306 TREES OF NORTH AMERICA 



times nearly % thick but usually thinner, light gray slightly tinged with red, deeply 

 furrowed and broken on the surface into slightly appressed scales. Wood heavy, 

 hard, close-grained, dark orange color or sometimes dark brown, with thick light- 

 colored sapwood. 



Distribution. Dry limestone hills, or westward only in elevated mountain canons 

 in the neighborhood of streams; from the valley of the Colorado River, Texas, south- 

 ward into Mexico, and through the mountain regions of western Texas and southern 

 New Mexico to the Santa Rita Mountains of Arizona; common on the mountain 

 ranges of northern Mexico from Nuevo Leon to Chihuahua, and southward through 

 southern Mexico and Central America to Peru. 



Frequently planted in the countries south of the United States as a fruit-tree. 



2. TOXYLON, Raf. 



A tree, with thick milky slightly acrid juice, thick deeply furrowed dark orange- 

 colored bark, stout tough terete pale branchlets, with thick orange-colored pith, 

 lengthening by an upper axillary bud, marked by pale orange-colored lenticels and 

 armed with stout straight axillary spines, short stout spur-like lateral branchlets from 

 buds at the base of the spines, and thick fleshy roots covered by bright orange-colored 

 bark exfoliating freely in long thin persistent papery scales. Leaves involute in the 

 bud, ovate to oblong-lanceolate, acuminate and apiculate at the apex, rounded, wedge- 

 shaped or subcordate at the base, entire, penniveined, the veins arcuate near the mar- 

 gins and connected by conspicuous reticulate veinlets; their petioles elongated, slen- 

 der, terete, pubescent; stipules lateral, nearly triangular, minute, hoary-tomentose, 

 caducous. Flowers dioecious, light green, minute, appearing in early summer; calyx 

 4-lobed, the lobes imbricated in aestivation; corolla 0; thestaminate long-pedicellate, 

 in short or ultimately elongated racemes borne on long slender drooping peduncles 

 from the axils of crowded leaves on the spur-like branchlets of the previous year; 

 calyx ovate, gradually narrowed into the slender pubescent pedicel, coated on the 

 outer surface with pale hairs, divided to the middle into equal acute boat-shaped lobes; 

 stamens 4, inserted opposite the lobes of the calyx on the margins of the minute thin 

 pulvinate disk; filaments flattened, light green, glabrous, infolded above the middle 

 in the bud, with the anthers inverted and back to back, straightening abruptly in 

 anthesis and becoming exserted; anthers oblong, attached on the back near the mid- 

 dle, introrse, 2-celled, the cells attached laterally to a minute oblong or semiorbicular 

 connective, free and spreading above and below, opening by longitudinal lateral slits; 

 the pistillate sessile in dense globose inanv-flowered heads on short stout peduncles 

 axillary on shoots of the year; calyx ovate, divided to the base into oblong thick con- 

 cave lobes, rounded, thickened, and covered with pale hairs at the apex, longer than 

 the ovary and closely investing it, the 2 outer lobes much broader than the others, 

 persistent and inclosing the fruit; ovary ovate, compressed, sessile, green, and gla- 

 brous; style covered by elongated slender filiform white stigmatic hairs; ovule sus- 

 pended from the apex of the cell, anatropous. Drupes oblong, compressed, rounded 

 and often notched at the apex, acute at the base, with thin succulent flesh, and a 

 thin crustaceous light brown nutlet, joined by the union of the thickened and much 

 elongated perianths of the flowers into a globose compound fruit saturated with 

 milky juice, mammillate on the surface by their thickened rounded summits, light 

 yellow-green, usually of full size but seedless on isolated pistillate individuals. Seed 

 oblong, compressed, rounded at the base, oblique and marked at the apex by the 



