544 TREES OF NORTH AMERICA 



ing branches forming a low wide or irregular head, and branchlets when they first 

 appear somewhat striately angled, glabrous, pale yellow-brown or dark red-brown, 

 turning pale gray in their second year, and armed with occasional stout recurved 

 infrastipular chestnut-brown spines \' long, compressed toward the broad base and 

 very sharp-pointed, or rarely unarmed. Bark of the trunk about \' thick, furrowed, 

 divided by shallow furrows into broad ridges separating on the surface into thin 

 narrow scales. Wood very heavy, hard, close-grained, bright clear brown streaked 

 with red and yellow, with thin clear yellow sap wood of 6 or 7 layers of annual growth ; 

 valued and largely used as fuel. 



Distribution. Valley of the Guadalupe River in the neighborhood of New 

 Braunfels, Texas, to the Sierra Madre of Nuevo Leon; most abundant and of its 

 largest size south of the Rio Grande on dry gravelly mesas and foothills. 



4. Acacia Greggii, Gray. Cat's Claw. Ufia de Gato. 



Leaves 1/-3' long, pubescent or puberulous, with 1-3 pairs of pinnae, short 

 slender petioles furnished near the middle with a minute oblong chestnut-brown 

 gland, and linear stipules T ^' long and caducous ; pinme short-stalked, with 4-5 

 pairs of obovate oblique leaflets rounded or truncate at the apex and unequally con- 

 tracted at the base into short petiolules, thick and rigid, 2-3-nerved, reticulate- 

 veined, hoary -pubescent, ^'-^' long. Flowers fragrant, bright creamy yellow, in 

 dense oblong pubescent spikes, on peduncles '-f ' long, and fascicled usually 2 or 3 

 together toward the ends of the branches ; calyx obscurely 5-lobed, puberulous on 

 the outer surface, half as long as the petals slightly united at the base and pale- 

 tomentose on the margins; stamens \' long ; ovary long-stalked, covered with long 



pale hairs. Fruit fully grown at midsummer and hanging unopened on the branches 

 until winter or the following spring, compressed, straight or slightly falcate, obliquely 

 narrowed at the base into a short stalk, acute or rounded at the apex, more or less 

 contracted between the seeds, 2'-4' long, '-| ' wide, curling and often contorted when 

 fully ripe, the valves thin and membranaceous, thick-margined, light brown, con- 

 spicuously transversely reticulate-veined; seeds nearly orbicular, compressed, dark 

 brown and lustrous, \' in diameter, marked by small oval depressions. 



A tree, rarely 30 high, with a trunk 10'-12 f in diameter, numerous spreading 

 branches, and striately angled puberulous pale brown branchlets faintly tinged with 



