4. AMYRIS L.
Glabrous glandular-punctate trees or shrubs, with balsamic resinous juices. Leaves opposite or rarely opposite and alternate, 3-foliolate, without stipules, persistent; leaflets opposite, petiolulate, entire or crenate. Flowers white, minute, on slender bibracteolate pedicels, usually in 3-flowered corymbs in terminal or axillary branched panicles; calyx 4-toothed, persistent; petals 4, hypogynous, much larger than the calyx-lobes, spreading at maturity; disk of the staminate flower inconspicuous, that of the pistillate and perfect flowers thickened and pulvinate; stamens 8, hypogynous, opposite and alternate with the petals; filaments filiform, exserted; anthers ovoid, attached on the back below the middle; ovary ellipsoid or ovoid, 1-celled, rudimentary in the staminate flower; style short, terminal, or wanting; stigma capitate; ovules collateral, suspended near the apex of the ovary, anatropous. Fruit a globose or ovoid aromatic drupe; stone 1-seeded by abortion, chartaceous. Seed pendulous, without albumen; seed-coat membranaceous; cotyledons plano-convex, fleshy, glandular-punctate.
Amyris is confined to tropical America and northern Mexico. Of the twelve or fourteen species which have been distinguished two extend into the territory of the United States; one of these is a small West Indian tree common on the shores of southern Florida, and the other, Amyris parvifolia A. Gray, a Mexican shrub, grows in Texas near Corpus Christi, Neuces County, and near the mouth of the Rio Grande. Amyris is fragrant and yields a balsamic aromatic and stimulant resin, and heavy hard close-grained wood valuable as fuel and sometimes used in cabinet-making.
The generic name, from μύῤῥα, relates to the balsamic properties of the plants of this genus.
1. [Amyris elemifera] L. Torch Wood.
Leaves 3-foliolate, with slender petioles 1′—1½′ long, and broad-ovate or rounded obtuse acute or acuminate leaflets cuneate at base, or sometimes ovate-lanceolate or rhombic-lanceolate, entire or remotely crenulate, coriaceous, lustrous, dark yellow-green, conspicuously reticulate-veined, covered below with minute glandular dots, 1′—2½′ long, with slender petiolules, that of the terminal leaflet often 1′ or more long and twice as long as those of the lateral leaflets. Flowers in terminal pedunculate or nearly sessile panicles appearing in Florida from August to December. Fruit ripening in the spring, ovoid, often nearly ½′ long, black covered with a glaucous bloom, with thin flesh filled with an aromatic oil and of rather agreeable flavor.
A slender tree, 40°—50° high, with a trunk sometimes, although rarely, a foot in diameter, and slender terete branchlets covered with wart-like excrescences, at first light brown, becoming gray during their second season. Bark of the trunk thin, gray-brown, slightly furrowed and broken into short appressed scales. Winter-buds acute, flattened, ⅛′ long, with broad-ovate scales slightly keeled on the back. Wood heavy, exceedingly hard, strong, close-grained, very resinous, extremely durable, light orange color, with thin rather lighter colored sapwood of 12—15 layers of annual growth; often used as fuel.
Distribution. Florida, Mosquito Inlet, Volusia County, to the southern keys; common in the immediate neighborhood of the coast to the rich hummocks of the interior, and of its largest size on Umbrella Key; on the Bahama Islands and on many of the Antilles.