Distribution. Now widely spread by cultivation through the tropical and subtropical regions of the two worlds and probably a native of America from western Texas to northern Chile; growing in Texas apparently naturally in the arid and almost uninhabited region between the Nueces and Rio Grande; naturalized and now covering great areas in the valley of the Guadalupe River near Victoria, Victoria County, Texas.
Largely cultivated in southern Europe for its fragrant flowers used in the manufacture of perfumery, as an ornament of gardens in all warm countries, and in India as a hedge plant.
2. [Acacia tortuosa] Willd.
Leaves generally less than 1′ long, short-petiolate, with a slender puberulous rachis and usually 3 or 4 pairs of pinnæ; early deciduous; pinnæ sessile or short-stalked, remote, with 10—15 pairs of linear somewhat falcate leaflets, acute, tipped with a minute point, subsessile, light green, glabrous, 1/20′—1/16′ long. Flowers minute, bright yellow, very fragrant, in the axils of clavate pilose bracts, in heads ¼′—⅜′ in diameter, appearing in March with or just before the unfolding leaves, on clustered or solitary slender puberulous peduncles ½′—¾′ long, and furnished at apex with 2 minute connate bracts; calyx only about one third as long as the corolla, with short puberulous lobes; corolla puberulous at apex, less than half as long as the filaments; ovary covered with short close pubescence. Fruit elongated, linear, slightly compressed, somewhat constricted between the seeds, dark red-brown and cinereo-puberulous, 3′—5′ long and about ¼′ wide; seeds in 1 series, obovoid, compressed, dark red-brown, lustrous, about ¼′ long, faintly marked by large oval rings.
A tree, occasionally 15°—20° high, with a straight trunk 5′—6′ in diameter, stout wide-spreading branches forming an open irregular head, and slender somewhat zigzag slightly angled reddish brown branchlets roughened by numerous minute round lenticels, villose with short pale hairs, and armed with thin terete puberulous spines occasionally ¾′ long; in Texas usually shrubby, with numerous stems forming a symmetric round-topped bush only a few feet high. Bark dark brown or nearly black, and deeply furrowed.
Distribution. Valley of the Rio Cibolo to Eagle Pass on the Rio Grande, Maverick County, Texas; and in northern and southern Mexico, the West Indies, Venezuela, and on the Galapagos Islands; in Texas probably arborescent only on the plains of the Rio Grande near Spofford, Kinney County.
3. [Acacia Emoriana] Benth.
Leaves 3½′—4′ long, with a slender petiole and rachis, villose-pubescent early in the season, becoming nearly glabrous; and 4 or 5 pairs of pinnæ; falling late in the autumn; pinnæ on slender stalks ¼′ in length, with 5—7 pairs of oblong leaflets rounded and apiculate at apex, obliquely rounded at base, short-petiolulate, pointing forward, when they unfold densely villose above and on the margins, and hoary-tomentose below, becoming glabrous, gray-green rather darker above than below, ⅓′ long. Flowers subsessile, puberulous, in interrupted spikes, ¾′—1′ in length, densely hoary-tomentose when they first appear late in March, on villose peduncles ½′—1′ in length, and furnished near the apex with lanceolate caducous bracts; calyx about half the length of the ovate acute petals ciliate on the margins, about 1/12′ long and much shorter than the stamens; ovary stipitate, glabrous. Fruit fully grown in July, stipitate much compressed, rounded and sometimes slightly emarginate at apex, gradually narrowed and obliquely cuneate at base, with much thickened revolute undulate margins, densely pubescent early in the season, becoming puberulous, 5′ or 6′ long, 1¼′—1½′ wide and many-seeded, or nearly orbicular and 1 or 2-seeded; seeds in one series, oval, the two sides unsymmetric, obliquely pointed at base, rounded at apex, compressed, dark chestnut-brown and lustrous, ½′ long and ¼′ wide.