a species of quassia. Under that name he sent it to Europe, and Linnæus adopted it into his system. There are male flowers on one tree and female flowers on another; and this is invariably the case in Jamaica.

Most authors who have written on the simaruba agree, that in fluxes it restores the lost tone of the intestines, allays their spasmodic motions, promotes the secretions by urine and perspiration, removes that lowness of spirits attending dysenteries, and disposes the patient to sleep; the gripes and tenesmus are taken off, and the stools are changed to their natural colour and consistence. In a moderate dose, it occasions no disturbance or uneasiness; but in a large dose it produces sickness at stomach and vomiting. Negroes are less affected by it than white people. Dr Cullen, however, says, "We can perceive nothing in this bark but that of a simple bitter; the virtues ascribed to it in dysentery have not been confirmed by my experience, or that of the practitioners in this country; and leaving what others are said to have experienced to be further examined and considered by practitioners, I can only at present say, that my account of the effect of bitters will perhaps explain the virtues ascribed to simaruba. In dysentery I have found an infusion of chamomile flowers a more useful remedy." The quassia excelsa or polygama was named by Sir Joseph Banks, Dr Solander, and Dr Wright, pricrania amara, (see Prickanilla Amara.) It is ranked, however, by Mr John Lindsay, in a paper in the third volume of the Edinburgh Transactions, under quassia, who gives the following description of it. "It is very common in the woodlands of Jamaica, is beautiful, tall, and stately, some of them being 100 feet long, and ten feet in circumference eight feet above the ground. The trunk is straight, smooth, and tapering, lending off its branches towards the top. The outside bark is pretty smooth, of a light gray or ash colour, from various lichens. The bark of the roots is of a yellow cast, somewhat like the cortex simaruba. The inner bark is tough, and composed of fine flaky fibres. The wood is of a yellow colour, tough, but not very hard. It takes a good polish, and is used as flooring. The leaves are sub-alternate; the small leaves are in pairs, from five to eight, standing opposite to each other on short footstalks, and ending with an odd one. They are of an oblong oval shape, and pointed; the ribs reddish, and the young leaves are covered with a fine brownish down. The flowers come out in bunches or clusters from the lower part of the last shoot before the leaves, and stand on round footstalks. The flowers are small, of a yellowish green colour, with a very small calyx. The male or barren tree has flowers nearly similar to the hermaphrodite, but in it there are only the rudiments of a style.

"The fruit is a smooth black drupa, round-shaped, and of the size of a pea. There is but little pulp, and the nut covers a roundish fleshy receptacle. It flowers in October and November, and its fruit is ripe in December and January. Except the pulp of the fruit, every other part of this tree has an intensely bitter taste. In taste and virtues it is nearly equal to the quassia of Surinam, and I am credibly informed is sold in London for the quassia amara; and it may be safely used in all cases where that drug has been thought proper, whether as an antifeptic, or in cases of weakness in the stomach and bowels. It may either be given alone, or joined with the Jesuit's bark. The happiest effects result from the use of this medicine in obliterating fevers from marsh miasmata, in agues which had resisted the use of Jesuit's bark, and in dysenteries of long standing. It is in daily practice in dropsies from debility, either in simple infusions or tincture by itself, or joined with aromatics and chalybeates. Dr Drummond, an eminent physician in Jamaica, prescribes it with great success in the above cases, as well as in amenorrhoea, chlorosis, dyspepsia, and in that species of pica called dirteating, so fatal to a number of negroes.

"The bark of the quassia polygama, but especially the wood, is intensely bitter. They may both be used in various forms. In certain cases of dropsy, aromatics and preparations are joined to it, also in amenorrhoea and chlorosis; and in worm fevers, the cabbage-bark, or other vegetable anthelmintics."