Guaiacum bijugum Stokes

Guaiacum officinale grows to a height of 9-12 m. Stem is generally crooked wood intensely hard, the branches knotty and bark deeply furrowed. The dense crown of close-growing foliage gives the tree a rounded, compact, net appearance. Each leaf is composed of 2 or 3 pairs of smooth, stalkless leaflets arranged on a slender mid-rib. The leaflets are 6-13 cm in length. There is much irregularity both in their size and shape: some are broadest above the middle (obovate), some almost blunt (obtuse). Beautiful blue flowers grow in great profusion and almost cover the tree and remain for a long time. As the older blooms fade from deep blue to paler shades, some becoming almost white, a striking variegation of colour is produced. The flowers grow in clusters at the ends of the branches. Each flower has 5 petals cupped in a small, finely hairy calyx, supported on a slender stalk. There are 10 stamens bearing golden yellow anthers. The fruit appears as small, round, compressed, yellow capsules, containing 5 cells; occasionally there are fewer. Each cell encloses a single seed. The generic name is derived from the Spanish one, ‘guayacan’ or ‘guayaco’, which itself originated from ‘hoaxacan’, the Mexican appellation of the plant. The specific name officinale means ‘officinal’, ‘used of medicinal or other plants procurable at shops’, or ‘used or recognized in pharmacy or medicine’.

In India the tree flowers at the end of the cold season and the commencement of the hot weather. In Bombay some of the trees bloom the whole year round.

G. officinale is an inhabitant of the West Indies, whence it has been introduced into India. It also grows in the arid plains stretching form the Florida Keys of USA to Venezuela. It is also credited to the natural flora of Honduras and Panama.

Guaiacum wood has been an article of trade since 1508, when it was introduced, via Spain, to the medical profession of Europe as a specific for many of the most serious diseases of mankind. The name lignum-vitae (wood of life) originated from the supposition that the material was possessed of extraordinary remedial powers. So great was the demand that for a time the wood was sold for as much as 7 gold crowns a pound. Numerous learned treatises were published and served to establish the reputation of the wood so firmly that it was nearly 200 years before it was seriously questioned. Both wood and resin are now medicinally obsolete except in certain proprietary decoctions.

G. officinale can be raised from seeds.

The resin sometimes flows spontaneously from the stem of the tree; at other times, it is obtained artificially by jagging or notching the stem and allowing the exuding juice to harden, or by boring holes in logs of the wood and then placing them on a fire so that the resin is melted and runs through the hole, or by boiling chips in salt and water, when the resin floats on the surface of the water.

Ornamental: G. officinale is distinctly ornamental on a lawn and is popular in Ghana and India.

Timber: The heartwood is greenish-brown; sapwood pale yellow, and usually thin, though if the logs have lain for a long time on the ground or in the water it may be entirely absent. Its great strength and tenacity, combined with the self-lubricating properties due to the resin content, make this wood especially adapted for bearing underwater. It is remarkable for the direction of its fibres, each layer of which crosses the previous diagonally. The most important as well as the most exacting use for it is for bearing or bushing blocks lining the stern tubes of propeller shafts of steamships. Other uses are mallets, pulley sheaves, caster wheels, bowling balls, masthead trucks, stencil and chisel blocks, cable dressers, and turned novelties; it is employed to a limited extent for brush backs. Steel and tube mills are made using lignum-vitae in increasing amounts to replace brass and babbit metal for bearings in roller mills and pumps, as the initial cost is less than metal, the life is several times longer, and lubrication is unnecessary. When rubbed and heated it gives off a faint, disagreeable aromatic odour, its taste is pungent and aromatic. Gum or resin: The most important product of G. officinale is resin obtained from the wood and bark, and used in powder, pill and tincture. It is an acrid stimulant and has been found efficient against various diseases, for example it is an ingredient of the well-known Plummer’s Pills, and is also one of the chief means employed to detect bloodstains. The resin known as ‘guaiac’ or guaiaci resin’ which is some demand by the drug trade, is extracted with alcohol or ether from sawdust and wood waste. It is obtained also in the form of exudations, called ‘tears’, from the living tree, or by heating sticks of the wood or by boiling chips and sawdust in water. The deep reddish brown colour of the resin changes upon oxidation to a blue or blue-green, a property made use of for differential staining. It has a brilliant resinous fracture. Of taste there is scarcely any, but it leaves a burning sensation in the mouth. Medicine: Apothecaries use shavings and raspings of the wood for medicinal purposes, in the same way the bark is employed for medicine. Resin is applied to the tooth for a toothache, and applied externally for rheumatism. For gout, blood pressure and arteriosclerosis resin is taken orally.