1. GUAIACUM L. Lignum-vitæ.
Trees or shrubs, with scaly bark, and stout terete alternate branchlets often with swollen nodes. Leaves petiolate, abruptly pinnate, with 2—14 entire reticulate-veined leaflets, and minute mostly deciduous stipules. Flowers terminal, solitary or umbellate-fascicled, pedicellate, from the axils of minute deciduous bracts; calyx-lobes slightly united at base, unequal, deciduous; petals broad-obovate, more or less unguiculate; stamens inserted on the inconspicuous elevated disk opposite to and alternate with the petals; filaments filiform, naked or bearing at base on the inner surface a minute membranaceous scale; anthers oblong; ovary raised on a short thick stalk, obovoid or clavate, 5-lobed, contracted into a slender subulate acute style; ovules 8—10 in each cell, suspended in pairs from the inner angle. Fruit fleshy, 5-celled, smooth, coriaceous, narrowed at base into a short stem, with 5 wing-like angles, ventrally and sometimes dorsally dehiscent. Seeds suspended, ovoid; seed-coat easily separable from the hard bony nucleus closely invested with a thin indistinct tegumen.
Guaiacum is confined to the New World, and is distributed from southern Florida through the Antilles, Mexico, and Central America to the Andes of Peru. Seven or eight species are distinguished.
Guaiacum produces heavy close-grained wood, the cells of the heartwood filled with dark-colored resin. The lignum-vitæ of commerce, largely used for the sheaths of ship-blocks, mallets, skittle-balls, ten-pin balls, etc., is produced principally by Guaiacum officinale L., of the Antilles and South America, and by Guaiacum sanctum L. Guaiacum resin is a stimulating diaphoretic sometimes used in the treatment of gout and rheumatism.
The generic name is from the Carib Guaiaco or Guayacon, the aboriginal name of the Lignum-vitæ.
1. [Guaiacum sanctum] L.
Leaves 3′ or 4′ long, with 3 or 4 pairs of obliquely oblong or obovate mucronate subsessile leaflets, membranaceous, light green and puberulous below when they first appear, becoming subcoriaceous, glabrous, dark green and lustrous on both surfaces, 1′ long and nearly ½′ wide, persistent until the appearance of the new growth in March or early April of the following year; stipules acuminate, tipped with a short mucro, pubescent, ⅛′ long, usually caducous, but sometimes persistent during the season. Flowers ⅔′ in diameter, opening almost immediately after the appearance of the new growth, and continuing to open during several weeks, solitary on a slender pubescent pedicel shorter than the leaves and usually produced 3 or 4 together at the end of the branches from the axils of the upper leaves, their bracts acuminate, minute, the 2 lateral rather smaller than the others; calyx-lobes obovate, slightly pubescent, especially on the outer surface near the base, and smaller than the blue petals twisted below from left to right, and thus appearing to be obliquely inserted; filaments naked; ovary obovoid, prominently 5-angled, glabrous, contracted at base into a short stout stalk. Fruit broad-obovoid, ¾′ long, ½′ wide, bright orange color, opening at maturity by the splitting of the thick rather fleshy valves; seeds black, with a thick fleshy scarlet aril-like outer coat.
A gnarled round-headed tree, sometimes 25°—30° high, with a short stout trunk occasionally 2½°—3° in diameter, slender pendulous branches, and branchlets conspicuously enlarged at the nodes, slightly angled, pubescent when they first appear, becoming in their second year glabrous, nearly white, and roughened by numerous small excrescences. Bark of the trunk rarely more than ⅛′ thick, separating on the surface into thin white scales. Wood dark green or yellow-brown, with thin clear yellow sapwood.
Distribution. Keys of southern Florida from Key West eastward; on the Bahama Islands and on several of the Antilles.