570 TREES OF NORTH AMERICA 



stipels, pale gray-green, glabrous and slightly puberulous on the upper surface, con- 

 spicuously glandular, with chestnut-brown glands, and pubescent especially on the 

 prominent midribs on the lower surface, reticulate-veined, '-' long, \'-\' wide, 

 with thickened slightly revolute margins. Flowers opening in May, nearly ty 

 long, on slender pubescent pedicels, in axillary pubescent spikes 3'-4' long; calyx 

 many-ribbed, pubescent, conspicuously glandular, half as long as the white petals 

 ciliate on the margins, and of nearly equal size and shape. Fruit ' long, pendent, 

 nearly straight or slightly falcate, thickened on the edges, with usually a single seed 

 near the apex; seed compressed, light reddish brown, ^' long. 



A tree, occasionally 18-20 high, with a trunk 6'-8' in diameter, separating 3- 

 4 above the ground into a number of slender branches, and branchlets coated at 

 first with ashy gray pubescence disappearing during the second year, and then 

 reddish brown and roughened by numerous glandular excrescences ; or more often a 

 low rigid shrub. Bark of the trunk about T y thick, light gray, and broken into 

 large plate-like scales, exfoliating on the surface into thin layers. Wood heavy, 

 hard, close-grained, light reddish brown, with thin clear yellow sapwood of 7 or 8 

 layers of annual growth. 



Distribution. Dry gravelly soil, on arid slopes and dry ridges; valley of the 

 upper Guadalupe River, western Texas, to the Santa Catalina and Santa Rita 

 Mountains, southern Arizona, and southward into northern Mexico; arborescent only 

 near the summit of the Santa Catalina Mountains. 



14. DALEA, L. 



Glandular-punctate herbs, small shrubs, or rarely trees. Leaves alternate, un- 

 equally pinnate, or simple in the arborescent species; stipules generally minute, sub- 

 ulate, deciduous. Flowers in racemes, their bracts membranaceous or setaceous, 

 broad, concave above, glandular-dentate; calyx 5-toothed or lobed, persistent, the 

 divisions nearly equal; corolla papilionaceous; petals unguiculate; standard cordate, 

 free, inserted in the bottom of the tubular disk connate to the calyx-tube, rather 

 shorter than the wings and keels, the claws adnate to and jointed upon the staminal 

 tube; stamens 10, or sometimes 9 through the suppression of the superior one, united 

 into a tube cleft above and cup-shaped toward the base; anthers uniform, often 

 surmounted by a gland; ovary sessile or short-stalked, contracted into a slender 

 subulate style, with a minute terminal stigma; ovules 4-6 attached to the inner angle 

 of the ovary, superposed. Legume ovate, sometimes conspicuously ribbed, more or 

 less inclosed in the calyx, membranaceous, indehiscent, 1-seeded; seed reniform, 

 without albumen; testa coriaceous; embryo filling the cavity of the seed; cotyledons 

 broad and flat; radicle superior, accumbently reflexed. 



Dalea is confined to the New World, where it is distributed from the central, 

 western, and southwestern regions of the United States through Mexico and Central 

 America to Chili, Peru, and the Galapagos Islands; usually herbs or low under- 

 shrubs. One species of the United States occasionally assumes the habit and attains 

 the size of a small tree. 



The generic name is in honor of Samuel Dale (1659-1739), an English botanist 

 and writer on the materia medica. 



1. Dalea spinosa, Gray. 



Leaves few, simple, irregularly scattered near the base of the spinose branchlets, 

 cuneate or linear-oblong, sessile or nearly sessile, marked by few large glands, 



