Lignum-Vitae

Part Ii: From the Commercial Standpoint

THE TRUE LIGNUM-VITAE OF COMMERCE

General Considerations 21 Present Sources of Supply 22 Future Sources of Supply 26 Value of Lignum-vitae Imports from 1900 to 1919 28 Uses of Lignum-vitae 28 Resin of Guaiacum: Its Properties and Uses 35

SUBSTITUTES FOR TRUE LIGNUM-VITAE

Woods of the Lignum-vitae Family 38 Woods of Other Families 39

SUMMARY AND CONCLUSIONS 44

REFERENCES 45 PLATES 49

LIGNUM-VITAE

A STUDY OF THE WOODS OF THE ZYGOPHYLLACEAE WITH REFERENCE TO THE TRUE LIGNUM-VITAE OF COMMERCE--ITS SOURCES, PROPERTIES, USES, AND SUBSTITUTES

BY SAMUEL J. RECORD Professor of Forest Products, Yale University

Part I: From the Botanical Standpoint

TREES AND WOODS OF THE LIGNUM-VITAE FAMILY

The true lignum-vitae belongs to the family Zygophyllaceae. The plants included in this family are mostly herbs, undershrubs, and shrubs; many of them are xerophytic. The only trees of the family belong to three closely related genera, namely Guaiacum, Porlieria, and Bulnesia. These are confined to tropical and sub-tropical regions of the Western Hemisphere.

The genus Balanites is included in the Zygophyllaceae by some botanists, but the structure of the wood has no resemblance to that of the three genera herein described.

Some botanists do not accord generic rank to Porlieria, but include it as a section of the extended genus Guaiacum (see 40, p. 59).

These three genera are composed of mostly evergreen trees and shrubs with opposite, compound, abruptly pinnate leaves, and with showy flowers solitary or in umbel-like clusters. The fruits are 2-5 lobed or parted, and each portion contains usually a single seed.

Guaiacum and Porlieria are alike in having blue or purple flowers, and leathery fruits containing seeds covered with a thin fleshy and often highly colored exocarp. Bulnesia, on the other hand, has yellow flowers, and the fruit, instead of being fleshy, is a 5-parted dry capsule with each part flattened into a conspicuous wing. The seeds are not provided with a fleshy covering.

In Guaiacum the stipules are deciduous, and the stamens are almost invariably without appendages. In the other two genera the stamens have prominent appendages and the stipules of the leaves are persistent, being thorny in Porlieria. The latter genus is further characterized by having small linear leaflets which exhibit nyctitrophic or “sleep” movements, and flowers that are tetramerous instead of pentamerous as they are in the other two.

These trees are found commonly in very dry regions and are accordingly of very slow growth, short-boled and bushy. The trunks, however, are often very stout with little taper. Some of the species of each genus are typically shrubs and others tend to become so in the most unfavorable sites. In the better situations, however, the trees grow more rapidly and are taller, straighter, and smoother, though such timber is not necessarily better and may, indeed, be of poorer quality on that account.

The woods of Guaiacum, Porlieria, and Bulnesia have many properties in common. They are cross-grained, extremely hard and horn-like, and are considerably heavier than water even when thoroughly dry; the heart portion is infiltrated with a fragrantly scented gum-resin which gives the wood an oily appearance and feel.

The maximum density determined by the writer was 1.32 (about 82-1/2 lbs. per cubic foot) for Nicaraguan lignum-vitae. Krais (“Die Hölzer”) gives the range for dry wood of Guaiacum as 1.17 to 1.39, or from 73 to nearly 87 pounds per cubic foot. Other reliable figures of density are 1.248 (Laslett) and 1.33 (Beauverie). Stone (46) gives 89 pounds per cubic foot for Guaiacum sanctum and cites Sargent (40) as authority. This is an error, as the values given by Sargent are 0.9563 to 1.2736, average 1.1432. Boulger (5) uses the same figure as Stone.

Growth rings are often distinct, largely on account of color variations, though affected more or less by the relative abundance of pores and by the distribution of wood parenchyma. The woods are diffuse-porous and the pores, which vary in size from minute and indistinct to readily visible in some cases, are open in the sapwood but commonly filled with resin in the heart. They are often associated with or surrounded by parenchyma which may extend into fine tangential or irregularly spaced concentric lines. The rays are uniform and numerous but are too fine to be seen without a lens.

On the longitudinal surface, typically the tangential, very fine and regularly-disposed cross-lines or “ripple marks” are visible with the lens but not without it. These lines are at right angles to the axis of the tree and are not affected in direction or regularity by the criss-crossing of the fiber-layers. The number of these markings per inch of length averages about 250, which is so much greater than in any other wood that this feature alone is sufficient to establish the identity of the group (36, p. 259). These ripple marks are also characteristic of the inner bark (secondary phloem). (For structure of the bark of Guaiacum officinale see Joseph Moeller’s “Anatomie der Baumrinden,” Berlin, 1882, pp. 332-3.)

In a specimen (Yale No. 974) of the shrub Larrea divaricata Cav. (Zygophyllaceae) from Argentina the number of ripple marks is about 270 per inch. In this wood the ground mass is composed of small thick-walled fiber-tracheids with very abundant and prominent bordered pits. The rays are 1 to 12, mostly 6, cells high, uni-seriate or more commonly bi-seriate in the median portion; rather indistinctly storied. The wood parenchyma contains crystals some of which are large and conspicuous.

Porlieria

The representatives of this genus are shrubs or small trees growing in dry sub-tropical regions, and are not of commercial importance. Four species have been described, one belonging to a group of plants connecting the Mexican and Texas flora, two inhabiting the corresponding zone in Argentina and Chile, and a fourth, little known, in Bolivia.

This fourth species is described by Baillon (Adansonia, 10:315-16, 1872) under the name of “Guaiacum (Porlieria) microphyllum.” It was found in Bolivia. The leaves are only 1/5 inch long and 1/6 inch broad.

Porlieria angustifolia Gray (= Guaiacum angustifolium Engl.) is found in western Texas and adjacent regions of Mexico where it is common on the dry gravelly mesas of the valley of the lower Rio Grande. It is a small tree with very knotty branches, attains a height of 25 to 30 feet and a diameter of 6 to 8 inches, becoming reduced to a low shrub toward its eastern, northern, and western limits. “The hard and heavy yellowish-brown wood is called ‘guayacan’ about Saltillo, and used as a sudorific and in venereal diseases.” (12, p. 113.)

“The wood is exceedingly heavy, very hard, close-grained, compact, the open ducts smaller and less regularly distributed than in Guaiacum; medullary rays very thin, numerous; color, rich dark brown turning green with exposure, the sapwood bright yellow; sp. gr. 1.1101; ash 0.51; probably possessing medicinal properties similar to those of lignum-vitae.” (39, p. 29.)

Porlieria Lorentzii Engl. is a shrub or small tree on the Argentine steppes where it occasionally reaches a height of 25 feet and a diameter of 10 inches. It is covered with a thin dark gray scaly bark. The yellowish wood is very compact and fine-textured and makes a fairly satisfactory substitute for boxwood in turnery and carving. Its most common use is in the manufacture of domestic utensils, particularly spoons, and to the latter owes its vernacular name of “cucharero” (maker of spoons). The Indians use the wood, called by them “chukupi,” for making smoking-pipes (44, p. 378; 49, p. 105.)

The above is probably the species referred to by Castro (8, p. 77) as “guayacan blanco,” “chuchupi,” “chucupi,” or “chucarea,” though he gives the scientific name as P. hygrometrica. The following information is on his authority: The tree is found in Córdoba, Salta, Jujuy, Tucuman, Mendoza, San Luis, San Juan, and La Rioja, and is very abundant in the Andean provinces. In its better development it reaches a height of 13 to 20 feet and a diameter of 4 to 6 inches. The wood is hard and very strong and resilient. Specific gravity 1.11. It is susceptible of a high polish, has a high luster, and on account of its flexibility is in demand for canes and whipstocks. It is also used for turnery and carves with ease. In general carpentry it finds a place in the making of sash, doors, and blinds.

Porlieria hygrometrica R. & P. (= Guaiacum hygrometricum Bail.), is an ungainly shrub with sprawling branches and dropping leaves. When it “sleeps” it gives the appearance of being diseased or even in a dying condition. It was discovered by Ruiz and Pavon, first in Peru near Huanuco, where it was called “turucasa,” meaning “thorns fragile and not sharp” (referring to the stipular spines); afterwards in Chile where the Spaniards, who have imputed to it the sudorific property of guaiac, call it “guayaco,” also “palo santo.” Misled, no doubt, by the common name, Molina, who did not see the plant, has erroneously referred to it as Guaiacum officinale L. (13, pp. 465-6.)

Bulnesia

This genus, so far as known, is confined to South America. There are eight species, but only two, the “palo santo” of Argentina and the “vera” of Colombia and Venezuela, supply timber of commercial value. The others are low-branching shrubs on the dry foothills of the Andes Mountains in Argentina.

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